Conceptual advances in nucleophilic organophosphine-promoted transformations.

Catalysis by trivalent nucleophilic organophosphines has emerged as an essential tool in organic synthesis. Several new organic transformations promoted by phosphines substantiate and complement the existing synthetic chemistry tools. Mere design of the substrate and reagent combinations has introduced new modes of reactivity patterns, which are otherwise difficult to achieve.

Beyond the Corey-Chaykovsky Reaction: Synthesis of Unusual Cyclopropanoids via Desymmetrization and Thereof.

Desymmetrization-based protocols for the synthesis of highly functionalized indeno-spirocyclopropanes and cyclopropa-fused indanes have been established through unexpected reactions triggered by the Corey-Chaykovsky reagent. These structures were further elaborated in one step to privileged scaffolds such as fluorenones, indenones, and naphthaphenones. For instance, an acid-catalyzed transformation of indeno-spirocyclopropanes provided fluorenones via a homo-Nazarov-type cyclization, and naphthaphenones were obtained via an acid-catalyzed cyclopropane ring-opening/retro-Michael sequence.