Geoffrey W. Coates

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Name: Coates, Geoffrey

Organization: Cornell University , USA

Department: Department of Chemistry and Chemical Biology

Title: (PhD)

TOPICS

Polymer

ionic polymerization

Chemicals
References

Phosphonium-Functionalized Polyethylene: A New Class of Base-Stable Alkaline Anion Exchange Membranes

Co-reporter:Kevin J. T. Noonan, Kristina M. Hugar, Henry A. Kostalik IV, Emil B. Lobkovsky, Héctor D. Abruña, and Geoffrey W. Coates

Journal of the American Chemical Society November 7, 2012 Volume 134(Issue 44) pp:18161-18164

Publication Date(Web):September 27, 2012

DOI:10.1021/ja307466s

A tetrakis(dialkylamino)phosphonium cation was evaluated as a functional group for alkaline anion exchange membranes (AAEMs). The base stability of [P(N(Me)Cy)4]+ was directly compared to that of [BnNMe3]+ in 1 M NaOD/CD3OD. The high base stability of [P(N(Me)Cy)4]+ relative to [BnNMe3]+ inspired the preparation of AAEM materials composed of phosphonium units attached to polyethylene. The AAEMs (hydroxide conductivity of 22 ± 1 mS cm–1 at 22 °C) were prepared using ring-opening metathesis polymerization, and their stabilities were evaluated in 15 M KOH at 22 °C and in 1 M KOH at 80 °C.

Allyl-Terminated Polypropylene Macromonomers: A Route to Polyolefin Elastomers with Excellent Elastic Behavior

Co-reporter:Hisashi Ohtaki, Fanny Deplace, Giang D. Vo, Anne M. LaPointe, Fumihiko Shimizu, Toshihiko Sugano, Edward J. Kramer, Glenn H. Fredrickson, and Geoffrey W. Coates

Macromolecules 2015 Volume 48(Issue 20) pp:7489-7494

Publication Date(Web):October 12, 2015

DOI:10.1021/acs.macromol.5b01975

We report the design, synthesis, and physical/mechanical properties of graft copolymers containing semicrystalline polypropylene side chains and amorphous ethylene/α-olefin copolymer backbones. These materials, a new class of semicrystalline, polyolefin-based thermoplastic elastomers, are made in two steps. First, allyl-terminated syndiotactic or isotactic polypropylene macromonomers are synthesized with controlled microstructure and molecular weight using bis(phenoxyimine)titanium or chiral ansa-zirconocene catalysts, respectively. Second, a pyridyl-amido hafnium catalyst is used to copolymerize the macromonomer, ethylene, and an α-olefin with precise control of composition and side chain incorporation. With highly crystalline polypropylene side chains and amorphous backbones of low glass-transition temperatures (<−55 °C), the samples have strain-to-break values up to 1400% and elastic recovery above 85% at maximum strains up to 1000%. The synthetic method described herein does not require the use of a living polymerization catalyst; in addition, the mechanical properties of these graft copolymers exceed those of the best linear block polyolefins.

Suppression of Lithium Dendrite Growth Using Cross-Linked Polyethylene/Poly(ethylene oxide) Electrolytes: A New Approach for Practical Lithium-Metal Polymer Batteries

Co-reporter:Rachna Khurana ; Jennifer L. Schaefer ; Lynden A. Archer

Journal of the American Chemical Society 2014 Volume 136(Issue 20) pp:7395-7402

Publication Date(Web):April 22, 2014

DOI:10.1021/ja502133j

Solid polymer electrolyte (SPE) membranes are a critical component of high specific energy rechargeable Li-metal polymer (LMP) batteries. SPEs exhibit low volatility and thus increase the safety of Li-based batteries compared to current state-of-the-art Li-ion batteries that use flammable small-molecule electrolytes. However, most SPEs exhibit low ionic conductivity at room temperature, and often allow the growth of lithium dendrites that short-circuit the batteries. Both of these deficiencies are significant barriers to the commercialization of LMP batteries. Herein we report a cross-linked polyethylene/poly(ethylene oxide) SPE with both high ionic conductivity (>1.0 × 10–4 S/cm at 25 °C) and excellent resistance to dendrite growth. It has been proposed that SPEs with shear moduli of the same order of magnitude as lithium could be used to suppress dendrite growth, leading to increased lifetime and safety for LMP batteries. In contrast to the theoretical predictions, the low-modulus (G′ ≈ 1.0 × 105 Pa at 90 °C) cross-linked SPEs reported herein exhibit remarkable dendrite growth resistance. These results suggest that a high-modulus SPE is not a requirement for the control of dendrite proliferation.

Carbonylative enantioselective meso-desymmetrization of cis-epoxides to trans-β-lactones: effect of salen-ligand electronic variation on enantioselectivity

Co-reporter:Michael Mulzer, Jessica R. Lamb, Zachary Nelson and Geoffrey W. Coates

Chemical Communications 2014 vol. 50(Issue 69) pp:9842-9845

Publication Date(Web):14 Jul 2014

DOI:10.1039/C4CC04397A

Carbonylation catalysts for the desymmetrization of meso-epoxides yielding enantioenriched trans-β-lactones are reported. Fine-tuning the electronic properties of the ligand further improved enantioselectivity. The sterics of the substrate dictated whether a given electronic variation decreased or increased enantioenrichment, revealing an unexpected relationship between the substrate's steric environment and the electronic nature of the optimal catalyst.

Investigating polypropylene-poly(ethylene oxide)-polypropylene triblock copolymers as solid polymer electrolytes for lithium batteries

Co-reporter:Nicholas P. Young, Didier Devaux, Rachna Khurana, Geoffrey W. Coates, Nitash P. Balsara

Solid State Ionics 2014 Volume 263() pp:87-94

Publication Date(Web):1 October 2014

DOI:10.1016/j.ssi.2014.05.012

Regioselective Carbonylation of trans-Disubstituted Epoxides to β-Lactones: A Viable Entry into syn-Aldol-Type Products

Co-reporter:Michael Mulzer ; Bryan T. Whiting

Journal of the American Chemical Society 2013 Volume 135(Issue 30) pp:10930-10933

Publication Date(Web):June 21, 2013

DOI:10.1021/ja405151n

Two new catalysts are reported for the regioselective carbonylation of trans-disubstituted epoxides to cis-β-lactones. The two catalysts display high and opposing selectivities, which generally are difficult to achieve for this class of epoxides. The resulting β-lactones are well-defined precursors for a wide variety of aldol-type compounds. Altogether, carbonylation of disubstituted epoxides is established as a viable and economical entry into syn- and anti-aldol products.

