Synthesis 2011(20): 3371-3374  
DOI: 10.1055/s-0030-1260219
PAPER
© Georg Thieme Verlag Stuttgart ˙ New York

Synthesis of Isoquinolinium-2-yl Amides via Silver(I)-Catalyzed Ring Closure of N′-(2-Alkynylbenzylidene)hydrazides

Vsevolod A. Peshkov, Olga P. Pereshivko, Sofie Van Hove, Denis S. Ermolat’ev*, Erik V. Van der Eycken*
Laboratory for Organic & Microwave-Assisted Chemistry (LOMAC), Department of Chemistry, Katholieke Universiteit Leuven, Celestijnenlaan 200F, 3001 Leuven, Belgium
Fax: +32(16)327990; e-Mail: [email protected]; e-Mail: [email protected];
Further Information

Publication History

Received 26 June 2011
Publication Date:
08 September 2011 (online)

Abstract

An efficient one-pot protocol for the synthesis of isoquinolinium-2-yl amides starting from readily available hydrazides and 2-alkynylbenzaldehydes is described. The key step of the protocol is a silver(I)-catalyzed ring-closure of N′-(2-alkynylbenzylidene)hydrazides that are generated in situ. Isoquinolinium-2-yl amides derived from tert-butoxycarbonyl hydrazide could be further deprotected, delivering 2-aminoisoquinolinium trifluoroacetates.

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10

So far, only the application of tosyl hydrazide (12e) was sufficiently explored in related processes; see refs. 6 and 8.