Cyanide ion cocatalysis in Ti(salen) catalysed asymmetric cyanohydrin carbonate synthesis
作者:Yuri N. Belokon、Eisuke Ishibashi、Hiroshi Nomura、Michael North
DOI:10.1039/b602156e
日期:——
cocatalyst, 1-2 mol% of titanium(salen) complex catalyses the asymmetric addition of achiral cyanoformates to aldehydes, giving cyanohydrin carbonates with high enantiomeric excesses; and catalyses the diastereoselective addition of chiral cyanoformates derived from alpha-methylbenzyl alcohol to aldehydes, a reaction which exhibits double asymmetric induction.
Enantioselective and diastereoselective syntheses of cyanohydrin carbonates
作者:Yuri N. Belokon'、William Clegg、Ross W. Harrington、Eisuke Ishibashi、Hiroshi Nomura、Michael North
DOI:10.1016/j.tet.2007.07.016
日期:2007.9
cocatalyst are developed. Under these conditions, two chiral cyanoformates also reacted with aldehydes to give cyanohydrin carbonates. The stereochemistry of this process is predominantly determined by the stereochemistry of the titanium(salen) catalyst and the stereochemistry of two of the cyanohydrin carbonates was confirmed by X-ray crystallography. In a further extension of the chemistry, a homogeneous