Synthesis and Polymerization of Bicyclic Ketals: A Practical Route to High-Molecular Weight Polyketals

Co-reporter:Bryan T. Whiting

Journal of the American Chemical Society 2013 Volume 135(Issue 30) pp:10974-10977

Publication Date(Web):July 19, 2013

DOI:10.1021/ja405581r

Polyketals are an important class of materials for drug delivery to sensitive tissues as they degrade in vivo to nonacidic species. We report the synthesis of high-molecular weight cyclic polyketals by the cationic ring-opening polymerization of bicyclic ketal monomers, which were prepared by the metal-catalyzed rearrangement of epoxy ketones. Three different cyclic polyketals with high molecular weights were synthesized using this protocol.

Synthesis and Ring-Opening Metathesis Polymerization of Norbornene-Terminated Syndiotactic Polypropylene

Co-reporter:Amelia M. Anderson-Wile and Geoffrey W. Coates, Finizia Auriemma, Claudio De Rosa, and Amelia Silvestre

Macromolecules 2012 Volume 45(Issue 19) pp:7863-7877

Publication Date(Web):September 19, 2012

DOI:10.1021/ma301073s

Using nonliving bis(phenoxyimine)titanium catalysts activated by methylaluminoxane (MAO) in the presence of propylene, allyl-terminated syndiotactic polypropylene macromonomers with varying tacticity ([rrrr] = 0.80 and 0.94) and molecular weight (Mn = 3600 and 5600 g/mol) were produced. The end-functionalized polymers were converted to hydroxyl- and subsequently norbornene-terminated macromonomers. Two series of syndiotactic polypropylene comb-polymers were synthesized through metathesis polymerization of the norbornene-functionalized polypropylene. The molecular weight (Mn = 46 000–172 000 g/mol) and polydispersity (Mw/Mn = 1.21–1.89) of the comb polymers was determined by gel permeation chromatography (GPC). Using differential scanning calorimetry (DSC), melting temperature (Tm) and crystallization temperature (Tc) were determined and both were observed to decrease with increasing conversion to poly(macromonomer). To the best of our knowledge, this is the first synthesis of comb-polymers from end-functionalized syndiotactic polypropylene.

Ring-Opening Copolymerization of Maleic Anhydride with Epoxides: A Chain-Growth Approach to Unsaturated Polyesters

Co-reporter:Angela M. DiCiccio

Journal of the American Chemical Society 2011 Volume 133(Issue 28) pp:10724-10727

Publication Date(Web):June 24, 2011

DOI:10.1021/ja203520p

We report the ring-opening copolymerization of maleic anhydride with a variety of epoxides catalyzed by a chromium(III) salen complex. Quantitative isomerization of the cis-maleate form of all polymers affords the trans-fumarate analogues. Addition of chain transfer reagents yields low Mn, narrow PDI polymer samples. This method provides access to a range of new unsaturated polyesters with versatile functionality, as well as the first synthesis of high molecular weight poly(propylene fumarate).

De Novo Asymmetric Synthesis of Fridamycin E

Co-reporter:Qian Chen, Michael Mulzer, Pei Shi, Penny J. Beuning, Geoffrey W. Coates, and George A. O’Doherty

Organic Letters 2011 Volume 13(Issue 24) pp:6592-6595

Publication Date(Web):November 22, 2011

DOI:10.1021/ol203041b

A de novo asymmetric synthesis of (R)- and (S)-fridamycin E has been achieved. The entirely linear route required only nine steps from commercially available starting materials (16% overall yield). Key transformations included a Claisen rearrangement, a Sharpless dihydroxylation and a cobalt-catalyzed epoxide carbonylation to give a β-lactone intermediate. Antibacterial activities were determined for both enantiomers using two strains of E. coli, with the natural (R)-enantiomer showing significant inhibition against a Gram-(+)-like imp strain (MIC = 8 μM).

A Catalytic Route to Ampakines and Their Derivatives

Co-reporter:Michael Mulzer and Geoffrey W. Coates

Organic Letters 2011 Volume 13(Issue 6) pp:1426-1428

Publication Date(Web):February 16, 2011

DOI:10.1021/ol200111a

A catalytic domino reaction that efficiently provides access to an important class of heterocycles, the ampakines, is reported. Our approach is based on the cobalt-catalyzed hydroformylation of dihydrooxazines and allows for the facile synthesis of the pharmaceutically interesting compound CX-614 and related substances.

Carbonylative Polymerization of Propylene Oxide: A Multicatalytic Approach to the Synthesis of Poly(3-Hydroxybutyrate)

Co-reporter:Erin W. Dunn

Journal of the American Chemical Society 2010 Volume 132(Issue 33) pp:11412-11413

Publication Date(Web):August 2, 2010

DOI:10.1021/ja1049862

We report a highly efficient method for the synthesis of poly(3-hydroxybutyrate) by the carbonylative polymerization of propylene oxide. The use of compatible epoxide carbonylation and lactone polymerization catalysts allows for a one-pot reaction that eliminates the need to isolate and purify the toxic β-butyrolactone intermediate.

Isospecific polymerization of racemic epoxides: a catalyst system for the synthesis of highly isotactic polyethers

Co-reporter:Peter C. B. Widger, Syud M. Ahmed, Wataru Hirahata, Renee M. Thomas, Emil B. Lobkovsky and Geoffrey W. Coates

Chemical Communications 2010 vol. 46(Issue 17) pp:2935-2937

Publication Date(Web):22 Mar 2010

DOI:10.1039/B926888J

A highly active bimetallic cobalt catalyst system is reported for the polymerization of racemic terminal epoxides to yield isotactic polyethers.

