Phosphine-Catalyzed γ'-Carbon 1,6-Conjugate Addition of α-Succinimide Substituted Allenoates with Para -Quinone Methides: Synthesis of 4-Diarylmethylated 3,4-Disubstituted Maleimides.

In this paper, an interesting γ'-carbon 1,6-conjugate addition for phosphine-catalyzed α-succinimide substituted allenoates has been disclosed. A wide array of substrates was found to participate in the reaction, resulting in the production of diverse 4-diarylmethylated 3,4-disubstituted maleimides with satisfactory to outstanding yields. Furthermore, a plausible mechanism for the reaction was proposed by the investigators.