Regioselective functionalization of heterocyclic rings: synthesis and reactions of 1-methyl-2-(trimethylsiloxy) pyrrole and 2-(trimethylsiloxy) thiophene
2a, X= NMe b, X= S 1 detected in the reaction mixture at-78" C but rapidly decomposed at room temperature, probably owing to the presence of diethylamine produced during the reaction. Addition of 2 equiv of trimethylchlorosilane (Me3SiC1) and 1.2 equiv of Me3SiDEA to 2b gave lb in 65% yield, after distillation, as a colorless oil that could be kept indefinitely under an inert atmosphere.
