Organic letters

Phosphine-initiated general base catalysis: Facile access to benzannulated 1, 3-diheteroatom five-membered rings via double-Michael reactions of allenes

J Szeto, V Sriramurthy, O Kwon

Index: Szeto, Judy; Sriramurthy, Vardhineedi; Kwon, Ohyun Organic Letters, 2011 , vol. 13, # 20 p. 5420 - 5423

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Citation Number: 38

Abstract

General base-catalyzed double-Michael reactions of allenes with various dinucleophiles are described. The reactions are facilitated most efficiently by a catalytic amount of trimethylphosphine, affording six types of C2-functionalized benzannulated five-membered heterocycles: benzimidazolines, benzoxazolines, benzothiazolines, 1, 3-benzodioxoles, 1, 3- benzoxathioles, and 1, 3-benzodithioles. This atom-economical reaction is operationally ...