An easy and direct synthetic route to phosphamido niobocenes through nucleophilic attack of phosphide niobocene complexes on acyl halides

摘要

The synthesis of the new cationic functionalized phosphane niobocene complexes [Nb(-η5-C5H4SiMe3)2(P(CH2CO(C6H5))Ph2)(L)]Cl, L=CO (3) or CNXylyl (4), and new phosphamido-niobocene complexes [Nb(η~5-C5H4SiMe3)2(P{CO(C6H5)}Ph2)(L)]Cl, L=CO (5), CNXylyl (6), [Nb(η~5-C5H4SiMe3)2(P(COCH(C6H5)2)Ph2}(L)]Cl, b=CO (7) or CNXylyl (8), has been achieved. The complexes were prepared by reaction of the Lewis base niobocene complexes [Nb(η~5-C5H4SiMe3)2(PPh2)(L)], L=CO (1) or CNXylyl (2), with the appropriate RX (PhCOCH2Cl, chloroacetophenone) and RCOX (PhCOCl, benzoyl chloride, Ph2CHCOCl, diphenylacetyl chloride) reagents through the formation of new P-C bonds in the corresponding nucleophilic substitution reactions. These processes afforded new metallophosphanes in which one of the substituents on the phosphorus atom contains a ketonic moiety. The presence of the carbonyl group in the coordination sphere of phosphorus increases the coordination possibilities of the phosphane and enriches the applications of these complexes.