Synthesis of indolizines and pyrrolo[2,1-b]azoles from 2-pyridylmagnesium bromide and 2-lithiated azoles using tris(alkylthio)-cyclopropenyl cations as a three-carbon building block

A convenient method for the preparation of indolizines 3 and 4 and pyrrolo2,1-b]azoles 7a-e from 2-pyridylmagnesium bromide and 2-lithiated azoles 6a-e , respectively, was developed by using tris(tert-butylthio)- and tris(isopropylthio)cyclopropenyl cations 1 and 2 as a three-carbon building block.