Stereoselectivity in the Wittig reaction of phenyl 3-pyridyl ketones: Amide substituent effect on the preferential (E)-ollefin formation
作者:Kumiko Takeuchi、Todd J. Kohn
DOI:10.1016/s0040-4039(98)01194-0
日期:1998.8
A Wittig reaction of amide substituted phenyl 3-pyridyl ketones with “nonstabilized” phosphorus ylides which contain a carboxyl terminus preferentially forms (E)-olefin. The preference for this stereoselectivity stems from either hydrogen bonding or salt-bridge formation between the amide group and the carboxyl terminus during the oxaphosphetane intermediate formation.
酰胺取代的苯基3-吡啶基酮与含有羧基末端的“不稳定的”磷酰化物的维蒂希反应优选形成(E)-烯烃。对于这种立体选择性的偏爱是由于在氧杂膦烷中间体的形成过程中,酰胺基团与羧基末端之间的氢键键合或盐桥形成。