Stereospecific asymmetric N-heterocyclic carbene (NHC)-catalyzed redox synthesis of trifluoromethyl dihydropyranones and mechanistic insights

Alyn T. Davies; James E. Taylor; James Douglas; Christopher J. Collett; Louis C. Morrill; Charlene Fallan; Alexandra M.Z. Slawin; Gwydion Churchill; Andrew D. Smith

doi:10.1021/jo401433q

Stereospecific asymmetric N-heterocyclic carbene (NHC)-catalyzed redox synthesis of trifluoromethyl dihydropyranones and mechanistic insights

Alyn T. Davies, James E. Taylor, James Douglas, Christopher J. Collett, Louis C. Morrill, Charlene Fallan, Alexandra M.Z. Slawin, Gwydion Churchill, Andrew D. Smith

Department of Chemistry

Research output: Contribution to journal › Article › peer-review

66 Citations (SciVal)

Abstract

N-Heterocyclic carbene (NHC)-catalyzed redox asymmetric hetero-Diels-Alder reactions of α-aroyloxyaldehydes with β-trifluoromethyl enones generates synthetically useful dihydropyranones containing a stereogenic trifluoromethyl substituent in good yields (up to 81%) and excellent diastereoselectivity and enantioselectivity (up to >95:5 dr and >99% ee). The process is stereospecific, with use of either (E)- or (Z)-β- trifluoromethyl enones forming syn- or anti-dihydropyranone products, respectively. Mechanistic studies through in situ kinetic analysis of the reaction reveal key differences in reactivity between chiral NHC precursor 1 and an achiral NHC precursor.

Original language	English
Pages (from-to)	9243-9257
Number of pages	15
Journal	Journal of Organic Chemistry
Volume	78
Issue number	18
Early online date	19 Aug 2013
DOIs	https://doi.org/10.1021/jo401433q
Publication status	Published - 20 Sept 2013

ASJC Scopus subject areas

Organic Chemistry

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10.1021/jo401433q

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title = "Stereospecific asymmetric N-heterocyclic carbene (NHC)-catalyzed redox synthesis of trifluoromethyl dihydropyranones and mechanistic insights",

abstract = "N-Heterocyclic carbene (NHC)-catalyzed redox asymmetric hetero-Diels-Alder reactions of α-aroyloxyaldehydes with β-trifluoromethyl enones generates synthetically useful dihydropyranones containing a stereogenic trifluoromethyl substituent in good yields (up to 81%) and excellent diastereoselectivity and enantioselectivity (up to >95:5 dr and >99% ee). The process is stereospecific, with use of either (E)- or (Z)-β- trifluoromethyl enones forming syn- or anti-dihydropyranone products, respectively. Mechanistic studies through in situ kinetic analysis of the reaction reveal key differences in reactivity between chiral NHC precursor 1 and an achiral NHC precursor.",

author = "Davies, {Alyn T.} and Taylor, {James E.} and James Douglas and Collett, {Christopher J.} and Morrill, {Louis C.} and Charlene Fallan and Slawin, {Alexandra M.Z.} and Gwydion Churchill and Smith, {Andrew D.}",

year = "2013",

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doi = "10.1021/jo401433q",

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T1 - Stereospecific asymmetric N-heterocyclic carbene (NHC)-catalyzed redox synthesis of trifluoromethyl dihydropyranones and mechanistic insights

AU - Davies, Alyn T.

AU - Taylor, James E.

AU - Douglas, James

AU - Collett, Christopher J.

AU - Morrill, Louis C.

AU - Fallan, Charlene

AU - Slawin, Alexandra M.Z.

AU - Churchill, Gwydion

AU - Smith, Andrew D.

PY - 2013/9/20

Y1 - 2013/9/20

N2 - N-Heterocyclic carbene (NHC)-catalyzed redox asymmetric hetero-Diels-Alder reactions of α-aroyloxyaldehydes with β-trifluoromethyl enones generates synthetically useful dihydropyranones containing a stereogenic trifluoromethyl substituent in good yields (up to 81%) and excellent diastereoselectivity and enantioselectivity (up to >95:5 dr and >99% ee). The process is stereospecific, with use of either (E)- or (Z)-β- trifluoromethyl enones forming syn- or anti-dihydropyranone products, respectively. Mechanistic studies through in situ kinetic analysis of the reaction reveal key differences in reactivity between chiral NHC precursor 1 and an achiral NHC precursor.

AB - N-Heterocyclic carbene (NHC)-catalyzed redox asymmetric hetero-Diels-Alder reactions of α-aroyloxyaldehydes with β-trifluoromethyl enones generates synthetically useful dihydropyranones containing a stereogenic trifluoromethyl substituent in good yields (up to 81%) and excellent diastereoselectivity and enantioselectivity (up to >95:5 dr and >99% ee). The process is stereospecific, with use of either (E)- or (Z)-β- trifluoromethyl enones forming syn- or anti-dihydropyranone products, respectively. Mechanistic studies through in situ kinetic analysis of the reaction reveal key differences in reactivity between chiral NHC precursor 1 and an achiral NHC precursor.

UR - http://www.scopus.com/inward/record.url?scp=84884579203&partnerID=8YFLogxK

U2 - 10.1021/jo401433q

DO - 10.1021/jo401433q

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SN - 0022-3263

VL - 78

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JO - Journal of Organic Chemistry

JF - Journal of Organic Chemistry

IS - 18

ER -

Stereospecific asymmetric N-heterocyclic carbene (NHC)-catalyzed redox synthesis of trifluoromethyl dihydropyranones and mechanistic insights

Abstract

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