Co-reporter:Qinqin Shi, Eric S. Andreansky, Seth R. Marder, and Simon B. Blakey
The Journal of Organic Chemistry October 6, 2017 Volume 82(Issue 19) pp:10139-10139
Publication Date(Web):September 8, 2017
DOI:10.1021/acs.joc.7b01604
Coronenediimide (CDI) derivatives have a planar structure, a reasonably high electron affinity, and a rigid and extended delocalized π-system. Therefore, this core and variants thereof may be promising building blocks for the synthesis of electron transport materials. Herein, we have synthesized thiazole-semicoronenediimides (TsCDIs) and -coronenediimides (TCDIs) by a two-step process from a perylenediimide (PDI) precursor. Conditions for C–H arylation and heteroarylation of the thiazole moiety of this core were developed and were successfully used for the synthesis of dimer, triad, and polymeric materials. The optical and electrochemical properties of these materials and their monomers were examined as a function of side-chain modification and π-extension. With their broad optical absorption and low reduction potentials, these materials could be candidates as organic semiconductors for applications in OFETs and as nonfullerene acceptors.
Co-reporter:Aidi Kong, Eric S. Andreansky, and Simon B. Blakey
The Journal of Organic Chemistry April 21, 2017 Volume 82(Issue 8) pp:4477-4477
Publication Date(Web):April 10, 2017
DOI:10.1021/acs.joc.7b00503
Mattogrossine is an indole alkaloid isolated from Strychnos mattogrossensis that contains an unusual tetrahydrofuran ring with a concomitant hemiacetal in its structure. While tetrahydrofuran intermediates have been used in the synthesis of other strychnos alkaloids, no investigations have been performed into the synthesis of alkaloids containing this structure. We have developed an oxocarbenium-ion-initiated cascade annulation that provides us access to the ABCD ring structure of mattogrossine.
Co-reporter:Jacob S. Burman; Dr. Simon B. Blakey
Angewandte Chemie 2017 Volume 129(Issue 44) pp:13854-13857
Publication Date(Web):2017/10/23
DOI:10.1002/ange.201707021
AbstractA method for catalytic intermolecular allylic C−H amination of trans-disubstituted olefins is reported. The reaction is efficient for a range of common nitrogen nucleophiles bearing one electron-withdrawing group, and proceeds under mild reaction conditions. Good levels of regioselectivity are observed for a wide range of electronically diverse trans-β-alkyl styrene substrates.
Co-reporter:A. Kong;D. E. Mancheno;N. Boudet;R. Delgado;E. S. Andreansky;S. B. Blakey
Chemical Science (2010-Present) 2017 vol. 8(Issue 1) pp:697-700
Publication Date(Web):2016/12/19
DOI:10.1039/C6SC03578G
The first total synthesis of malagashanine, a chloroquine potentiating indole alkaloid, is presented. A highly stereoselective cascade annulation reaction was developed to generate the tetracyclic core of the Malagasy alkaloids. This chemistry is likely to be broadly applicable to the synthesis of other members of this stereochemically unique family of natural products.
Co-reporter:Qinqin Shi; Siyuan Zhang; Junxiang Zhang; Victoria F. Oswald; Aram Amassian; Seth R. Marder
Journal of the American Chemical Society 2016 Volume 138(Issue 12) pp:3946-3949
Publication Date(Web):March 21, 2016
DOI:10.1021/jacs.5b12259
An efficient iodination reaction of electron-deficient heterocycles is described. The reaction utilizes KOtBu as an initiator and likely proceeds by a radical anion propagation mechanism. This new methodology is particularly effective for functionalization of building blocks for electron transport materials. Its utility is demonstrated with the synthesis of a new perylenediimide–thiazole non-fullerene acceptor capable of delivering a power conversion efficiency of 4.5% in a bulk-heterojunction organic solar cell.
Co-reporter:N. Mace Weldy, A. G. Schafer, C. P. Owens, C. J. Herting, A. Varela-Alvarez, S. Chen, Z. Niemeyer, D. G. Musaev, M. S. Sigman, H. M. L. Davies and S. B. Blakey
Chemical Science 2016 vol. 7(Issue 5) pp:3142-3146
Publication Date(Web):05 Feb 2016
DOI:10.1039/C6SC00190D
The intermolecular enantioselective C–H functionalization with acceptor-only metallocarbenes is reported using a new family of Ir(III)-bis(imidazolinyl)phenyl catalysts, developed based on the interplay of experimental and computational insights. The reaction is tolerant of a variety of diazoacetate precursors and is found to be heavily influenced by the steric and electronic properties of the substrate. Phthalan and dihydrofuran derivatives are functionalized in good yields and excellent enantioselectivities.