A Ring-Opening Metathesis Polymerization Route to Alkaline Anion Exchange Membranes: Development of Hydroxide-Conducting Thin Films from an Ammonium-Functionalized Monomer

Co-reporter:Timothy J. Clark ; Nicholas J. Robertson ; Henry A. Kostalik IV ; Emil B. Lobkovsky ; Paul F. Mutolo ; Héctor D. Abruña

Journal of the American Chemical Society 2009 Volume 131(Issue 36) pp:12888-12889

Publication Date(Web):August 21, 2009

DOI:10.1021/ja905242r

We report the development of a facile ring-opening olefin metathesis route to alkaline anion exchange membranes via the copolymerization of a tetraalkylammonium-functionalized norbornene with dicyclopentadiene. The thin films generated are mechanically strong and exhibit high hydroxide conductivities and exceptional methanol tolerance.

β-Amidoaldehydes viaoxazolinehydroformylation

Co-reporter:David S. Laitar, John W. Kramer, Bryan T. Whiting, Emil B. Lobkovsky and Geoffrey W. Coates

Chemical Communications 2009 (Issue 38) pp:5704-5706

Publication Date(Web):01 Sep 2009

DOI:10.1039/B913698C

4-Substituted oxazolines, which are readily synthesized from naturally occurring α-amino acids, are converted efficiently and stereospecifically to β-amidoaldehydes in the presence of synthesis gas and catalytic dicobalt octacarbonyl.

Cyclopolymerization of Nonconjugated Dienes with a Tridentate Phenoxyamine Hafnium Complex Supported by an sp3-C Donor: Isotactic Enchainment and Diastereoselective cis-Ring Closure

Co-reporter:Joseph B. Edson

Macromolecular Rapid Communications 2009 Volume 30( Issue 22) pp:1900-1906

Publication Date(Web):

DOI:10.1002/marc.200900422

On the mechanism of isospecific epoxide polymerization by salen cobalt(III) complexes: Evidence for solid-state catalysis

Co-reporter:Hiroharu Ajiro, Kathryn L. Peretti, Emil B. Lobkovsky and Geoffrey W. Coates

Dalton Transactions 2009 (Issue 41) pp:8828-8830

Publication Date(Web):30 Sep 2009

DOI:10.1039/B914573G

Mechanistic studies have revealed that the isospecific polymerization of epoxides by a discrete salen cobalt(III) catalyst occurs at the surface of the undissolved, crystalline complex.

Alkene Polymerization Catalysts Bearing Tridentate Phenoxyamine Ligands with sp3C Donors

Co-reporter:JosephB. Edson;Ivan Keresztes;EmilB. Lobkovsky ;GeoffreyW. Coates

ChemCatChem 2009 Volume 1( Issue 1) pp:122-130

Publication Date(Web):

DOI:10.1002/cctc.200900122

Abstract

The reaction of vinyl-appended phenoxyamine 2 with tetrabenzyltitanium provided the phenoxyaminetitanium(II) alkene complex [rac-Lig²TiBn], arising from intramolecular vinyl-group insertion followed by toluene elimination. Whereas [rac-Lig²TiBn] was inactive for olefin polymerization upon benzyl abstraction, treatment with ethylene led to the formation of stable titanacyclopentane complex [rac-Lig²(CH₂)₂TiBn]. Alternatively, six-membered metallacyclic complexes [rac-Lig¹ZrBn₂-a/b] and [rac-Lig¹HfBn₂-a/b] were obtained from reaction of vinyl-appended phenoxyamine 1 with tetrabenzylzirconium or tetrabenzylhafnium in a further rare example of intramolecular vinyl-group insertion into neutral tribenzyl group IV precursors. Living and isoselective polymerization of 1-hexene was promoted by [rac-Lig¹HfBn₂-a/b]/B(C₆F₅)₃ at 0 °C, whereas [rac-Lig¹ZrBn₂-a/b]/B(C₆F₅)₃ catalyzed the living and isoselective polymerization of propylene ([m⁴]=0.76) at 0 °C. This catalyst system was employed for the synthesis of a diblock copolymer featuring an isotactic polypropylene semicrystalline block and poly(ethylene-co-propylene) amorphous block.

Synthesis of a new olefin polymerization catalyst supported by an sp3-C donor via insertion of a ligand-appended alkene into the Hf–C bond of a neutral pyridylamidohafnium trimethyl complex

Co-reporter:Gregory J. Domski, Joseph B. Edson, Ivan Keresztes, Emil B. Lobkovsky and Geoffrey W. Coates

Chemical Communications 2008 (Issue 46) pp:6137-6139

Publication Date(Web):22 Oct 2008

DOI:10.1039/B811384J

A new living and isoselective propylene polymerization precatalyst was generated via the intramolecular insertion of a ligand-appended vinyl group into the Hf–C bond of a neutral pyridylamidohafnium trimethyl complex.

C2-Symmetric Ni(II) α-Diimines Featuring Cumyl-Derived Ligands: Synthesis of Improved Elastomeric Regioblock Polypropylenes

Co-reporter:Jeffrey M. Rose, Fanny Deplace, Nathaniel A. Lynd, Zhigang Wang, Atsushi Hotta, Emil B. Lobkovsky, Edward J. Kramer and Geoffrey W. Coates

Macromolecules 2008 Volume 41(Issue 24) pp:9548-9555

Publication Date(Web):November 26, 2008

DOI:10.1021/ma8019943

A series of chiral, nickel α-diimine complexes featuring ligands based on bulky cumyl-substituted aniline moieties was synthesized. Each complex was capable of polymerizing propylene upon activation with methylaluminoxane (MAO). The catalysts were shown to be highly regioregular and isoselective for propylene polymerization at low temperature (e.g., −60 °C), whereas at higher reaction temperatures (e.g., 0 °C) the catalysts furnished regioirregular polypropylene (rirPP) composed of 1,2- and 3,1-enchainments. Many of the catalysts exhibited living behavior for propylene polymerization from −78 to 0 °C. From the screening results, the best catalyst was selected and used to produce regioblock polypropylenes featuring three or five blocks. Mechanical testing revealed that the materials exhibited good elastomeric behavior and improved performance at elevated temperatures (e.g., 65 °C) over block copolymers synthesized using a previously prepared chiral, nickel α-diimine catalyst.

