SYNTHESIS OF IMINOPHOSPHORANES AS LIGANDS FOR ORGANOMETALLIC COMPOUNDS

Iminophosphoranes are organic compounds of general composition R₃P=NR and can be considered as nitrogen analogues to phophorus ylides. They can be obtained by the Staudinger[1] and Kirsanov[2] reactions. This compounds have multiple applications: they can be used as intermediates in reactions such as the Aza-Wittig[3], as a protecting group for amines or as a ligands for coordinated or cyclometallated compounds[4].

The P=N bond is highly polarized, so that the nitrogen bears a partial negative charge. This feature makes them act as σ-donors with only minor π-acceptor properties, so when forming coordination compounds they can be displaced by other ligands[5].

Acknowledgments

We wish to thank the financial support received from the Xunta de Galicia (Galicia, Spain) under the Grupos de Referencia Competitiva Programme Projects GRC2015/009.

[1] H Staudinger, J Meyer, Helv. Chim. Acta 2 (1): 635  

[2] A.V. Kirsanov, Izv. Akad. Nauk. SSSR, Ser. Khim. (1950) 426-437

[3] F. Palacios, C. Alonso, D. Aparicio, G. Rubiales, J.M. de los Santos, Tetrahedron 63 (2006) 523-575;

[4] Pingrong Wei, Katie T. K. Chan and Douglas W. Stephan Dalton Trans. 2003, 3804–3810

[5] M. Fukui, K. Itoh, Y. Ishii, Bull. Chem. Soc. Jpn. 48 (1975) 2044- 2046