Facile construction of three-membered rings via benzyne-promoted Darzens-type reaction of tertiary amines
作者:Ya-Nan Xu、Shi-Kai Tian
DOI:10.1016/j.tet.2018.11.065
日期:2019.3
A range of tertiary amines having electron-withdrawing groups were activated in situ by benzyne, generated from 2-(trimethylsilyl)phenyl triflate and a fluoride source, and participated in the Darzens-type reaction with carbonyl compounds, imines, and vinyl ketones to afford structurally diverse epoxides, aziridines, and cyclopropanes, respectively, in moderate to excellent yields with high trans-selectivity
Racemic and asymmetric cobalt-catalysed reductive aldol couplings of α,β-unsaturated amides with ketones
作者:Ralph J.R. Lumby、Pekka M. Joensuu、Hon Wai Lam
DOI:10.1016/j.tet.2008.06.022
日期:2008.8
In the presence of diethylzinc as a stoichiometric reductant, substoichiometric quantities of an appropriate cobalt source catalyse diastereoselective reductive aldol coupling reactions of α,β-unsaturatedamides with ketones. The use of a readily available oxazolidine as a chiral auxiliary imparts high levels of asymmetric induction in these reactions.
A solution of potassium tert-butoxide in THF was shown to remarkably enhance the base-induced Sommelet-Hauser rearrangement of N-benzylic amino acid-derived ammonium ylides. (C) 2010 Elsevier Ltd. All rights reserved.