94633-32-6Relevant articles and documents
Pyrrole Studies. Part 28. The Effect of Steric Hindrance upon the Reaction of 2-Vinylpyrroles with Dimethyl Acetylenedicarboxylate
Jones, R. Alan,Saliente, Teresa Aznar,Arques, Jose Sepulveda
, p. 2541 - 2543 (2007/10/02)
Steric interaction between the N-substituent and the vinyl substituent of 1-substituted 1-(1-substituted pyrrol-2-yl)ethenes destabilises the cisoid conformation (1b), thereby inhibiting (?4+?2) cycloaddition reactions leading to dihydroindoles.Bulky N-substituents also sterically inhibit the Michael addition of dimethyl acetylenedicarboxylate at the 5-position of the pyrrole ring.