Organocatalytic Stereoselective Direct Aldol Reaction of Trifluoroethyl Thioesters
作者:Sergio Rossi、Maurizio Benaglia、Franco Cozzi、Andrea Genoni、Tiziana Benincori
DOI:10.1002/adsc.201100122
日期:2011.4.18
organocatalytic, stereoselective and direct aldol reaction of activated thioesters with aldehydes has been accomplished. The trichlorosilyl ketene thioacetal generated in situ by adding a tertiary amine to a trifluoroethyl thioester in the presence of tetrachlorosilane is activated by catalytic amounts of an enantiomerically pure biheteroaromatic phosphine oxide to react with different aldehydes, coordinated
已经完成了活化的硫酯与醛的第一有机催化,立体选择性和直接的羟醛反应。通过在四氯硅烷存在下将叔胺添加到三氟乙基硫代酯中原位生成的三氯甲硅烷基烯酮硫缩醛被催化量的对映体纯的双杂芳族氧化膦与不同的醛反应活化,并与手性阳离子高价配位并被其激活硅物种。从各种容易得到的硫酯的开始,此路易斯酸介导的路易斯碱催化转换允许直接合成SYN在高达95%-β-羟基硫酯EE。