Sterically protected organophosphorus compounds of unusual structures

GRAPHICAL ABSTRACT

ABSTRACT

The character of bis(2,4,6-tri-t-butylphenyl)diphosphene is described experimentally and theoretically. The diphosphene is sterically protected and the structure can be characterized by spectroscopic as well as crystallographic analyses. Theoretical calculation on the diphosphene strongly suggests that the P˭P bond is an isolated double bond and that the P-C bonds are single covalent bond. The reactivity has been investigated including photolysis, oxidation, sulfurization, transition-metal complex formation, carbene addition, and so on. Plausible mechanism for the reaction of diphosphene with 3,4,5,6-tetrachlorocyclohexa-3,5-diene-1,2-dione to a pentavalent spiro product is discussed based on the product analysis.

KEYWORDS:

• Steric protection
• diphosphene
• low coordination
• unusual structure

Acknowledgment

Thanks to Prof. Shigekazu Ito at Tokyo Institute of Technology for theoretical calculations of Mes^*P=PMes^*.