title: Cesium carbonate catalyzed chemoselective hydrosilylation of aldehydes and ketones under solvent-free conditions.
abstract: Cs2CO3 has been found to be an efficient and chemoselective catalyst for reduction of aldehydes and ketones to alcohols with one equivalent of Ph2SiH2 as the reductant under solvent-free conditions. Most of the aldehydes employed can be effectively hydrosilated quantitatively to give the corresponding silyl ethers in 2 h at room temperature, whereas the hydrosilylation of ketones proceeded smoothly at 80 °C. The catalyst system tolerates a number of functional groups including halogen, alkoxyl, olefin, ester, nitro, cyano, and heteroaromatic groups; the selective hydrosilylation of aldehydes in the presence of ketone can be effectively controlled by temperature; and hydrosilylation of α,β-unsaturated carbonyls resulted in the 1,2-addition products. The catalytic hydrosilylation of suitable dicarbonyls can be applied to the synthesis of poly(silyl ether)s with a high molecular weight and narrow molecular distribution.
authors.affiliation: State Key Laboratory of Elemento-Organic Chemistry, Nankai University, Tianjin 300071 (P. R. China), Fax: (+86) 22-23503461.
authors.forename: Mengdi
authors.initials: M
authors.lastname: Zhao
authors.forename: Weilong
authors.initials: W
authors.lastname: Xie
authors.forename: Chunming
authors.initials: C
authors.lastname: Cui
keywords: alcohols; aldehydes; cesium carbonate; hydrosilylation; ketones; silyl ethers