Co-reporter:Eric S. Andreansky and Simon B. Blakey
Organic Letters 2016 Volume 18(Issue 24) pp:6492-6495
Publication Date(Web):December 1, 2016
DOI:10.1021/acs.orglett.6b03406
The akuammiline alkaloids are a family of indole monoterpene natural products known for their polycyclic cage-like structures. An iminium ion cascade annulation approach was developed, simultaneously synthesizing both the C and D rings of these natural products by annulation onto a protected indole ring. This reaction allowed the synthesis of a key tetracyclic intermediate toward these natural products. This tetracycle was used for the synthesis of the pentacyclic methanoquinolizidine core present in such alkaloids as akuammiline and strictamine as well as the pentacyclic furoindoline core found in pseudoakuammigine.
Co-reporter:Andrew G. Schafer and Simon B. Blakey
Chemical Society Reviews 2015 vol. 44(Issue 17) pp:5969-5980
Publication Date(Web):05 Jun 2015
DOI:10.1039/C5CS00354G
Recently, several novel iridium complexes have been shown to catalyse group transfer reactions in a highly selective fashion. Rhodium complexes, and in particular dirhodium tetracarboxylate salts, have proven to be a remarkably useful class of catalysts for these reactions through several decades of development. Recent results suggest that iridium may offer opportunities to address challenges in this chemistry and provide complementary reactivity patterns. This tutorial review outlines the recent developments in Ir-catalyzed enantioselective group transfer chemistry with highlights on examples which display this unique reactivity.
Co-reporter:Omar Villanueva, Nina Mace Weldy, Simon B. Blakey and Cora E. MacBeth
Chemical Science 2015 vol. 6(Issue 11) pp:6672-6675
Publication Date(Web):30 Jul 2015
DOI:10.1039/C5SC01162K
A dinuclear Co(II) complex supported by a modular, tunable redox-active ligand system is capable of selective C–H amination to form indolines from aryl azides in good yields at low (1 mol%) catalyst loading. The reaction is tolerant of medicinally relevant heterocycles, such as pyridine and indole, and can be used to form 5-, 6-, and 7-membered rings. The synthetic versatility obtained using low loadings of an earth abundant transition metal complex represents a significant advance in catalytic C–H amination technology.
Co-reporter:Dr. Daniel Morton ; Simon B. Blakey
ChemCatChem 2015 Volume 7( Issue 4) pp:577-578
Publication Date(Web):
DOI:10.1002/cctc.201402945
Co-reporter:Jennifer L. Bon, Daijun Feng, Seth R. Marder, and Simon B. Blakey
The Journal of Organic Chemistry 2014 Volume 79(Issue 16) pp:7766-7771
Publication Date(Web):July 31, 2014
DOI:10.1021/jo501416j
Benzobisthiazole and thiazolothiazole derivatives are useful components in a variety of organic electronics devices resulting from their absorption, electroluminescence, and charge-transport properties. A convenient synthesis of these molecules via palladium/copper cocatalyzed C–H bond functionalization is described. Reaction conditions were optimized in a bromobenzene/benzobisthiazole system that allowed for the one-pot functionalization of both thioimidate positions of benzobisthiazole. The extension of this methodology to the synthesis of cruciform architectures and the functionalization of thiazolothiazole is also described.
Co-reporter:Clayton P. Owens, Adrián Varela-Álvarez, Vyacheslav Boyarskikh, Djamaladdin G. Musaev, Huw M. L. Davies and Simon B. Blakey
Chemical Science 2013 vol. 4(Issue 6) pp:2590-2596
Publication Date(Web):19 Apr 2013
DOI:10.1039/C3SC50886B
Recently, a small number of diverse iridium complexes have been shown to catalyze unusual atom transfer C–H functionalization reactions. To further our understanding and enhance the utility of iridium complexes for C–H functionalization, we report the design and synthesis of a family of iridium(III)-bis(oxazolinyl)phenyl complexes. The ability to tune the ligand environment around the metal in these systems is exploited to design complexes with the ability to catalyze the asymmetric insertion of donor/acceptor iridium carbenoids into activated C–H bonds. Low catalyst loadings (0.5 mol%) routinely lead to excellent reaction yields (51–99%) and enantioselectivities (83–99%). Density functional theory calculations provide compelling evidence that in these complexes the carbene binds to the iridium cis to the phenyl group of the bis(oxazolinyl)phenyl ligand. This finding is vital for understanding the observed stereochemical induction and is of particular significance in the field of enantioselective transition metal-catalysed atom transfer reactions utilizing oxazoline–X–oxazoline tridentate ligands, as previously employed stereochemical models for these ligand sets are based on the assumption that reactive ligands and Lewis bases bind trans to the central X ligand.
