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Synfacts 2008(1): 0018-0018  
DOI: 10.1055/s-2007-991467
Synthesis of Heterocycles
© Georg Thieme Verlag Stuttgart · New York

Dihydroisoquinolin-1-ylphosphonates via a Copper-Catalyzed Three-Component Reaction

Contributor(s): Victor Snieckus, Johnathan Board
Q. Ding, B. Wang*, J. Wu
Shanghai Institute of Organic Chemistry, Fudan University, Shanghai and Jiangxi Normal University, Nanchang, P. R. of China
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Publication History

Publication Date:
18 December 2007 (online)

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Significance

A three-component reaction of an ortho-acetylenic benzaldehyde, an amine, and diethyl phosphite affording 1,2-dihydroisoquinolin-1-ylphosphonates in generally good to excellent yield is reported. The reaction is proposed to proceed via condensation of the amine with the benz­aldehyde followed by nucleophilic attack by the phosphonate on the resulting imine. Coordination of the alkyne with copper(I) iodide then activates it toward cyclization with the secondary amine. Evidence for this mechanism is given in the form of the isolated intermediate shown. However, subjecting this intermediate to 5% CuI (undisclosed solvent and temperature) generated the expected 1,2-dihydroisoquinolin-1-ylphosphonate in only 14% yield.