The Horner–Wadsworth–Emmons reaction of mixed phosphonoacetates and aromatic aldehydes: geometrical selectivity and computational investigation
作者:Jiro Motoyoshiya、Tatsuya Kusaura、Keisuke Kokin、Sei-ichi Yokoya、Yutaka Takaguchi、Susumu Narita、Hiromu Aoyama
DOI:10.1016/s0040-4020(01)00007-2
日期:2001.2
The substituent effect on the geometrical selectivity in the Horner–Wadsworth–Emmons (HWE) reaction was studied employing several mixed phosphonoacetates. Their reactions with aromatic aldehydes showed a gradual change in Z-selectivity according to the electron-withdrawing ability of the phosphonate substituents, and there was a good correlation between the observed selectivities and 31P chemical shifts
使用几种混合的膦酰基乙酸酯研究了霍纳-沃兹沃思-埃蒙斯(HWE)反应中取代基对几何选择性的影响。他们与芳族醛的反应表明,Z-选择性根据膦酸酯取代基的吸电子能力逐渐变化,并且所观察到的选择性与膦酰基乙酸酯的31 P化学位移之间具有良好的相关性。一些变量,例如金属阳离子和冠醚也影响了选择性。使用从头算和半经验计算的计算研究表明,吸电子取代基可稳定中间体以及过渡态,从而降低了增加Z的可逆性-产品。这与实验观察到的选择性一致。