Sterically constrained tricyclic phosphine: redox behaviour, reductive and oxidative cleavage of P-C bonds, generation of a dilithium phosphaindole as a promising synthon in phosphine chemistry.

ABSTRACT: The redox behaviour of sterically constrained tricyclic phosphine 3a was investigated by spectroelectrochemistry. The data suggested a highly negative reduction potential with the reversible formation of a dianionic species. Accordingly, 3a reacted with two equivalents of Li/naphthalene by reductive cleavage of a P-C bond of one of the PC₄ heterocycles. The resulting dilithium compound 5 represents a phosphaindole derivative with annulated aromatic C₆ and PC₄ rings. It is an interesting starting material for the synthesis of new heterocyclic molecules, as was shown by treatment with Me₂SiCl₂ and PhPCl₂. The structures of the products (6 and 7) formally reflect ring expansion by insertion of

SUBMITTER: Brand A 

PROVIDER: S-EPMC8179454 | biostudies-literature | 2021 Jan

REPOSITORIES: biostudies-literature