Triphenylphosphine-Catalyzed Dehydrogenative Coupling Reaction of Carboxylic Acids with Silanes – A Convenient Method for the Preparation of Silyl Esters
作者:Guo-Bin Liu、Hong-Yun Zhao、Thies Thiemann
DOI:10.1002/adsc.200600338
日期:2007.4.2
Triphenylphosphine has been found to be an efficient catalyst for the dehydrosilylation of carboxylic acids with silanes. In the presence of 4 mol % of triphenylphosphine (PPh3), dehydrosilylation reactions in DMF afforded the corresponding silyl esters at 120 °C in good yield.
Alcohols, phenols and carboxylic acids are silylated with very good yields in the presence of silyl methallylsulfinates under non-basic conditions and with the formation of volatile co-products.
Re2(CO)10 efficiently catalyzes the direct reduction of various carboxylic acids under mild conditions (rt, irradiation 350 or 395 nm). While aliphatic carboxylic acids were readily converted to the corresponding disilylacetals with low catalyst loading (0.5 mol %) in the presence of Et3SiH (2.2 equiv), aromatic analogues required more drastic conditions (Re2(CO)10 5 mol %, Ph2MeSiH 4.0 equiv) to afford