Catalytic Synthesis of 3-Amino Acid Derivatives from -Amino Acids

Co-reporter:ChristopherM. Byrne Dr.;TamaraL. Church Dr.;JohnW. Kramer ;GeoffreyW. Coates Dr.

Angewandte Chemie 2008 Volume 120( Issue 21) pp:4043-4047

Publication Date(Web):

DOI:10.1002/ange.200705310

Pre-Rate-Determining Selectivity in the Terpolymerization of Epoxides, Cyclic Anhydrides, and CO2: A One-Step Route to Diblock Copolymers

Co-reporter:RyanC. Jeske;JohnM. Rowley ;GeoffreyW. Coates

Angewandte Chemie 2008 Volume 120( Issue 32) pp:6130-6133

Publication Date(Web):

DOI:10.1002/ange.200801415

Pre-Rate-Determining Selectivity in the Terpolymerization of Epoxides, Cyclic Anhydrides, and CO2: A One-Step Route to Diblock Copolymers

Co-reporter:RyanC. Jeske;JohnM. Rowley ;GeoffreyW. Coates

Angewandte Chemie International Edition 2008 Volume 47( Issue 32) pp:6041-6044

Publication Date(Web):

DOI:10.1002/anie.200801415

Catalytic Synthesis of 3-Amino Acid Derivatives from -Amino Acids

Co-reporter:ChristopherM. Byrne Dr.;TamaraL. Church Dr.;JohnW. Kramer ;GeoffreyW. Coates Dr.

Angewandte Chemie International Edition 2008 Volume 47( Issue 21) pp:3979-3983

Publication Date(Web):

DOI:10.1002/anie.200705310

Living alkene polymerization: New methods for the precision synthesis of polyolefins

Co-reporter:Gregory J. Domski, Jeffrey M. Rose, Geoffrey W. Coates, Andrew D. Bolig, Maurice Brookhart

Progress in Polymer Science 2007 Volume 32(Issue 1) pp:30-92

Publication Date(Web):January 2007

DOI:10.1016/j.progpolymsci.2006.11.001

Precise control over product structure is the goal of all chemical synthesis. In the field of polymer synthesis, the structure of the resultant macromolecule is intimately linked to its material properties, which ultimately determines the potential applications for the polymeric material. Method development for alkene polymerization is becoming increasingly focused on achieving fine control over all aspects of macromolecular architecture; especially chain composition, molecular weight, and stereochemistry.One of the most powerful methods developed so far which is capable of furnishing a high degree of control over polymer architecture is living alkene polymerization catalyzed by transition metal complexes. Living polymerization is characterized by efficient initiation and chain termination/transfer rates that are negligible in comparison to the rate of propagation. Using living alkene polymerization methods, polymer chemists have synthesized materials with microstructures that were inaccessible just a decade ago. Specific examples include polyolefin-based block copolymers, end-functionalized polyolefins, and stereo/regioblock copolymers with well-defined block structures.This review is a comprehensive account of living alkene polymerization systems with special attention paid to systems developed in the last 5 years. The text is organized by polymer type, which will allow those seeking to construct a specific polymer architecture to quickly identify relevant methodologies.

Copolymerization of cyclohexene oxide and carbon dioxide using (salen)Co(III) complexes: synthesis and characterization of syndiotactic poly(cyclohexene carbonate)

Co-reporter:Claire T. Cohen, Christophe M. Thomas, Kathryn L. Peretti, Emil B. Lobkovsky and Geoffrey W. Coates

Dalton Transactions 2006 (Issue 1) pp:237-249

Publication Date(Web):24 Nov 2005

DOI:10.1039/B513107C

Synthetic routes to a series of new (salen)CoX (salen = N,N′-bis(salicylidene)-1,2-diaminoalkane; X = halide or carboxylate) species are described and the X-ray crystal structures of two (salen-1)CoX (salen-1 = N,N′-bis(3,5-di-tert-butylsalicylidene)-1,2-diaminocyclohexane; X = Cl, I) complexes are presented. (R,R)-(salen-1)CoX (X = Cl, Br, I, OAc, pentafluorobenzoate (OBzF5)) catalysts are active for the copolymerization of cyclohexene oxide (CHO) and CO2, yielding syndiotactic poly(cyclohexene carbonate) (PCHC), a previously unreported PCHC microstructure. Variation of the salen ligand and reaction conditions, as well as the inclusion of [PPN]Cl ([PPN]Cl = bis(triphenylphosphine)iminium chloride) cocatalysts, has dramatic effects on the polymerization rate and the resultant PCHC tacticity. Catalysts rac-(salen-6)CoX (salen-6 = N,N′-bis(3,5-di-tert-butylsalicylidene)-1,2-diaminopropane; X = Br, OBzF5) have high activities for CHO/CO2 copolymerization, yielding syndiotactic PCHCs with up to 81% r-centered tetrads. Using Bernoullian statistical methods, PCHC tetrad and triad sequences were assigned in the 13C NMR spectra of these polymers in the carbonyl and methylene regions, respectively.

Two-dimensional double metal cyanide complexes: highly active catalysts for the homopolymerization of propylene oxide and copolymerization of propylene oxide and carbon dioxide

Co-reporter:Nicholas J. Robertson, Zengquan Qin, Gregory C. Dallinger, Emil B. Lobkovsky, Stephen Lee and Geoffrey W. Coates

Dalton Transactions 2006 (Issue 45) pp:5390-5395

Publication Date(Web):05 Sep 2006

DOI:10.1039/B607963F

The synthesis of two-dimensional double metal cyanide complexes of the formula Co(H2O)2[M(CN)4]·4H2O (M = Ni, Pd or Pt) and the X-ray crystal structure of Co(H2O)2[Pd(CN)4]·4H2O are presented. The anhydrous forms of these complexes were found to be effective catalyst precursors for the homopolymerization of propylene oxide as well as the random copolymerization of propylene oxide and carbon dioxide to produce poly(propylene oxide-co-propylene carbonate) with no propylene carbonate byproduct. A detailed copolymer microstructure is proposed.

