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NHC-Copper(I) Halide-Catalyzed Direct Alkynylation of Trifluoromethyl Ketones on Water

An efficient and easily scalable NHC-copper(I) halide-catalyzed addition of terminal alkynes to 1,1,1-trifluoromethyl ketones, carried out on water for the first time, is reported. A series of addition reactions were performed with as little as 0.1-2.0mol% of [(NHC)CuX] (X=Cl, Br, I, OAc, OTf) complexes, providing tertiary propargylic trifluoromethyl alcohols in high yields and with excellent chemoselectivity from a broad range of aryl- and more challenging alkyl-substituted trifluoromethyl ketones (TFMKs). DFT calculations were performed to rationalize the correlation between the yield of catalytic alkynylation and the sterics of N-heterocyclic carbenes (NHCs), expressed as buried volume (%VBur), indicating that steric effects dominate the yield of the reaction. Additional DFT calculations shed some light on the differential reactivity of [(NHC)CuX] complexes in the alkynylation of TFMKs. The first enantioselective version of a direct alkynylation in the presence of C1-symmetric NHC-copper(I) complexes is also presented

The authors are grateful to Polish Ministry of Science and Higher Education for financial support of the research (grant Iuventus Plus IP2012 064172). A.P. thanks the Spanish MINECO for project CTQ2014-59832-JIN, and L.C. funding from King Abdullah University of Science and Technology (KAUS)

Wiley

Director: Ministerio de Economía y Competitividad (Espanya)
Autor: Czerwiński, Paweł
Molga, Edyta
Cavallo, Luigi
Poater Teixidor, Albert
Michalak, Michał
Data: 1 gener 2016
Resum: An efficient and easily scalable NHC-copper(I) halide-catalyzed addition of terminal alkynes to 1,1,1-trifluoromethyl ketones, carried out on water for the first time, is reported. A series of addition reactions were performed with as little as 0.1-2.0mol% of [(NHC)CuX] (X=Cl, Br, I, OAc, OTf) complexes, providing tertiary propargylic trifluoromethyl alcohols in high yields and with excellent chemoselectivity from a broad range of aryl- and more challenging alkyl-substituted trifluoromethyl ketones (TFMKs). DFT calculations were performed to rationalize the correlation between the yield of catalytic alkynylation and the sterics of N-heterocyclic carbenes (NHCs), expressed as buried volume (%VBur), indicating that steric effects dominate the yield of the reaction. Additional DFT calculations shed some light on the differential reactivity of [(NHC)CuX] complexes in the alkynylation of TFMKs. The first enantioselective version of a direct alkynylation in the presence of C1-symmetric NHC-copper(I) complexes is also presented
The authors are grateful to Polish Ministry of Science and Higher Education for financial support of the research (grant Iuventus Plus IP2012 064172). A.P. thanks the Spanish MINECO for project CTQ2014-59832-JIN, and L.C. funding from King Abdullah University of Science and Technology (KAUS)
Format: application/pdf
Accés al document: http://hdl.handle.net/10256/13167
Llenguatge: eng
Editor: Wiley
Col·lecció: info:eu-repo/semantics/altIdentifier/doi/10.1002/chem.201601581
info:eu-repo/semantics/altIdentifier/issn/0947-6539
info:eu-repo/grantAgreement/MINECO//CTQ2014-59832-JIN/ES/ESCANEO COMPUTACIONAL DE RELACIONES ESTRUCTURA%2FACTIVIDAD DE CATALIZADORES DE OXIDACION DEL AGUA PARA LA GENERACION DE H2/
Drets: Tots els drets reservats
Matèria: Alquins
Alkynes
Coure
Copper
Cetones
Ketones
Density functionals
Funcional de densitat, Teoria del
Títol: NHC-Copper(I) Halide-Catalyzed Direct Alkynylation of Trifluoromethyl Ketones on Water
Tipus: info:eu-repo/semantics/article
Repositori: DUGiDocs

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