An iminopyridine cobalt dichloride complex was synthesized and demonstrated as an effective precatalyst for hydrosilylation/cyclization of 1,6-enynes with silanes. Various functional groups such as amine, free aniline, ester, ether, cyano, halide, trifluoromethyl, and heterocycle were tolerated to afford a variety of silicon-containing compounds. The reaction could be scaled up to afford products on the gram scale which could undergo further derivatizations. A primary mechanism was proposed based on analysis of side products and a deuterated experiment.
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http://dx.doi.org/10.1021/acs.joc.6b01555 | DOI Listing |
Chem Sci
May 2023
Engineering Center of Catalysis and Synthesis for Chiral Molecules, Fudan University 200433 Shanghai China
Spirodiphosphines have been successfully applied in various asymmetric catalytic transformations. However, controlling the coordinating conformations by the direct displacement of the spiro atom remains elusive. Herein, we report the application of Si-centered spirodiphosphine (Si-SDP) ligands in the enantioselective hydrosilylation/cyclization of 1,6-enynes.
View Article and Find Full Text PDFOrg Biomol Chem
November 2022
College of Chemical Engineering, Zhejiang University of Technology, Hangzhou, 310014, China.
We herein describe a nickel-catalyzed cascade hydrosilylation/cyclization reaction of 1,7-enynes with bulky triphenylsilane. A series of silyl-containing quinolinone derivatives are obtained in good to excellent yields under mild reaction conditions. This reaction also features excellent chemoselectivity, broad functional group tolerance, and gram-scale synthesis.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
May 2021
Department of Chemistry, National University of Singapore, 3 Science Drive 3, 117543, Singapore, Singapore.
We report an enantioselective cobalt-catalyzed hydrosilylation/cyclization reaction of 1,6-enynes with secondary and tertiary hydrosilanes employing a catalyst generated in situ from the combination of Co(acac) and (R,S )-Josiphos. A wide range of oxygen-, nitrogen-, and carbon-tethered 1,6-enynes reacted with Ph SiH , (EtO) SiH, or (RO) MeSiH to afford the corresponding chiral organosilane products in high yields and up to >99 % ee. This cobalt-catalyzed hydrosilylation/cyclization also occurred with prochiral secondary hydrosilane PhMeSiH to yield chiral alkylsilanes containing both carbon- and silicon-stereogenic centers with excellent enantioselectivity, albeit with modest diastereoselectivity.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
April 2019
Department of Chemistry, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama, 223-8522, Japan.
Sequential formation of distant bonds in organic molecules was achieved for the palladium-catalyzed hydrosilylation/cyclization of various 1,n-dienes by chain walking of the metal catalyst. The reaction was applicable to various 1,n-dienes, including a 1,13-diene, to form a cyclopentane ring as well as a carbon-silicon bond at a remote site. The use of "nondissociative" chain walking provides a fascinating strategy in organic synthesis to functionalize distant parts of organic molecules, in a particular order, within a catalytic cycle by effectively moving the reactive center from a remote position.
View Article and Find Full Text PDFJ Org Chem
October 2016
Department of Chemistry, Zhejiang University, 866 Yuhangtang Road, Hangzhou 310058, China.
An iminopyridine cobalt dichloride complex was synthesized and demonstrated as an effective precatalyst for hydrosilylation/cyclization of 1,6-enynes with silanes. Various functional groups such as amine, free aniline, ester, ether, cyano, halide, trifluoromethyl, and heterocycle were tolerated to afford a variety of silicon-containing compounds. The reaction could be scaled up to afford products on the gram scale which could undergo further derivatizations.
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