Exploration of the Carbenoid and Vinylogous Reactivity of Diazo Arylidene Succinimides (DAS) with Benzyl Thioethers under Rhodium Catalysis

Abstract

Herein, we have explored the reactivity of diazo arylidene succinimide (DAS) through rhodium catalysis to achieve [1,2]/ [1,4]-Stevens rearrangement of benzyl thioether. The protocol has successfully demonstrated substituent-dependent competitive reactivity of DAS to tune the ratio of [1,2]- Stevens and [1,4]- Stevens rearrangement products. This protocol developed a new C-C and C-S bond between carbenoid/vinylogous benzyl thioether. This catalytic protocol works smoothly in an environmentally benign solvent to afford the corresponding desired products with moderate to good yields. The protocol developed is useful for the construction of biologically important maleimide-S linkage, featured in many pharmaceutical scaffolds, which are useful for bioconjugation in medicines. The protocol also proved to be scalable on a gram-scale quantity.