Cathodic Intra- and Intermolecular Couplings of Ketones with Unsaturated Silanes
摘要:
The electroreduction of 6-trimethylsilyl-6-hepten-2-one afforded cis-1-methyl-3-trimethylsilyl cyclohexanol, and gamma-trimethylsilyl alcohols were yielded as the intermolecular coupling products when the cathodic reduction of ketones was carried out in the presence of unsaturated silanes.
Biphilic Organophosphorus Catalysis: Regioselective Reductive Transposition of Allylic Bromides via P<sup>III</sup>/P<sup>V</sup>Redox Cycling
作者:Kyle D. Reichl、Nicole L. Dunn、Nicholas J. Fastuca、Alexander T. Radosevich
DOI:10.1021/jacs.5b01899
日期:2015.4.29
We report that a regioselective reductive transposition of primary allylic bromides is catalyzed by a biphilic organophosphorus (phosphetane) catalyst. Spectroscopic, evidence supports the formation of a penta:coordinate (sigma(5)-P) hydridophosphorane as a key reactive intermediate. Kinetics experiments and computational modeling are consistent with a unimolecular docomposition of the sigma(5)-P hydridophosphorane via a conceited cyclic transition,structure that delivers the observed allylic transposition and completes a novel P-III/P-V redox Catalytic cycle. These results broaden the growing repertoire., of reactions catalyzed within the P-III/P-V redox couple and suggest additional opportunities for organophosphorus,catalysis in a biphilic mode.
[.beta.-(Trimethylsilyl)ethyl]lithium: a new reagent for carbonyl reductive vinylation