Jin Kun Cha

Find an error

Name: Cha, Jin K; Jin Kun Cha

Organization: Wayne State University , USA

Department: Department of Chemistry

Title: Professor(PhD)

TOPICS

Organic Chemistry

Polymer

Stimuli Responsive Polymers PH Responsive Polymers Stimuli Responsive Polymers PH Responsive Polymers Temperature Responsive Polymers

Chemicals
References

Cu-Mediated Rearrangements of Allenylcyclopropanols to Cyclopentenones: Two Divergent Pathways

Co-reporter:Naresh Tumma, Eppa Gyanchander, and Jin Kun Cha

The Journal of Organic Chemistry April 21, 2017 Volume 82(Issue 8) pp:4379-4379

Publication Date(Web):March 24, 2017

DOI:10.1021/acs.joc.7b00432

Two CuCN-mediated rearrangement reactions of allenylcyclopropanols to cyclopentenones have been achieved by means of Et2Zn/CuCN·2LiCl or CuCN·2LiCl to afford 5-alkyl or 4-alkyl cyclopentenone regioisomers: the former conditions afford 5-alkyl substituted cyclopentenones via β-carbon elimination, whereas the latter result in the 4-alkyl substituted regioisomers with concomitant oxidation at the γ-position, via a free radical mechanism.

Mechanism of Ru(II)-Catalyzed Rearrangements of Allenyl- and Alkynylcyclopropanols to Cyclopentenones

Co-reporter:Eppa Gyanchander, Sridhar Ydhyam, Naresh Tumma, Ken Belmore, and Jin Kun Cha

Organic Letters 2016 Volume 18(Issue 23) pp:6098-6101

Publication Date(Web):November 10, 2016

DOI:10.1021/acs.orglett.6b03088

A comparison study of the Ru(II)-catalyzed rearrangements of allenyl- and alkynylcyclopropanols to the corresponding cyclopentenones has been undertaken with the aid of an alkyl substituent on the three-membered ring. These ring expansion reactions proceed with exceptional regioselectivity irrespective of the cis/trans stereochemistry of the substituents on the three-membered ring. β-Carbon elimination is the common feature in the absence of a chelating group at the 4′-position in the alkyne chain.

Concise Synthesis of Alkaloid (−)-205B

Co-reporter:Nagavaram Narsimha Rao

Journal of the American Chemical Society 2015 Volume 137(Issue 6) pp:2243-2246

Publication Date(Web):January 30, 2015

DOI:10.1021/jacs.5b00243

Described herein is a short total synthesis of alkaloid (−)-205B (1) by means of an anti-selective SN2′ alkylation of an attractively functionalized cyclopropanol and diastereoselective cyclization of the resulting aminoallene adduct for bicyclic ring formation. The synthesis features a general route to cis- or trans-2,6-disubstituted piperidines by lithium aluminum hydride reduction of the imine intermediate by an appropriate choice of solvent and cis- or trans-2,5-disubstituted pyrrolidines by an exceptional level of chirality transfer from a pendant allene. Particularly noteworthy are the brevity and convergence made possible by a segment-coupling strategy.

Construction of Seven-Membered Carbocycles via Cyclopropanols

Co-reporter:Sridhar Ydhyam and Jin Kun Cha

Organic Letters 2015 Volume 17(Issue 23) pp:5820-5823

Publication Date(Web):November 17, 2015

DOI:10.1021/acs.orglett.5b02978

A new method for seven-membered ring annulation has been devised by an intramolecular cross-coupling of cyclopropanols and aryl/alkenyl halides. This cyclization reaction is broad in scope and provides easy access to not only fused but also bridged bicyclic compounds.

C-Alkynylation of Cyclopropanols

Co-reporter:R. V. N. S. Murali, Nagavaram Narsimha Rao, and Jin Kun Cha

Organic Letters 2015 Volume 17(Issue 15) pp:3854-3856

Publication Date(Web):July 22, 2015

DOI:10.1021/acs.orglett.5b01789

Alkynylation of cyclopropanols with 1-bromo-1-alkynes has been devised for easy access to synthetically useful alk-4-yn-1-ones. This method broadens the utility of attractively functionalized cyclopropanols as a new class of homoenolate equivalent in C–C bond formation.

