Amidoalkylation of heteroaromatic compounds with adducts of acyl chlorides and 3,4-dihydroisoquinoline and isoquinoline

Abstract

Abstract:The N-acyliminium intermediates of 3,4-dihydroisoquinoline and salts of isoquinoline with acyl chlorides were successfully used as amidoalkylating reagents toward synthesis of heterocyclic aromatics as indole, pyrrole, thiophene and pyrazine.

(±)-Ethyl 6,7-dimethoxy-1-(1H-pyrrol-2-yl)-1,2,3,4-tetrahydroisoquinoline-2-carboxylate

“…For related crystal structures, see: Kolev et al (2007); Petrova et al (2007); Petrova et al (2005); Rajnikant et al (2002); Shishkina et al (2005); Venkov et al (2004); Vincente et al (2005). Symmetry code: (i) Àx; y À 1 2 ; Àz þ 1 2 .…”

“…The title compound has been obtained following the procedure described by Venkov et al, 2004. Colorless crystals of (I) suitable for X-ray diffraction were obtained by slow evaporation from ethanol/water (2:1) solution.…”

N‐Acyliminium Reagents of 3,4‐Dihydro‐β‐carboline and Acyl Chlorides in the Reaction of Intermolecular α‐Amidoalkylation Toward Heteroaromatics

“…[3] Recently, we have reported the utilization of 3,4-dihydroisoquinoline for preparation of 1-heteroaryl-2-acyl-1,2,3,4-tetrahydroisoquinolines via intermolecular a-amidoalkylation. [4] In this paper, we continue our research with another cyclic imine-3,4-dihydro-b-carboline 1. The obtained N-acyliminium reagents 3 are successfully used in a reaction of intermolecular a-amidoalkylation toward heteroaromatic compounds.…”

Alkylative coupling of enaminones and benzimidazole

“…14 We have previously used adducts of cyclic imines and acyl chlorides as electrophilic reagents in an intermolecular α-amidoalkylation reaction toward aromatics and methylene active carbonyl compounds. [15][16][17][18] Now the same strategy has been successfully applied for coupling of benzimidazole and cyclic enaminones. Scheme 1.…”