A flexible, highly efficient method for the preparation of homochiral oxazaphospholidine-boranes
摘要:
An efficient and operationally simple procedure for the synthesis of 2-substituted 3,4-dimethyl-5-phenyloxazaphospholidine derivatives has been developed. This new method permits the large scale preparation of a range of electronically and sterically differentiated homochiral monophosphine precursors.
Aminophosphines RP(NR′2)2 (R Ph, cyclo-Hex, (−)-Men, t-Bu; R′ Me, Et) as ligands L in complexes (CO)5ML (M Cr, Mo, W) have been found to react with HX (X Cl, Br) mainly under substitution of only one of the two dialkylamino groups by halogen. Under similar conditions the free phosphines are converted into the dihalogenphosphines. The halogenamino complexes (CO)5MPRXNR′2 are readily accessible