Phosphine-mediated [2+2] cycloaddition of internal alk-2-ynoate and alk-2-ynone to [60]fullerene

Abstract

Treatment of RCH2C≡CCOX with [60]fullerene in the presence of tricyclohexylphosphine (PCy3) afforded a [2+2] cycloaddition product (1:R=H, X=OMe); 2:R=Bu, X=OMe; 3:R=X=Me which resulted from addition of the β,γ-carbons of RCH2C≡CCOX to the carbon-carbon double bond across a 6/6 ring junction of [60]fullerene.