Selective cyclotrimerization of enones and alkynes by a nickel and aluminum catalytic system

N Mori, S Ikeda, Y Sato

Index: Mori, Naoyoshi; Ikeda, Shin-Ichi; Sato, Yoshiro Journal of the American Chemical Society, 1999 , vol. 121, # 12 p. 2722 - 2727

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Citation Number: 70

Abstract

Enones 1 reacted with two molecules of alkynes 2 (R= R'in eq 1) in the presence of a nickel (0) and aluminum catalytic system to give cyclotrimerization adducts regioselectively. Aluminum phenoxide (Me n Al (OPh) 3-n (n= 0-3)) functions as a Lewis acid cocatalyst and activates 1. Stoichiometric experiments suggest that the cycloaddition of 1 and 2 proceeds via nickelacyclopentadiene intermediates, which are formed by the oxidative coupling of ...