Reaction of Tantalum–Alkyne Complexes with Isocyanates or Acyl Cyanides. Stereoselective Functionalization of Carbon–Carbon Triple Bonds
作者:Yasutaka Kataoka、Yoshiyuki Oguchi、Kazuyuki Yoshizumi、Seiji Miwatashi、Kazuhiko Takai、Kiitiro Utimoto
DOI:10.1246/bcsj.65.1543
日期:1992.6
produces tantalum-alkyne complexes (not isolated), which react in situ with phenyl isocyanate (or butyl isocyanate) to give (E)-α,β-unsaturated amides stereoselectively. The tantalum–alkyne complexes also react with acyl cyanides in the presence of BF3·OEt2 to give α-cyanohydrins. In both reactions, filtration of the reaction mixture containing the tantalum–alkyne complexes before addition of isocyanates
用源自 TiCl5 和锌的低价钽处理炔烃产生钽-炔烃配合物(未分离),其与异氰酸苯酯(或异氰酸丁酯)原位反应,立体选择性地生成 (E)-α,β-不饱和酰胺。在 BF3·OEt2 存在下,钽-炔配合物也与酰基氰反应生成 α-氰醇。在这两个反应中,在加入异氰酸酯(或酰基氰化物)之前过滤含有钽-炔配合物的反应混合物对于获得良好的收率是必不可少的。