Alkoxy-directed cyclopropanation of 1,1-disubstituted alkenes with esters: new approach to quaternary carbon centers

Co-reporter:Nagavaram Narsimha Rao, Jin Kun Cha

Tetrahedron Letters 2015 Volume 56(Issue 23) pp:3298-3300

Publication Date(Web):3 June 2015

DOI:10.1016/j.tetlet.2014.12.043

As a new approach to the stereocontrolled construction of quaternary centers, 1,2,2-trisubstituted cyclopropanols are prepared by the olefin exchange-mediated Kulinkovich cyclopropanation of esters with 1,1-disubstituted alkenes bearing homoallylic alcohols. Central to the successful cyclopropanation is the generation of a temporary alkoxy tether from a homoallylic alcohol.

Cross-Coupling of Cyclopropanols: Concise Syntheses of Indolizidine 223AB and Congeners

Co-reporter:Nagavaram Narsimha Rao, Bibhuti Bhusan Parida, and Jin Kun Cha

Organic Letters 2014 Volume 16(Issue 23) pp:6208-6211

Publication Date(Web):November 25, 2014

DOI:10.1021/ol503136s

A new synthetic method for indolizidine or pyrrolizidine alkaloids based on readily available and attractively functionalized cyclopropanols, as exemplified in concise syntheses of indolizidine (−)-223AB, its 3-epimer, (−)-indolizidine 239AB, and (−)-indolizidine 239CD, is reported. This work highlights the applications of SN2′ alkylation and C-acylation of cyclopropanols to meet stereochemical challenges in natural product synthesis. Also included is diastereoselective cyclization of the resulting aminoallene adduct for bicyclic ring formation.

Hydroxy-Directed Cyclopropanation of Esters: Synthesis of Trisubstituted Cyclopropanols

Co-reporter:Dmitry Astashko, ;Nagavaram Narsimha Rao ;Bibhuti Bhusan Parida

European Journal of Organic Chemistry 2014 Volume 2014( Issue 1) pp:181-187

Publication Date(Web):

DOI:10.1002/ejoc.201301252

Abstract

The Kulinkovich cyclopropanation of esters with disubstituted homoallylic alcohols is described for the preparation of 1,2,3-trisubstituted cyclopropanols. Central to the successful implementation is the generation in situ of a temporary alkoxy tether between a homoallylic alcohol and an alkoxytitanium species to override unfavorable steric factors.

C-Acylation of Cyclopropanols: Preparation of Functionalized 1,4-Diketones

Co-reporter:Bibhuti Bhusan Parida, Pragna Pratic Das, Mathilde Niocel, and Jin Kun Cha

Organic Letters 2013 Volume 15(Issue 7) pp:1780-1783

Publication Date(Web):March 25, 2013

DOI:10.1021/ol400666x

A convenient method for preparing attractively functionalized 1,4-diketones has been devised by palladium-catalyzed cross-coupling of cyclopropanols and acyl chlorides. The utility of this method has been demonstrated in an enantioselective synthesis of (+)-myrmicarin 217.

Stereoselective Synthesis of 2,6-trans-Tetrahydropyrans

Co-reporter:Bibhuti Bhusan Parida, Ivan L. Lysenko, and Jin Kun Cha

Organic Letters 2012 Volume 14(Issue 24) pp:6258-6261

Publication Date(Web):December 10, 2012

DOI:10.1021/ol3030204

A stereoselective route to the thermodynamically unfavorable 2,6-trans-tetrahydropyrans has been developed from coupling of hydroxyethyl-tethered cyclopropanols and aliphatic aldehydes. Noteworthy is high convergency from direct coupling of two segments.

