Phosphazenes: I. Reactions with electron-deficient alkenes
摘要:
Triphenylphosphazenes reacted with methyl vinyl ketone, methyl acrylate, methyl methacrylate, and dimethyl maleate to give the corresponding substituted dihydropyrazoles.
Reactions of diazo esters with electron-deficient alkenes in the presence of Lewis acids
作者:R. A. Novikov、D. N. Platonov、V. A. Dokichev、Yu. V. Tomilov、O. M. Nefedov
DOI:10.1007/s11172-010-0194-0
日期:2010.5
Abstract1,3-Dipolar cycloaddition reaction of diazo esters to electron-deficient dipolarophiles to yield the corresponding 1- or 2-pyrazolines was found to be significantly accelerated with Lewisacids (Yb(OTf)3, Sc(OTf)3, GaCl3, EtAlCl2). The use of GaCl3 as the catalyst leads to the acceleration not only of the 1,3-dipolar cycloaddition reaction, but also subsequent insertion of the CHCO2Me electrophilic