title: One-Pot Aminoethylation of Indoles/Pyrroles with Alkynes and Sulfonyl Azides.
abstract: A general and efficient one-pot aminoethylation of substituted indoles/pyrroles was accomplished for the synthesis of various tryptamine derivatives employing a combination of alkynes and sulfonyl azides as readily accessible aminoethylating agents. The reaction features a successful integration of copper-catalyzed alkyne and azide cycloaddition to N-sulfonyl-1,2,3-triazole, rhodium-catalyzed selective insertion of α-iminocarbenes onto the C3-H bond of indoles, and reduction of the resultant enamides to tryptamine derivatives employing either NaCNBH3 or palladium catalyst, in one-pot. The reaction also showed excellent functional-group tolerance and allowed the synthesis of various substituted tryptamines in good to excellent yield. This transformation constitutes a one-pot formal regioselective functionalization of terminal alkynes. Utility of the synthesized tryptamine was further demonstrated in the synthesis of dihydro-β-carboline and tryptoline.
authors.affiliation: Department of Chemistry, Indian Institute of Technology Madras, Chennai 600036 (India).
authors.forename: Shanmugam
authors.initials: S
authors.lastname: Rajasekar
authors.affiliation: Department of Chemistry, Indian Institute of Technology Madras, Chennai 600036 (India).
authors.forename: Dongari
authors.initials: D
authors.lastname: Yadagiri
authors.affiliation: Department of Chemistry, Indian Institute of Technology Madras, Chennai 600036 (India). anbarasansp@iitm.ac.in.
authors.forename: Pazhamalai
authors.initials: P
authors.lastname: Anbarasan
keywords: aminoethylation; indoles; rhodium; triazoles; tryptamine