Co-reporter:Nina Mace;Aaron R. Thornton ;Dr. Simon B. Blakey
Angewandte Chemie 2013 Volume 125( Issue 22) pp:5948-5951
Publication Date(Web):
DOI:10.1002/ange.201301087
Co-reporter:Nina Mace;Aaron R. Thornton ;Dr. Simon B. Blakey
Angewandte Chemie International Edition 2013 Volume 52( Issue 22) pp:5836-5839
Publication Date(Web):
DOI:10.1002/anie.201301087
Co-reporter:Armin H. Stoll and Simon B. Blakey
Chemical Science 2011 vol. 2(Issue 1) pp:112-116
Publication Date(Web):16 Sep 2010
DOI:10.1039/C0SC00375A
The interaction of a sulfamate ester derived metallonitrene with an allene generates a versatile intermediate with 2-amidoallylcation like reactivity. In this article we outline reactivity patterns for this novel dipolar species, demonstrating both [3 + 2] reactions with benzaldehyde, and unusual [3 + 3] annulation reactions with a variety of nitrones.
Co-reporter:Danny E. Mancheno, Aaron R. Thornton, Armin H. Stoll, Aidi Kong, and Simon B. Blakey
Organic Letters 2010 Volume 12(Issue 18) pp:4110-4113
Publication Date(Web):August 24, 2010
DOI:10.1021/ol101702w
A new catalyst system for intramolecular olefin aminoacetoxylation is described. In contrast to previously reported palladium- and copper-catalyzed systems, the conditions outlined in this communication favor piperdine formation with terminal olefin substrates and induce cyclization with traditionally less reactive disubstituted olefins.
Co-reporter:Armin H. Stoll
Journal of the American Chemical Society 2009 Volume 132(Issue 7) pp:2108-2109
Publication Date(Web):December 7, 2009
DOI:10.1021/ja908538t
The interaction of a sulfamate ester derived metallonitrene with an allene generates a versatile intermediate with 2-amidoallylcation-like reactivity, capable of rearranging to give highly substituted iminocyclopropanes or acting as a novel dipolar species engaging external dipolarophiles.
Co-reporter:Ricardo Delgado
European Journal of Organic Chemistry 2009 Volume 2009( Issue 10) pp:1506-1510
Publication Date(Web):
DOI:10.1002/ejoc.200900033
Abstract
A new cascade annulation reaction has been developed to access the core structures of a novel family of strychnos alkaloids with a unique stereochemical arrangement. The new annulation cascade is facilitated by the development of a robust reaction sequence to access extremely sensitive N-acyliminium ions. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Co-reporter:Erika Milczek;Nadège Boudet Dr. ;Simon Blakey
Angewandte Chemie International Edition 2008 Volume 47( Issue 36) pp:6825-6828
Publication Date(Web):
DOI:10.1002/anie.200801445
Co-reporter:Erika Milczek;Nadège Boudet Dr. ;Simon Blakey
Angewandte Chemie 2008 Volume 120( Issue 36) pp:6931-6934
Publication Date(Web):
DOI:10.1002/ange.200801445
Co-reporter:A. Kong, D. E. Mancheno, N. Boudet, R. Delgado, E. S. Andreansky and S. B. Blakey
Chemical Science (2010-Present) 2017 - vol. 8(Issue 1) pp:NaN700-700
Publication Date(Web):2016/09/19
DOI:10.1039/C6SC03578G
The first total synthesis of malagashanine, a chloroquine potentiating indole alkaloid, is presented. A highly stereoselective cascade annulation reaction was developed to generate the tetracyclic core of the Malagasy alkaloids. This chemistry is likely to be broadly applicable to the synthesis of other members of this stereochemically unique family of natural products.
