Application of Terminal Electrophilic Phosphinidene Complexes

Introduction

Phosphinidenes are phosphorus analogues of carbenes in which phosphorus is monovalent with an incomplete octet of electrons. Phosphinidene complexes readily react with alkenes, whereas free phosphinidenes do not react with alkenes. This indicates that the coordination of these unstable phosphorus compounds [¹] with metallic species enhances their stability as well as reactivity by increasing the electrophilicity of the phosphorus atom. A number of precursors like phosphiranes, [²] phospholenes, [²] norbornadienes, [³] 2H-azaphosphirene [4] and phosphirene [5] metal complexes are known to generate terminal phosphinidene complexes in situ via their thermal or photochemical decomposition. These phosphinidene complexes are short-lived intermediates and their existence is proved by trapping them with substituted alkenes, [6] acetylenes, [7] and organic nitriles [8] via cycloaddition reactions resulting in the formation of a variety of P-heterocycles. Recently, insertion of phosphinidene complexes into carbon-halogen bonds has been established, [9-¹¹] which affords a number of novel organophosphorus compounds.

References

• 1 Marinetti A. Mathey F. Fischer J. Mitschler A. J. Am. Chem. Soc.  1982,  104:  4484 
• 2 Mercier F. Deschamps B. Mathey F. J. Am. Chem. Soc.  1989,  111:  9098; and references therein 
• 3 Marinetti A. Mathey F. Fischer J. Mitschler A. J. Chem. Soc., Chem. Commun.  1982,  667 
• 4 Streubel R. Jeske J. Jones PG. Herbst-Irmer R. Angew. Chem., Int. Ed. Engl.  1994,  33:  80 
• 5 Borst MLG. Bulo RE. Winkel CW. Gibney DJ. Ehlers AW. Schakel M. Lutz M. Spek AL. Lammertsma K. J. Am. Chem. Soc.  2005,  127:  5800 
• 6 Streubel R. Wilkens H. Ostrowski A. Neumann C. Ruthe F. Jones PG. Angew. Chem., Int. Ed. Engl.  1997,  36:  1492 
• 7 Wilkens H. Ruthe F. Jones PG. Streubel R. Chem. Commun.  1998,  1529 
• 8 Khan AA. Neumann C. Wismach C. Jones PG. Streubel R. J. Organomet. Chem.  2003,  682:  212 
• 9 Khan AA. Wismach C. Jones PG. Streubel R. Dalton Trans.  2003,  2483 
• 10 Khan AA. Jones PG. Streubel R. Chem. Commun.  2003,  2892 
• 11 Özbolat A. Khan AA. von Frantzius G. Nieger M. Streubel R. Angew. Chem. Int. Ed.  2007,  46:  2104 
• 12 Ehlers AW. Lammertsma K. Baerends EJ. Organometallics  1998,  17:  2738 
• 13 Ehlers AW. Baerends EJ. Lammertsma K. J. Am. Chem. Soc.  2002,  124:  2831 
• 14 Mathey F. Dalton Trans.  2007,  1861 
• 15 Ionescu E. von Frantzius G. Jones PG. Streubel R. Organometallics  2005,  24:  2237 
• 16 Bulo RE. Ehlers AW. de Kanter FJJ. Schakel M. Lutz M. Spek AL. Lammertsma K. Wang B. Chem. Eur. J.  2004,  10:  2732