NHC-Copper(I) Halide-Catalyzed Direct Alkynylation of Trifluoromethyl Ketones on Water
MetadataShow full item record
AbstractAn 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. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
CitationCzerwiński P, Molga E, Cavallo L, Poater A, Michalak M (2016) NHC-Copper(I) Halide-Catalyzed Direct Alkynylation of Trifluoromethyl Ketones on Water. Chem Eur J 22: 8089–8094. Available: http://dx.doi.org/10.1002/chem.201601581.
SponsorsThe 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 (KAUST). We would like to thank Prof. Samir Zard (Ecole Polytechnique) for helpful discussion concerning the synthesis of trifluoromethyl ketones and Dr. P. Kwiatkowski and Dr. W. Chaladaj for a generous gift of samples of trifluoromethyl ketones and alkynes.
JournalChemistry - A European Journal
- Catalytic Enantioselective Conjugate Alkynylation of α,β-Unsaturated 1,1,1-Trifluoromethyl Ketones with Terminal Alkynes.
- Authors: Sanz-Marco A, Blay G, Muñoz MC, Pedro JR
- Issue date: 2016 Jul 11
- Copper(I) alkoxide-catalyzed alkynylation of trifluoromethyl ketones.
- Authors: Motoki R, Kanai M, Shibasaki M
- Issue date: 2007 Aug 2
- Highly convenient amine-free sonogashira coupling in air in a polar mixed aqueous medium by trans- and cis-[(NHC)2PdX2] (X=Cl, Br) complexes of N/O-functionalized N-heterocyclic carbenes.
- Authors: Ray L, Barman S, Shaikh MM, Ghosh P
- Issue date: 2008
- [(NHC)CuX] complexes: synthesis, characterization and catalytic activities in reduction reactions and Click chemistry. On the advantage of using well-defined catalytic systems.
- Authors: Díez-González S, Escudero-Adán EC, Benet-Buchholz J, Stevens ED, Slawin AM, Nolan SP
- Issue date: 2010 Aug 28
- Copper/Guanidine-Catalyzed Asymmetric Alkynylation of Isatins.
- Authors: Chen Q, Tang Y, Huang T, Liu X, Lin L, Feng X
- Issue date: 2016 Apr 18