SN2 Alkylation of Cyclopropanols via Homoenolates

Co-reporter:Dr. Pragna Pratic Das;Dr. Ken Belmore;Dr. Jin Kun Cha

Angewandte Chemie International Edition 2012 Volume 51( Issue 38) pp:9517-9520

Publication Date(Web):

DOI:10.1002/anie.201205190

SN2 Alkylation of Cyclopropanols via Homoenolates

Co-reporter:Dr. Pragna Pratic Das;Dr. Ken Belmore;Dr. Jin Kun Cha

Angewandte Chemie 2012 Volume 124( Issue 38) pp:9655-9658

Publication Date(Web):

DOI:10.1002/ange.201205190

Stereoselective Alkylation of Allylic Alcohols: Tandem Ethylation and Functionalization

Co-reporter:Dr. Pragna Pratic Das;Dr. Ivan L. Lysenko ;Dr. Jin Kun Cha

Angewandte Chemie 2011 Volume 123( Issue 40) pp:9631-9633

Publication Date(Web):

DOI:10.1002/ange.201104331

Stereoselective Alkylation of Allylic Alcohols: Tandem Ethylation and Functionalization

Co-reporter:Dr. Pragna Pratic Das;Dr. Ivan L. Lysenko ;Dr. Jin Kun Cha

Angewandte Chemie International Edition 2011 Volume 50( Issue 40) pp:9459-9461

Publication Date(Web):

DOI:10.1002/anie.201104331

Total Synthesis of Pareitropone via Radical Anion Coupling

Co-reporter:Suk-Koo Hong, Hyeonjeong Kim, Youngran Seo, Sang Hyup Lee, Jin Kun Cha and Young Gyu Kim

Organic Letters 2010 Volume 12(Issue 17) pp:3954-3956

Publication Date(Web):August 10, 2010

DOI:10.1021/ol1017849

A concise (9-step) synthesis of the tropoloisoquinoline alkaloid pareitropone has been achieved starting from 2-bromoisovanillin. The key step features oxidative cyclization of a readily available phenolic nitronate for the convenient construction of the fused tropone ring. This work underscores the synthetic utility of intramolecular oxidative coupling reactions of phenolic nitronates.

Cross-coupling of homoallylic alcohols with styrene

Co-reporter:Madhesan Balakrishnan, Jin Kun Cha

Tetrahedron Letters 2010 Volume 51(Issue 42) pp:5571-5573

Publication Date(Web):20 October 2010

DOI:10.1016/j.tetlet.2010.08.054

A cross-coupling reaction between a homoallylic alcohol and styrene is described to broaden the scope of the titanium alkoxide tether-mediated coupling reactions. Particularly noteworthy is exceptional 1,3-diastereoselectivity by o-vinylanisole in coupling with a Z-homoallylic alcohol.

Stereoselective Cross-Coupling between Allylic Alcohols and Aldimines

Co-reporter:Ivan L. Lysenko, Hyung Goo Lee and Jin Kun Cha

Organic Letters 2009 Volume 11(Issue 14) pp:3132-3134

Publication Date(Web):June 24, 2009

DOI:10.1021/ol901006c

A cross-coupling reaction between an allylic alcohol and an imine is described for stereoselective allylation of aromatic and aliphatic imines. This method provides operationally simple, enantioselective access to functionalized homoallylic amines. Particularly noteworthy is direct use of a functionalized allylic alcohol as an allylating reagent without prederivatization, which obviates the use of preformed organometallic reagents or activated imine derivatives.

Total Synthesis of CyathinA3 and CyathinB2

Co-reporter:Keunho Kim ;JinKun Cha Dr.

Angewandte Chemie International Edition 2009 Volume 48( Issue 29) pp:5334-5336

Publication Date(Web):

DOI:10.1002/anie.200901669

Total Synthesis of CyathinA3 and CyathinB2

Co-reporter:Keunho Kim ;JinKun Cha Dr.

