Cobalt-Catalyzed Hydrosilylation/Cyclization of 1,6-Enynes

Abstract

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.

Bulky 2,6‐Dibenzhydryl‐4‐methylaniline Derived Schiff Base Complexes of Pd(II), Cu(II) and Co(II) as Efficient Catalysts for Suzuki Coupling and Alcohol Oxidation Reactions

“…(2) and 2.271(1), 2.3523(8), 2.421(1), respectively). [28] The distance between the two copper centres in 3 is 3.540 and that between the two cobalt centres in 4 is 3.418 and these distances lie within the range reported for related chlorobridged dimeric complexes. [27,28]…”

“…The Cu‐N and Cu‐Cl distances (2.076(2), 2.000(2) and 2.2008(8), 2.2724(8), 2.678(1) Å, respectively) in 3 are comparable with those found in similar pyridylimine derived chloro‐bridged dimeric Cu(II) complexes . Similarly, the Co‐N and Co‐Cl distances (2.117(3), 2.124(3) and 2.261(1), 2.370(1), 2.399(1)Å, respectively) in 4 are comparable with those for diisopropylphenyl(pyridyl)imine derived chloro‐bridged dimeric Co(II) complex (2.109(2), 2.139(2) and 2.271(1), 2.3523(8), 2.421(1)Å, respectively) . The distance between the two copper centres in 3 is 3.540 Å and that between the two cobalt centres in 4 is 3.418 Å and these distances lie within the range reported for related chloro‐bridged dimeric complexes ,…”

Recent Advances in Hydrometallation of Alkenes and Alkynes via the First Row Transition Metal Catalysis

“…[245] In 2016, Lu and co-workers developed a cobalt-catalyzed hydrosilylation/cyclization of 1,6-enynes with a simple iminopyridine Chin. [245] In 2016, Lu and co-workers developed a cobalt-catalyzed hydrosilylation/cyclization of 1,6-enynes with a simple iminopyridine Chin.…”

Fifty Years of Hydrosilylation in Polymer Science: A Review of Current Trends of Low-Cost Transition-Metal and Metal-Free Catalysts, Non-Thermally Triggered Hydrosilylation Reactions, and Industrial Applications

“…The Ni complex exhibited high catalytic activity towards the hydrosilylation of secondary hydrosilanes with yields of up to 93% and high selectivity for mono-hydrosilylation. Lu et al reported an iminopyridine complex of cobalt dichloride as catalyst for the combined hydrosilylation and cyclization of 1,6-enynes ( Figure 13) [35]. This reaction could be scaled-up to the gram scale.…”

“…A pincer complex of the composition ( tBu P C NN iPr )CoCl2 was found to deliver highest yields with respect to the regio-and Z-selectivity after activation by NaH·BEt3. Lu et al reported an iminopyridine complex of cobalt dichloride as catalyst for the combined hydrosilylation and cyclization of 1,6-enynes ( Figure 13) [35]. This reaction could be scaled-up to the gram scale.…”