Alternating copolymerization of propylene oxide and carbon dioxide with highly efficient and selective (salen)Co(III) catalysts: Effect of ligand and cocatalyst variation

Co-reporter:Claire T. Cohen;Claire T. Cohen

Journal of Polymer Science Part A: Polymer Chemistry 2006 Volume 44(Issue 17) pp:5182-5191

Publication Date(Web):28 JUL 2006

DOI:10.1002/pola.21606

Synthetic routes to a series of new (salen)CoX (salen = N,N′-bis(salicylidene)-1,2-diaminoalkane; X = Br or pentafluorobenzoate (OBzF₅)) species are described. Several of these complexes are active for the copolymerization of propylene oxide (PO) and CO₂, yielding regioregular poly(propylene carbonate) (PPC) without the generation of propylene carbonate byproduct. Variation of the salen ligand, as well as the inclusion of organic-based ionic or Lewis basic cocatalysts, has dramatic effects on the resultant (salen) CoX catalytic activity. Highly active (R,R)-(salen-1)CoOBzF₅ (salen-1 = N,N′-bis(3,5- di-tert-butylsalicylidene)-1,2-diaminocyclohexane) catalysts with [Ph₄P]Cl or [PPN]Y ([PPN] = bis(triphenylphosphine)iminium; Y = Cl or OBzF₅) cocatalysts exhibited turnover frequencies up to 720 h⁻¹ for rac-PO/CO₂ copolymerization, yielding PPC with greater than 90% head-to-tail connectivity. Additionally, the (R,R)-(salen-1)CoOBzF₅/[PPN]Cl catalyst system demonstrated a k_rel of 9.7 for the enchainment of (S)- over (R)-PO when the copolymerization was carried out at low temperatures. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 5182–5191, 2006

Dehydrogenation of aliphatic polyolefins catalyzed by pincer-ligated iridium complexes

Co-reporter:Amlan Ray, Keming Zhu, Yury V. Kissin, Anna E. Cherian, Geoffrey W. Coates and Alan S. Goldman

Chemical Communications 2005 (Issue 27) pp:3388-3390

Publication Date(Web):27 May 2005

DOI:10.1039/B502120K

We report the first example of the catalytic dehydrogenation of aliphatic polyolefins to give partially unsaturated hydrocarbon polymers.

Cross metathesis functionalization of polyolefins

Co-reporter:Robert T. Mathers and Geoffrey W. Coates

Chemical Communications 2004 (Issue 4) pp:422-423

Publication Date(Web):22 Jan 2004

DOI:10.1039/B313954A

A cross metathesis strategy is reported for the post-polymerization functionalization of the pendant vinyl groups present in a range of polyolefin architectures. This represents a general strategy for the synthesis of tailored random and block copolymers as well as homopolymers.

Diskrete Metallkatalysatoren zur Copolymerisation von CO2 mit Epoxiden: Entdeckung, Reaktivität, Optimierung, Mechanismus

Co-reporter:Geoffrey W. Coates ;David R. Moore Dr.

Angewandte Chemie 2004 Volume 116(Issue 48) pp:

Publication Date(Web):23 NOV 2004

DOI:10.1002/ange.200460442

Synthetische Polymere werden zum weit überwiegenden Teil aus dem Rohstoff Erdöl hergestellt und sind nicht erneuerbar. Demnach besteht ein steigender Bedarf an Herstellungsverfahren für Polymere aus erneuerbaren Quellen und ein zunehmendes Interesse an biologisch abbaubaren polymeren Materialien. Polycarbonate, die aus CO₂ und Epoxiden zugänglich sind, haben das Potenzial, diese Anforderungen zu erfüllen. Seit der Entdeckung von Katalysatoren zur Copolymerisation von CO₂ und Epoxiden in den späten 60er Jahren durch Inoue wurde ein erheblicher Forschungsaufwand in die Entwicklung von Katalysatoren mit verbesserter Aktivität und Selektivität investiert. Dieser Aufsatz behandelt wohldefinierte Katalysatoren für die Epoxid-CO₂-Copolymerisation und verwandte Reaktionen.

Discrete Metal-Based Catalysts for the Copolymerization of CO2 and Epoxides: Discovery, Reactivity, Optimization, and Mechanism

Co-reporter:Geoffrey W. Coates ;David R. Moore Dr.

Angewandte Chemie International Edition 2004 Volume 43(Issue 48) pp:

Publication Date(Web):23 NOV 2004

DOI:10.1002/anie.200460442

Most synthetic polymers are made from petroleum feedstocks. Given the non-renewable nature of these materials, there is increasing interest in developing routes to polymeric materials from renewable resources. In addition, there is a growing demand for biodegradable polymeric materials. Polycarbonates made from CO₂ and epoxides have the potential to meet these goals. Since the discovery of catalysts for the copolymerization of CO₂ and epoxides in the late 1960's by Inoue, a significant amount of research has been directed toward the development of catalysts of improved activity and selectivity. Reviewed here are well-defined catalysts for epoxide–CO₂ copolymerization and related reactions.

Chiral anilines: development of C2-symmetric, late-transition metal catalysts for isoselective 2-butene polymerization

Co-reporter:Anna E. Cherian, Emil B. Lobkovsky and Geoffrey W. Coates

Chemical Communications 2003 (Issue 20) pp:2566-2567

Publication Date(Web):11 Sep 2003

DOI:10.1039/B307659H

Chiral nickel catalysts were synthesized and used for the isoselective polymerization of trans-2-butene.

