Complexes of P-stabilised carbanions with s- and p-elements

The chemistry of complexes of the main group metals (Groups 1, 1 13. 14. and 15, including Si and As) with P-stabilised carbanions is described. Such ligands. in which a carbanion Centre is immediately adjacent to a P(111) or P(V) Centre are remarkably versatile and adopt a wide range of coordination modes. depending on the nature of the metal Centre. the presence of co-ligands and the ligand substituents: certain main group derivatives have also found applications in organic synthesis, especially for the olefination of carbonyl compounds (Horner, or Homer-Wadsworth-Emmons reagents). The focus of the review is on complexes which have been structurally characterised, either by crystallographic means or by unambiguous spectroscopic evidence. (C) 2002 Elsevier Science B.V. All rights reserved.