Insertion of the N,B,N-chelated germylene into P-Cl Bond(s) in selected chlorophosphines

Abstract

The reaction of the N,B,N-chelated germylene [(i-Pr)2NB(NDmp)2]Ge (1) (where Dmp = 2,6-Me2C6H3) with Ph2PCl in 1:1 stoichiometric ratio led to a smooth insertion into the P-Cl bond under formation of [(i-Pr)2NB(NDmp)2]Ge(PPh2)Cl (2). Similarly, the treatment of 1 with RPCl2 in 2:1 stoichiometric ratio resulted in double insertion products {[(i-Pr)2NB(NDmp)2]GeCl}2(PR) [where R = Ph (3) or t-Bu (4)]. The products were characterized by 1H, 13C{1H} and 31P{1H} NMR spectroscopy and in the case of 2 and 4 by single-crystal X-ray diffraction analysis. During an initial attempt to crystallize 4, single-crystals of its decomposition product {[(i-Pr)2NB(NDmp)2]GeCl}{[(i-Pr)2NB(NDmp)(NHDmp)]GeCl2}(Pt-Bu) (5) were fortuitously isolated and its structure was determined by X-ray diffraction analysis and in solution by NMR studies. The attempt to synthesize compound 5 in a controlled manner by the reaction of 4 with one equiv. of HCl led to the mixture of 5 and {[(i-Pr)2NB(NDmp)(NHDmp)]GeCl2}2(Pt-Bu) (6) that could be separated by a fractional crystallization.