Selective and Efficient Formylation of Indoles (C3) and Pyrroles (C2) Using 2,4,6‐Trichloro‐1,3,5‐Triazine/Dimethylformamide (TCT/DMF) Mixed Reagent

Abstract

This study introduces an efficient method for the selective formylation of indoles and pyrroles at the positions of C(3) and C(2), respectively. The mixture of three equivalents of N,N‐dimethylformamide and one equivalent of 2,4,6‐trichloro‐1,3,5‐triazine (cyanuric chloride) generates an easy handling formylating agent for the efficient formylation of these classes of compounds to give the corresponding aldehydes under mild reaction conditions. This procedure was highly efficient, and a range of formylated indoles and pyrroles were obtained in good to excellent yields.

Reaction Medium as the Installing Reservoir for Key Functionalities in the Molecules

“…Iranpoor et al . (2017) has carried out the formylation of indoles and pyrroles at C‐3 and C‐2 positions, respectively, 2,4,6‐trichloro‐1,3,5‐triazine (cyanuric chloride, TCT) by activating DMF as a source of formyl moiety (Scheme ) . TCT along with DMF at room temperature is capable of generating the formyl moiety by four different possibilities ( 105 – 108 , Scheme ).…”