nitriles is described, which gives direct access to alpha-hydroxylated and alpha-aminated ketones. This coupling reaction is cross-selective and a catalytic version of the classical acyloincondensation. A reaction mechanism that is supported by first DFT calculations is discussed.
Mechanism of the Ti<sup>III</sup>-Catalyzed Acyloin-Type Umpolung: A Catalyst-Controlled Radical Reaction
作者:Jan Streuff、Markus Feurer、Georg Frey、Alberto Steffani、Sylwia Kacprzak、Jens Weweler、Leonardus H. Leijendekker、Daniel Kratzert、Dietmar A. Plattner
DOI:10.1021/jacs.5b09223
日期:2015.11.18
titanium(III) species. The resting state is identified as a cationic titanocene-nitrile complex and the beneficial effect of added Et3N·HCl on yield and enantioselectivity is elucidated: chloride coordination initiates the radical coupling. The results are fundamental for the understanding of titanium(III)-catalysis and of relevance for other metal-catalyzed radical reactions. Our conclusions might apply