Cyclic (Alkyl)(amino)carbene Ligands Enable Cu‐Catalyzed Markovnikov Protoboration and Protosilylation of Terminal Alkynes: A Versatile Portal to Functionalized Alkenes**
Year: 2021
Type: article
Abstract: Regioselective hydrofunctionalization of alkynes represents a straightforward route to access alkenyl boronate and silane building blocks. In previously reported catalytic systems, high selectivity is achieved with a limited scope of substrates and/or reagents, with general solutions lacking. Herein, we describe a selective copper-catalyzed Markovnikov hydrofunctionalization of terminal alkynes that is facilitated by strongly donating cyclic (alkyl)(amino)carbene (CAAC) ligands. Using this method, both alkyl- and aryl-substituted alkynes are coupled with a variety of boryl and silyl reagents with high α-selectivity. The reaction is scalable, and the products are versatile intermediates that can participate in various downstream transformations. Preliminary mechanistic experiments shed light on the role of CAAC ligands in this process.
Authors: Yang Gao, Sima Yazdani, Aaron Kendrick, Glen P. Junor, Taeho Kang, Douglas B. Grotjahn, Guy Bertrand, Rodolphe Jazzar, Keary M. Engle
Language: English
Topic: Catalytic Alkyne Reactions
Subfield: Organic Chemistry
Field: Chemistry
Domain: Physical Sciences
Open Access status: green
Funders: National Science Foundation, U.S. Department of Energy, W. M. Keck Foundation, San Diego State University, Agence Nationale de la Recherche, Kwanjeong Educational Foundation, National Institutes of Health, Office of Science, American Chemical Society Petroleum Research Fund, National Institute of General Medical Sciences, Division of Chemistry, Basic Energy Sciences
Awards: Graduate Research Fellowship Program (GRFP), Chiral Cyclic Alkyl Amino Carbenes in Asymmetric Catalysis, Experimental and Computational Studies of Bifunctional Organometallic Catalysis, G3010527862, G321498615, G3377762843, Combinatorial, Catalytic Functionalization of Alkenes and Alkynes, G5036678674, AMMONIA AND HYDRAZINE: TRANSITION-METAL-CATALYZED HYDROAMINATION AND METAL-FREE CATALYZED FUNCTIONALIZATION, AMMONIA AND HYDRAZINE: TRANSITION-METAL-CATALYZED HYDROAMINATION AND METAL-FREE CATALYZED FUNCTIONALIZATION, G8352801223
OpenAlex ID: W3156532681