using a combination of hypervalent iodine(III) reagent, molecular iodine, and a base. This method offers an efficient synthesis of 2-acyl furans with diverse substitutionpatterns in a regioselective manner under mildreaction conditions. A mechanistic proposal for these transformations involving alkyne activation by trifluoroacetylhypoiodite generated in situ is presented.
Aldol reaction of allenolates generated via 1,4-addition of iodide anion or its equivalent to α,β-acetylenic ketones
作者:Mikio Taniguchi、Tohru Hino、Yoshito Kishi
DOI:10.1016/s0040-4039(00)85060-1
日期:——
TMSI, Et2AlI and (n-Bu)4NI/TiCl4 smoothly added to α,β-acetylenicketones in a 1,4-fashion to yield allenolates , which reacted with aldehydes providing aldol adducts in good overall yield. A high Z-stereoselectivity was achieved by use of (n-Bu)4NI/TiCl4 at −78°C, while a high E-stereoselectivity occurred at 0°C.
将TMSI,Et 2 AlI和(n-Bu)4 NI / TiCl 4平稳地以1,4-方式添加到α,β-炔酮中以生成烯丙基酯,该烯丙基酯与醛反应生成醛醇加合物,总收率良好。通过在-78°C下使用(n-Bu)4 NI / TiCl 4可以实现高Z-立体选择性,而在0°C时则可以实现高E-立体选择性。