Structure and reactivity of mono- and dinuclear diiminate zinc alkyl complexes

Co-reporter:Scott D Allen, David R Moore, Emil B Lobkovsky, Geoffrey W Coates

Journal of Organometallic Chemistry 2003 Volume 683(Issue 1) pp:137-148

Publication Date(Web):7 October 2003

DOI:10.1016/S0022-328X(03)00544-8

The synthesis, structure and reactivity of several diiminate ligands are presented. The syntheses of five representative β-diiminate (BDI) zinc alkyl complexes and one β-oxo-δ-diiminate (BODDI) zinc alkyl are described. BDI ligands with varying backbone and N-aryl substituents display different solid state structures. [(BDI)ZnR] are synthesized by the reaction of (BDI)H with ZnR2 in quantitative yield. Previously reported (BDI-1)ZnEt is a three-coordinate monomer in the solid state whereas [(BDI-3)ZnEt]∞ [(BDI-3)=2-((2,6-diisopropylphenyl)amido)-3-cyano-4-((2,6-diisopropylphenyl)imino-2-pentene] and [(BDI-4)ZnEt]∞ [(BDI-4)=2-((2,6-diethylphenyl)amido)-3-cyano-4-((2,6-diethylphenyl)imino-2-pentene] form one dimensional coordination polymers. The bimetallic complex [(BODDI-1)(ZnEt)2] [(BODDI-1)=2,6-bis((2,6-diisopropylphenyl)amido)-2,5-heptadien-4-one] is prepared through the reaction of (BODDI-1)H2 with two equivalents ZnEt2. Both [(BDI)ZnEt] and [(BODDI)ZnEt] complexes react with acetic acid to give the acetate complexes in moderate to high yields, offering a superior synthetic route to these complexes. [(BDI)ZnR] [BDI=(BDI-3) or 1,1,1-trifluoro-2-((2,6-diisopropylphenyl)amido)-4-((2,6-diethylphenyl)imino-2-pentene), (BDI-5)] complexes react with MeOH to produce [{(BDI)Zn(μ-OMe)}2Zn(μ-OMe)2] in moderate yields. The molecular structures of [(BDI-3)ZnEt], [(BDI-4)ZnEt], [(BODDI-1)(ZnEt)2], [(BODDI-1)Zn2(μ-OAc)2], [{(BDI-3)Zn(μ-OMe)}2Zn(μ-OMe)2] and [{(BDI-5)Zn(μ-OMe)}2Zn(μ-OMe)2] have been determined by X-ray diffraction.The synthesis, structure and reactivity of five representative β-diiminate (BDI) zinc alkyl complexes and one β-oxo-δ-diiminate (BODDI) zinc alkyl is described.

Cobalt-Based Complexes for the Copolymerization of Propylene Oxide and CO2: Active and Selective Catalysts for Polycarbonate Synthesis

Co-reporter:Zengquan Qin Dr.;Christophe M. Thomas Dr.;Stephen Lee Dr. Dr.

Angewandte Chemie 2003 Volume 115(Issue 44) pp:

Publication Date(Web):23 OCT 2003

DOI:10.1002/ange.200352605

Kohlendioxid wäre ein idealer Rohstoff für die chemische Synthese, stünde seine thermodynamische Stabilität nicht einer Verwendung in größerem Umfang im Wege. Hier werden aktive Cobalt-Katalysatoren für die Copolymerisation von Propylenoxid und CO₂ beschrieben (siehe Schema), die Polycarbonat mit ausgezeichneter Regioselektivität und ohne cyclische Carbonate als Nebenprodukte liefern.

Cobalt-Based Complexes for the Copolymerization of Propylene Oxide and CO2: Active and Selective Catalysts for Polycarbonate Synthesis

Co-reporter:Zengquan Qin Dr.;Christophe M. Thomas Dr.;Stephen Lee Dr. Dr.

Angewandte Chemie International Edition 2003 Volume 42(Issue 44) pp:

Publication Date(Web):23 OCT 2003

DOI:10.1002/anie.200352605

CO₂is an ideal feedstock for chemical synthesis; unfortunately its thermodynamic stability is a barrier to widespread use. Active cobalt catalysts for the copolymerization of propylene oxide and CO₂ are reported (see scheme; L=N,N′-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediamine), which have excellent regioselectivity for polycarbonate synthesis without concomitant production of cyclic carbonate by-products.

Syndiospecific Living Catalysts for Propylene Polymerization: Effect of Fluorination on Activity, Stereoselectivity, and Termination

Co-reporter:Andrew F. Mason;Jun Tian;Emil B. Lobkovsky;Philip D. Hustad

Israel Journal of Chemistry 2002 Volume 42(Issue 4) pp:301-306

Publication Date(Web):8 MAR 2010

DOI:10.1560/XKLD-HWTH-Q45E-1V9G

The polymerization of propylene using a variety of fluorinated bis(phenoxyimine)titanium complexes is reported. The synthesis of ten complexes containing varying fluorinated N-aryl substituents is described. X-ray structural and solution NMR data indicate that these complexes are C₂-symmetric in the solid state, although in some cases C₁-symmetric isomers are observed in solution. When activated with methylalumoxane, all complexes formed syndiotactic polypropylene. Catalysts with ortho-fluorine substituents formed polymers with very narrow molecular weight distributions, indicative of a living polymerization. Catalysts with fluorine in at least the ortho and para positions exhibited the highest syndio-specificities. Catalysts with meta- or para-fluorine-containing substituents were more active for propylene polymerization than the corresponding non-fluorinated catalyst.

Catalysts for the Living Insertion Polymerization of Alkenes: Access to New Polyolefin Architectures Using Ziegler–Natta Chemistry

Co-reporter:Geoffrey W. Coates Dr.;Phillip D. Hustad;Stefan Reinartz Dr.

