Organic Chemistry

Ligand enabled disproportionation of 1,2-diphenylhydrazine at a P(V)-center



We present herein the synthesis of a nearly square pyramidal chlorophosphorane supported by the tetradentate bis(amidophenolate) ligand, N,N’-bis(3,5-di-tert-butyl-2-phenoxy)-1,2-phenylenediamide. After chloride abstraction the resulting phosphonium cation efficiently catalyzes the disproportionation of 1,2-diphenylhydrazine to aniline and azobenzene. Mechanistic studies, spectroscopic analyses and theoretical calculations suggest that it is the combination of high electrophilicity at the cationic P(V)-center, which originates from the geometry constraints imposed by the rigid pincer ligand, and the ability of the o-amidophenolate moieties to act as electron reservoir what leverages this unprecedented reactivity mode for P(V)-centres. This study illustrates the promising role of cooperativity between redox-active ligands and phosphorus for the design of organocatalysts able to promote redox processes.


Thumbnail image of Manuscript_hydrazine disproportionation.pdf

Supplementary material

Thumbnail image of Supporting_Information.pdf
Supporting Information
Experimental part; characterization of products; X-ray structures and theoretical calculations

Supplementary weblinks

Web page of Prof. Alcarazo
Includes research areas, group members and list of publications