Angewandte Chemie 2009 Volume 121( Issue 29) pp:5438-5440

Publication Date(Web):

DOI:10.1002/ange.200901669

Stereoselective Synthesis of 2,4,6-Trisubstituted Tetrahydropyrans by the Use of Cyclopropanols as Homoenols

Co-reporter:Hyung Goo Lee Dr.;Ivan L. Lysenko Dr.;Jin Kun Cha

Angewandte Chemie International Edition 2007 Volume 46(Issue 18) pp:

Publication Date(Web):27 MAR 2007

DOI:10.1002/anie.200700172

A convenient method for preparing all-cis 2,4,6-trisubstituted tetrahydropyrans and the corresponding 2,6-trans isomers has been developed. This trimethylsilyl triflate mediated coupling of cyclopropanols with a 2-hydroxyalkyl side chain to aldehydes (see scheme) is also suitable for the coupling of two large subunits to generate structural complexity in a rapid and highly convergent manner.

Stereoselective Synthesis of 2,4,6-Trisubstituted Tetrahydropyrans by the Use of Cyclopropanols as Homoenols

Co-reporter:Hyung Goo Lee Dr.;Ivan L. Lysenko Dr.;Jin Kun Cha

Angewandte Chemie 2007 Volume 119(Issue 18) pp:

Publication Date(Web):27 MAR 2007

DOI:10.1002/ange.200700172

Eine praktische Methode für die Synthese von all-cis-2,4,6-trisubstituierten Tetrahydropyranen und den entsprechenden 2,6-trans-Isomeren wurde entwickelt. Diese durch Trimethylsilyltriflat vermittelte Kupplung von Cyclopropanolen mit einer 2-Hydroxyalkyl-Seitenkette an Aldehyde (siehe Schema) eignet sich auch für die Vereinigung großer Untereinheiten, was einen raschen und hoch konvergenten Weg zu komplexen Strukturen eröffnet.

Formation of Seven-Membered Carbocycles by the Use of Cyclopropyl Silyl Ethers as Homoenols

Co-reporter:Oleg L. Epstein Dr.;Sejin Lee Dr.

Angewandte Chemie 2006 Volume 118(Issue 30) pp:

Publication Date(Web):3 JUL 2006

DOI:10.1002/ange.200601011

Einfacher Ringschluss: Einen schnellen Zugang zu siebengliedrigen Carbocyclen bietet die Kulinkovich-Cyclopropanierung von Estern mit Acetaleinheit mit anschließender Addition des Cyclopropylsilylethers an das intermediäre Oxocarbeniumion. Besonders bemerkenswert ist der effektive Einsatz einer tert-Butylsilylengruppe für die diastereoselektive Cyclisierung.

Formation of Seven-Membered Carbocycles by the Use of Cyclopropyl Silyl Ethers as Homoenols

Co-reporter:Oleg L. Epstein Dr.;Sejin Lee Dr.

Angewandte Chemie International Edition 2006 Volume 45(Issue 30) pp:

Publication Date(Web):3 JUL 2006

DOI:10.1002/anie.200601011

Straightforward ring-closure: An expedient entry to seven-membered carbocycles is achieved by the Kulinkovich cyclopropanation of acetal-tethered esters and the subsequent addition of the resulting cyclopropyl silyl ethers to the oxocarbenium ion intermediates. Of particular note is the effective use of a tert-butylsilylene group for diastereoselective cyclization.

Rapid Access to the “in,out”-Tetracyclic Core of Ingenol

Co-reporter:Oleg L. Epstein Dr.

Angewandte Chemie International Edition 2005 Volume 44(Issue 1) pp:

Publication Date(Web):15 DEC 2004

DOI:10.1002/anie.200461807

In … out … shake it all about! The tetracyclic core of ingenol has been prepared in a convergent synthesis. The pinacol-type rearrangement of an epoxy alcohol provides a simple, expedient solution to the challenging “inside–outside” intrabridgehead stereochemistry of ingenol (see scheme, TBS=tert-butyldimethylsilyl).

Rapid Access to the “in,out”-Tetracyclic Core of Ingenol

Co-reporter:Oleg L. Epstein Dr.

