Feeding the Heck Reaction with Alcohol: One-Pot Synthesis of Stilbenes from Aryl Alcohols and Bromides
作者:Paul Colbon、Jonathan H. Barnard、Mark Purdie、Keith Mulholland、Ivan Kozhevnikov、Jianliang Xiao
DOI:10.1002/adsc.201200340
日期:2012.5.21
Aryl alcohols are employed as feedstock for the Heck reaction. Keggin‐type heteropolyacids catalyse the selective dehydration of the alcohols to styrenes, which, in one‐pot, undergo palladium‐catalysed Heck arylation with aryl bromides, affording broadly functionalised stilbenes. The choice of solvent is critical for the cascade dehydration–Heck reaction, with electron‐rich aryl alcohols preferring
Chiral spiroaminoborate ester as a highly enantioselective and efficient catalyst for the borane reduction of furyl, thiophene, chroman, and thiochroman-containing ketones
作者:Viatcheslav Stepanenko、Melvin De Jesús、Wildeliz Correa、Lorianne Bermúdez、Cindybeth Vázquez、Irisbel Guzmán、Margarita Ortiz-Marciales
DOI:10.1016/j.tetasy.2009.11.009
日期:2009.12
Prochiral heteroaryl ketones containing furan, thiophene, chroman, and thiochroman moieties were successfully reduced in the presence of 1-10 mol% of spiroaminoborate ester 1 with different borane sources to afford non-racemic alcohols in up to 99% ee. In addition, modest enantioselectivity, around 80% ee, was achieved in the reduction of linear alpha,beta-unsaturated heteroaryl ketones. (C) 2009 Elsevier Ltd. All rights reserved.