Chiral rhodium-bisoxazolinylphenyl acetate complexes exhibited high catalytic activity for the beta-boration of alpha,beta-unsaturatedcarbonylcompounds with bis(pinacolato)diboron in the presence of sodium t-butoxide with enantioselectivity up to 97%.
Regio‐ and Diasteroselective
<scp>
<i>C</i>
‐Silylation
</scp>
of Enolate Enabled by a
<scp>β‐Boronyl</scp>
Group
作者:Yu Liu、Miao Zhan、Pengfei Li
DOI:10.1002/cjoc.202100792
日期:2022.5
Silyl enol ethers are often obtained when the lithiumenolates are trapped with chlorosilanes. Herein, we report a general method for the regio- and diasteroselective C-silylation of enolate enabled by the β-boronyl group. The formation of five-membered chelation intermediate is key to the C-selective silylation and anti-selectivity. The operationally simple protocol provides a general and predictable
Chiral rhodium[bis(oxazolinyl)phenyl] complexes exhibited high catalytic activity for the beta-boration of alpha,beta-unsaturated esters, ketones, and amides with bis(pinacolato)diboron in the presence of sodium tertbutoxide to attain high enantioselectivity of up to 97%. The substrate scope and catalytic mechanism were discussed. (C) 2013 Elsevier Ltd. All rights reserved.
Catalytic Asymmetric Boration of Acyclic α,β-Unsaturated Esters and Nitriles