Leaving Group and Regioselectivity Switches in the Aminoalkylation Reaction of Indoles and Related Heterocycles with α‐Amido Sulfones

Abstract

AbstractThe regioselective aminoalkylation of indoles and related heterocycles with α‐amido sulfones under basic conditions has been studied. The reaction that employed the MeMgBr/MgBr2 system provided high yields of 3‐(1‐carbamoylalkyl)indoles. On the other hand, the reaction that used Cs2CO3 afforded 1‐(1‐carbamoylalkyl)indoles exclusively in high yields. The first reaction constitutes a switch of the leaving group of the α‐amido sulfone in comparison to previously reported reactions between indoles and α‐amido sulfones, which provided 3‐(1‐arylsulfonylalkyl)indoles. The second reaction constitutes a switch in the regioselectivity. The extensions of these C‐ and N‐aminoalkylations starting from pyrroles and 7‐azaindole have also been studied. Structurally diverse aminoalkylated indoles, pyrroles, and 7‐azaindoles were obtained with excellent yield in most of the cases.