Angewandte Chemie 2005 Volume 117(Issue 1) pp:

Publication Date(Web):15 DEC 2004

DOI:10.1002/ange.200461807

Eine konvergente Synthese des tetracyclischen Gerüsts von Ingenol wird beschrieben. Die Pinakol-Umlagerung eines Epoxyalkohols bietet eine einfache und zweckmäßige Lösung für die Einführung der „Innen-außen“-Intrabrückenkopf-Stereochemie von Ingenol (siehe Schema, TBS=tert-Butyldimethylsilyl).

Recent advances in the stereoselective synthesis of isoprostanes and neuroprostanes

Co-reporter:Long Guo Quan, Jin Kun Cha

Chemistry and Physics of Lipids 2004 Volume 128(1–2) pp:3-14

Publication Date(Web):March 2004

DOI:10.1016/j.chemphyslip.2003.10.005

This review delineates several reported methods for the synthesis of isoprostanes and neuroprostanes with particular emphasis on the stereocontrolled construction of a suitably functionalized cyclopentane core. The α- and ω-side chains of these PG-like molecules are typically assembled by Wittig-type olefination reactions, standard transformations in the PG synthesis. The synthetic strategies include free radical cyclizations, a palladium-promoted coupling of three different components, an intramolecular cyclopropanation reaction-ring-opening sequence, a [2+2] photocycloaddition-ring-opening metathesis approach, and an intramolecular cross-coupling reaction of an alkyl iodide and a tethered alkenylsiloxane.

Radical cyclization–fragmentation of ω-haloalkyl cyclobutanones: a modular approach to medium-sized carbocycles

Co-reporter:Heong-Sub Oh, Jin Kun Cha

Tetrahedron: Asymmetry 2003 Volume 14(Issue 19) pp:2911-2917

Publication Date(Web):3 October 2003

DOI:10.1016/j.tetasy.2003.07.011

A facile radical cyclization–fragmentation sequence of ω-haloalkyl-tethered spirocyclobutanones, which are readily available by the Kulinkovich cyclopropanation of cycloalkene carboxylates and subsequent electrophilic addition to haloalkyl acetals, provides a convenient method for appending seven- and eight-membered rings onto cycloalkene carboxylates. An enantioselective preparation of a medium-sized carbocycle is possible by the use of a non-racemic, C2-symmetric acetal.Graphic13-Oxatricyclo[8.2.1.02,7]tridecan-10-olC12H20O2E.e.=99%[α]D=−8.3 (c 0.004, CHCl3)Source of chirality: (R,R)-(+)-hydrobenzoinAbsolute configuration: not determined

On the Mechanism of the Anionic Oxy-Cope Rearrangement of trans-1,2-Dialkenylcyclobutanols

Co-reporter:Philippe Maurin Dr.;Se-Ho Kim;Sung Yun Cho

Angewandte Chemie International Edition 2003 Volume 42(Issue 41) pp:

Publication Date(Web):22 OCT 2003

DOI:10.1002/anie.200350988

A concerted mechanism involving a chairlike transition state (see scheme) and no appreciable loss of enantiopurity was concluded for the anionic oxy-Cope rearrangement of sterically unencumbered trans-1,2-dialkenylcyclobutanols from a study employing nonracemic substrates containing vinyl and propenyl groups with evaluation of the enantio- and diastereofacial selectivity.

On the Mechanism of the Anionic Oxy-Cope Rearrangement of trans-1,2-Dialkenylcyclobutanols

Co-reporter:Philippe Maurin Dr.;Se-Ho Kim;Sung Yun Cho

Angewandte Chemie 2003 Volume 115(Issue 41) pp:

Publication Date(Web):22 OCT 2003

DOI:10.1002/ange.200350988

Ein konzertierter Mechanismus mit einem Übergangszustand in Sesselkonformation (siehe Schema) sorgt dafür, dass die Enantiomerenreinheit bei der anionischen Oxy-Cope-Umlagerung sterisch befrachteter trans-1,2-Dialkenylcyclobutanole weitgehend erhalten bleibt. Bei dieser Untersuchung zur enantio- und diastereofacialen Selektivität wurden Substrate mit Vinyl- und Propenylsubstituenten eingesetzt.