Stereochemical features of low-coordinate organophosphorus compounds

Abstract

Various kinds of sterically protected low-coordinate phosphorus compounds with Mes* (2,4,6-tri-tert-butylphenyl) group such as diphosphenes, 1-phosphaethenes, 1-phosphaallenes, 1,3-diphosphaallenes, and 3,4-diphosphinidenecyclobutenes are discussed in terms of stereochemistry including E/Z photo-isomerization around the P = P or P = C bond and R/S identification of rotational isomers around the crowded P–C bonds. (π-Allyl)palladium complexes ligated with 3,4-diphosphinidenecyclobutenes are useful in catalytic organic reactions such as the Tsuji-Trost reaction and the mechanism is proposed to interpret products.

Graphical Abstract

Keywords:

• Steric protection
• diphosphene
• phosphaalkene
• low coordination
• photo-isomerization
• hindered rotation

Acknowledgements

The author thanks Prof. A. J. Arduengo, III at the University of Alabama, Prof. Shigekazu Ito at Tokyo Institute of Technology, Prof. Kozo Toyota and Dr. Shigeru Sasaki at Tohoku University, Prof. Fumiyuki Ozawa at Kyoto University, Prof. Shigeru Nagase at Institute of Molecular Science (Okazaki), and Prof. Yoshio Okamoto at Nagoya University for supporting the research mentioned in this article.