Angewandte Chemie International Edition 2002 Volume 41(Issue 13) pp:

Publication Date(Web):1 JUL 2002

DOI:10.1002/1521-3773(20020703)41:13<2236::AID-ANIE2236>3.0.CO;2-3

Coordination–insertion polymerization systems have long been superior to their anionic, cationic, and radical polymerization counterparts with regard to stereochemical control. However, until five years ago, these metal-based insertion methods were inferior to ionic and radical mechanisms in the category of living polymerization, which is simply a polymerization that occurs with rapid initiation and negligible chain termination or transfer. In the last half decade, the living insertion polymerization of unactivated olefins has emerged as a powerful tool for the synthesis of new polymer architectures. Materials available today by this route range from simple homopolymers such as linear and branched polyethylene, to atactic or tactic poly(α-olefins), to end-functionalized polymers and block copolymers. This review article summarizes recent developments in this rapidly growing research area at the interface of synthetic and mechanistic organometallic chemistry, polymer chemistry, and materials science. While special emphasis is placed on polymer properties and novel polymeric architectures, most of which were inaccessible just a decade ago, important achievements with respect to ligand and catalyst design are also highlighted.

[Lewis Acid]+[Co(CO)4]− Complexes: A Versatile Class of Catalysts for Carbonylative Ring Expansion of Epoxides and Aziridines

Co-reporter:Viswanath Mahadevan Dr.;Yutan D. Y. L. Getzler Dr.

Angewandte Chemie 2002 Volume 114(Issue 15) pp:

Publication Date(Web):11 OCT 2005

DOI:10.1002/1521-3757(20020802)114:15<2905::AID-ANGE2905>3.0.CO;2-C

Mit Lewis-Säuren zu β-Lactonen und β-Lactamen: Mit Komplexen des Typs [Lewis-Säure]⁺[Co(CO)₄]⁻, z. B. 1 und 2, lässt sich in die C-O- und die C-N-Bindung von Epoxiden und Aziridinen effizient, stereoselektiv und unter milden Bedingungen eine Carbonylgruppe inserieren, wobei β-Lactone bzw. β-Lactame entstehen. Merkmal beider mechanistisch gleichen Reaktionen ist die Konfigurationsumkehr an der Position der CO-Insertion.

Electronic and Steric Effects on Catalysts for CO2/Epoxide Polymerization: Subtle Modifications Resulting in Superior Activities

Co-reporter:David R. Moore;Ming Cheng;Emil B. Lobkovsky

Angewandte Chemie 2002 Volume 114(Issue 14) pp:

Publication Date(Web):15 JUL 2002

DOI:10.1002/1521-3757(20020715)114:14<2711::AID-ANGE2711>3.0.CO;2-3

Der vielleicht attraktivste Rohstoff auf Kohlenstoffbasis ist – wegen seiner guten Verfügbarkeit und geringen Toxizität – das Treibhausgas CO₂; daher ist seine Nutzung schon seit längerem ein wichtiges Forschungsgebiet. Hier werden β-Diiminat-Zink-Katalysatoren mit einheitlichen Katalysatorzentren vorgestellt, die außerordentlich aktiv bei der CO₂/Epoxid-Copolymerisation sind (siehe Schema).

Electronic and Steric Effects on Catalysts for CO2/Epoxide Polymerization: Subtle Modifications Resulting in Superior Activities

Co-reporter:David R. Moore;Ming Cheng;Emil B. Lobkovsky

Angewandte Chemie International Edition 2002 Volume 41(Issue 14) pp:

Publication Date(Web):15 JUL 2002

DOI:10.1002/1521-3773(20020715)41:14<2599::AID-ANIE2599>3.0.CO;2-N

CO₂is perhaps the most attractive carbon-based feedstock owing to its abundance and low toxicity. Utilization of this contributor to global warming is a long-standing goal. Reported here are new single-site β-diiminate zinc catalysts that exhibit unprecedented activities for CO₂/epoxide polymerization (see scheme).

[Lewis Acid]+[Co(CO)4]− Complexes: A Versatile Class of Catalysts for Carbonylative Ring Expansion of Epoxides and Aziridines

Co-reporter:Viswanath Mahadevan Dr.;Yutan D. Y. L. Getzler Dr.

Angewandte Chemie International Edition 2002 Volume 41(Issue 15) pp:

Publication Date(Web):2 AUG 2002

DOI:10.1002/1521-3773(20020802)41:15<2781::AID-ANIE2781>3.0.CO;2-S

Efficient carbonyl insertion into CO and CN bonds using [Lewis acid]⁺[Co(CO)₄]⁻ complexes 1 and 2 gives regio- and stereoselective carbonylation of a variety of epoxides and aziridines to yield β-lactones and β-lactams, respectively. Both transformations are proposed to occur by the same mechanism, yielding products with inversion of configuration at the site of CO insertion.

Polymerization of Ureidopyrimidinone-Functionalized Olefins by Using Late-Transition Metal Ziegler–Natta Catalysts: Synthesis of Thermoplastic Elastomeric Polyolefins

Co-reporter:Lee R. Rieth;Robert F. Eaton

Angewandte Chemie 2001 Volume 113(Issue 11) pp:

Publication Date(Web):28 MAY 2001

DOI:10.1002/1521-3757(20010601)113:11<2211::AID-ANGE2211>3.0.CO;2-L

Die Natur als Vorbild: Die Bildung spezifischer Wasserstoffbrücken, eine wesentliche Grundlage für Prozesse in lebenden Organismen, lässt sich im Grenzgebiet von supramolekularer Chemie und homogener Katalyse gezielt einsetzen, so bei der Synthese neuartiger Elastomere (siehe schematische Darstellung), deren Eigenschaften auf starken intermolekularen Wasserstoffbrücken beruhen.

Enantiomerically-enriched organic reagents via polymer synthesis: enantioselective copolymerization of cycloalkene oxides and CO2 using homogeneous, zinc-based catalysts

Co-reporter:Ming Cheng, Nicholas A. Darling, Emil B. Lobkovsky and Geoffrey W. Coates

Chemical Communications 2000 (Issue 20) pp:2007-2008

Publication Date(Web):10 Oct 2000

DOI:10.1039/B005537I

Enantiomerically pure zinc complexes have been designed and synthesized for the enantioselective copolymerization of cycloalkene oxides and CO2.

