Enantioselective 1,4-addition of aryllithium reagents to α,β-unsaturated tert-butyl esters in the presence of chiral additives
作者:Feng Xu、Richard D. Tillyer、David M. Tschaen、Edward J.J. Grabowski、Paul J. Reider
DOI:10.1016/s0957-4166(98)00157-8
日期:1998.5
Reaction of t-BuLi with a mixture of aryl bromide and chiral diamine, amino ether or diether, in toluene at −78°C provided chiral aryllithium complexes efficiently. Reaction of these aryllithium complexes with α,β-unsaturatedtert-butylesters afforded the 1,4-addition products in up to 88% ee.
Heck reactions of aryl halides in phosphonium salt ionic liquids: library screening and applications
作者:David A. Gerritsma、Al Robertson、James McNulty、Alfredo Capretta
DOI:10.1016/j.tetlet.2004.08.103
日期:2004.10
The Heck cross-coupling of aryl iodides and bromides with olefins proceeds in the phosphonium salt ionic liquid trihexyl(tetradecyl)phosphonium chloride (THP-Cl) in excellent yields. Furthermore, it is shown that the counter anion matched to the phosphonium cation exerts a measurable effect on the overall yield. (C) 2004 Elsevier Ltd. All rights reserved.