Tris(2,4,6-trimethoxyphenyl)phosphine:: Base catalyst in the transformation of α,β unsaturated aldehydes to saturated carboxylic-acid derivatives

We have focused on the basicity of Tris(2,4,6-trimethoxyphenyl)phosphine (YTMPP) in organic synthesis. To extend the utility of TTMPP, we examined the reaction of alpha, beta-unsaturated aldehydes with trimethylsilyl cyanide in the presence of YTMPR Furthermore, to clarify the basic character of 7TMPP, we measured P-31 NMR of TTMPP and related compounds. First, the reaction of cinnamaldehydes with trimethylsilyl cyanide in the presence of a catalytic amount of TTMPP afforded the corresponding saturated carboxylic acids after hydrolysis with 1M HCl. Treatment of the reaction mixture with alcohols or amines instead of 1M HCl gave the cor, responding saturated esters and amides, respectively. As a result of studies of the reaction mechanism, it was revealed that the reaction proceeded via silylcyanation of alpha, beta-unsaturated aldehydes with trimethylsilyl cyanide to produce trimethylsilyl ethers of cyanohydrin and subsequent isomerization that formed alpha-trimethylsiloxy vinyl cyanides, which were hydrolyzed to give saturated carboxylic acids.