Development of a Diversity-Based Approach for the Discovery of Stereoselective Polymerization Catalysts: Identification of a Catalyst for the Synthesis of Syndiotactic Polypropylene

Co-reporter:Jun Tian Dr.;Geoffrey W. Coates

Angewandte Chemie 2000 Volume 112(Issue 20) pp:

Publication Date(Web):13 OCT 2000

DOI:10.1002/1521-3757(20001016)112:20<3772::AID-ANGE3772>3.0.CO;2-D

Influence of Perfluoroarene–Arene Interactions on the Phase Behavior of Liquid Crystalline and Polymeric Materials

Co-reporter:Marcus Weck;Alex R. Dunn;Kozo Matsumoto;Emil B. Lobkovsky;Robert H. Grubbs

Angewandte Chemie International Edition 1999 Volume 38(Issue 18) pp:

Publication Date(Web):15 SEP 1999

DOI:10.1002/(SICI)1521-3773(19990917)38:18<2741::AID-ANIE2741>3.0.CO;2-1

A stabilization of the liquid-crystalline mesophase and thus an enlarged temperature range of the mesogenic phase is achieved by adding perfluorotriphenylene to a chiral liquid-crystalline triphenylene. This mesophase is based on 1:1 perfluoroarene–arene interactions (see picture). In a polymer with triphenylenes as mesogens in the side chains, the addition of perfluorotriphenylene led to crystallization.

Einfluß von Perfluoraren-Aren-Wechselwirkungen auf das Phasenverhalten von flüssigkristallinen und polymeren Materialien

Co-reporter:Marcus Weck;Alex R. Dunn;Kozo Matsumoto;Emil B. Lobkovsky;Robert H. Grubbs

Angewandte Chemie 1999 Volume 111(Issue 18) pp:

Publication Date(Web):15 SEP 1999

DOI:10.1002/(SICI)1521-3757(19990917)111:18<2909::AID-ANGE2909>3.0.CO;2-U

Eine Stabilisierung der flüssigkristallinen Mesophase und damit eine Erweiterung des Temperaturbereiches der mesogenen Phase wird durch Zugabe von Perfluortriphenylen zu einem chiralen, flüssigkristallinen Triphenylen erreicht. Sie beruht auf 1:1-Perfluoraren-Aren-Wechselwirkungen (siehe Bild). Bei einem Polymer mit Triphenyleneinheiten als Mesogenen in den Seitenketten führt die Zugabe von Perfluortriphenylen zur Kristallisation.

Phosphonium-Functionalized Polyethylene: A New Class of Base-Stable Alkaline Anion Exchange Membranes

Co-reporter:Kevin J. T. Noonan ; Kristina M. Hugar ; Henry A. Kostalik ; IV; Emil B. Lobkovsky ; Héctor D. Abruña

Journal of the American Chemical Society () pp:

Publication Date(Web):September 27, 2012

DOI:10.1021/ja307466s

Meinwald-type rearrangement of monosubstituted epoxides to methyl ketones using an [Al porphyrin]+[Co(CO)4]− catalyst

Co-reporter:Jessica R. Lamb, Yukyung Jung and Geoffrey W. Coates

Inorganic Chemistry Frontiers 2015 - vol. 2(Issue 4) pp:NaN349-349

Publication Date(Web):2015/02/16

DOI:10.1039/C4QO00324A

A Meinwald-type rearrangement of monosubstituted epoxides to methyl ketones using a well-defined aluminum porphyrin catalyst is reported. This reaction shows good functional group tolerance under mild reaction conditions to selectively give methyl ketones in excellent yields.

Carbonylative enantioselective meso-desymmetrization of cis-epoxides to trans-β-lactones: effect of salen-ligand electronic variation on enantioselectivity

Co-reporter:Michael Mulzer, Jessica R. Lamb, Zachary Nelson and Geoffrey W. Coates

Chemical Communications 2014 - vol. 50(Issue 69) pp:NaN9845-9845

Publication Date(Web):2014/07/14

DOI:10.1039/C4CC04397A

Isospecific polymerization of racemic epoxides: a catalyst system for the synthesis of highly isotactic polyethers

Co-reporter:Peter C. B. Widger, Syud M. Ahmed, Wataru Hirahata, Renee M. Thomas, Emil B. Lobkovsky and Geoffrey W. Coates

Chemical Communications 2010 - vol. 46(Issue 17) pp:NaN2937-2937

Publication Date(Web):2010/03/22

DOI:10.1039/B926888J

A highly active bimetallic cobalt catalyst system is reported for the polymerization of racemic terminal epoxides to yield isotactic polyethers.

Synthesis of a new olefin polymerization catalyst supported by an sp3-C donor via insertion of a ligand-appended alkene into the Hf–C bond of a neutral pyridylamidohafnium trimethyl complex

Co-reporter:Gregory J. Domski, Joseph B. Edson, Ivan Keresztes, Emil B. Lobkovsky and Geoffrey W. Coates

Chemical Communications 2008(Issue 46) pp:NaN6139-6139

Publication Date(Web):2008/10/22

DOI:10.1039/B811384J

β-Amidoaldehydes viaoxazolinehydroformylation

Co-reporter:David S. Laitar, John W. Kramer, Bryan T. Whiting, Emil B. Lobkovsky and Geoffrey W. Coates

Chemical Communications 2009(Issue 38) pp:NaN5706-5706

Publication Date(Web):2009/09/01

DOI:10.1039/B913698C

On the mechanism of isospecific epoxide polymerization by salen cobalt(III) complexes: Evidence for solid-state catalysis

Co-reporter:Hiroharu Ajiro, Kathryn L. Peretti, Emil B. Lobkovsky and Geoffrey W. Coates

Dalton Transactions 2009(Issue 41) pp:NaN8830-8830

Publication Date(Web):2009/09/30

DOI:10.1039/B914573G

Mechanistic studies have revealed that the isospecific polymerization of epoxides by a discrete salen cobalt(III) catalyst occurs at the surface of the undissolved, crystalline complex.