Co-reporter:N. Mace Weldy, A. G. Schafer, C. P. Owens, C. J. Herting, A. Varela-Alvarez, S. Chen, Z. Niemeyer, D. G. Musaev, M. S. Sigman, H. M. L. Davies and S. B. Blakey
Chemical Science (2010-Present) 2016 - vol. 7(Issue 5) pp:NaN3146-3146
Publication Date(Web):2016/02/05
DOI:10.1039/C6SC00190D
The intermolecular enantioselective C–H functionalization with acceptor-only metallocarbenes is reported using a new family of Ir(III)-bis(imidazolinyl)phenyl catalysts, developed based on the interplay of experimental and computational insights. The reaction is tolerant of a variety of diazoacetate precursors and is found to be heavily influenced by the steric and electronic properties of the substrate. Phthalan and dihydrofuran derivatives are functionalized in good yields and excellent enantioselectivities.
Co-reporter:Omar Villanueva, Nina Mace Weldy, Simon B. Blakey and Cora E. MacBeth
Chemical Science (2010-Present) 2015 - vol. 6(Issue 11) pp:NaN6675-6675
Publication Date(Web):2015/07/30
DOI:10.1039/C5SC01162K
A dinuclear Co(II) complex supported by a modular, tunable redox-active ligand system is capable of selective C–H amination to form indolines from aryl azides in good yields at low (1 mol%) catalyst loading. The reaction is tolerant of medicinally relevant heterocycles, such as pyridine and indole, and can be used to form 5-, 6-, and 7-membered rings. The synthetic versatility obtained using low loadings of an earth abundant transition metal complex represents a significant advance in catalytic C–H amination technology.
Co-reporter:Clayton P. Owens, Adrián Varela-Álvarez, Vyacheslav Boyarskikh, Djamaladdin G. Musaev, Huw M. L. Davies and Simon B. Blakey
Chemical Science (2010-Present) 2013 - vol. 4(Issue 6) pp:NaN2596-2596
Publication Date(Web):2013/04/19
DOI:10.1039/C3SC50886B
Recently, a small number of diverse iridium complexes have been shown to catalyze unusual atom transfer C–H functionalization reactions. To further our understanding and enhance the utility of iridium complexes for C–H functionalization, we report the design and synthesis of a family of iridium(III)-bis(oxazolinyl)phenyl complexes. The ability to tune the ligand environment around the metal in these systems is exploited to design complexes with the ability to catalyze the asymmetric insertion of donor/acceptor iridium carbenoids into activated C–H bonds. Low catalyst loadings (0.5 mol%) routinely lead to excellent reaction yields (51–99%) and enantioselectivities (83–99%). Density functional theory calculations provide compelling evidence that in these complexes the carbene binds to the iridium cis to the phenyl group of the bis(oxazolinyl)phenyl ligand. This finding is vital for understanding the observed stereochemical induction and is of particular significance in the field of enantioselective transition metal-catalysed atom transfer reactions utilizing oxazoline–X–oxazoline tridentate ligands, as previously employed stereochemical models for these ligand sets are based on the assumption that reactive ligands and Lewis bases bind trans to the central X ligand.
Co-reporter:Armin H. Stoll and Simon B. Blakey
Chemical Science (2010-Present) 2011 - vol. 2(Issue 1) pp:NaN116-116
Publication Date(Web):2010/09/16
DOI:10.1039/C0SC00375A
The interaction of a sulfamate ester derived metallonitrene with an allene generates a versatile intermediate with 2-amidoallylcation like reactivity. In this article we outline reactivity patterns for this novel dipolar species, demonstrating both [3 + 2] reactions with benzaldehyde, and unusual [3 + 3] annulation reactions with a variety of nitrones.
Co-reporter:Andrew G. Schafer and Simon B. Blakey
Chemical Society Reviews 2015 - vol. 44(Issue 17) pp:NaN5980-5980
Publication Date(Web):2015/06/05
DOI:10.1039/C5CS00354G
Recently, several novel iridium complexes have been shown to catalyse group transfer reactions in a highly selective fashion. Rhodium complexes, and in particular dirhodium tetracarboxylate salts, have proven to be a remarkably useful class of catalysts for these reactions through several decades of development. Recent results suggest that iridium may offer opportunities to address challenges in this chemistry and provide complementary reactivity patterns. This tutorial review outlines the recent developments in Ir-catalyzed enantioselective group transfer chemistry with highlights on examples which display this unique reactivity.