>90% ee at −20 °C or at room temperature in THF. The mechanism of this process was investigated by 31P NMR spectroscopic analysis. The phenoxide or the key enolate intermediate, which is stabilized by intramolecular hydrogen bonding with phenol groups, was observed by 31P NMR spectroscopy. Thus, the most effective bifunctional LBBA (Lewis base and Brønsted acid) phosphine-Lewis base promoter system
在的氮杂森田-BaylisHillman反应Ñ -sulfonated
亚胺(Ñ -arylmethylidene -4- methylbenzenesulfonamides)与甲基
乙烯基酮(MVK),乙基
乙烯基酮(EVK),和
丙烯醛,我们发现,通过使用催化量的在具有多个
酚基的手性膦路易斯碱的基础上,可以在-20℃或室温下于THF中以> 90%ee的高收率获得相应的加合物。通过31 P NMR光谱分析研究了该过程的机理。通过31观察到通过分子内氢与
酚基团的结合而稳定的
酚盐或关键烯醇盐中间体1 H NMR光谱。因此,对于这种催化的,不对称的氮杂-Morita-BaylisHillman反应,已经确定了迄今为止报道的最有效的双功能L
BBA(路易斯碱和布朗斯台德酸)膦-路易斯碱
促进剂体系。