Nucleophilic Addition of Sulfonamides to Bromoacetylenes: Facile Preparation of Pyrroles
摘要:
Nucleophilic addition of sulfonamides to 1-bromo-1-alkynes provided (2)-N-(1-bromo-1-alken-2-yl)-p-toluenesulfonamides in good yield and in a highly regio- and stereoselective manner. Treatment of product (2)-N-(1-bromo-1-octen-2-yl)-N-allyl-p-toluenesulfonamide with a palladium catalyst under Heck conditions afforded 1-(p-toluenesulfonyl)-2-hexyl-4-methylpyrrole in good yield. Other pyrroles with various substituents can also be prepared in good yield by this method.
Nucleophilic addition of imidazolines to 1-halo-1-aikres takes place by simple heating in DMF without any additives to give (Z)-N-(1-hato-1-alken-2-yl)imidazolines in good yield and in a highly regio- and stereoselective manner. These reaction conditions are also valid for the similar addition of imidazoles.