N-heterocyclic carbene and cyclic (alkyl)(amino)carbene adducts of plumbanes and plumbylenes

Lewis-acid/base adducts of N-heterocyclic carbenes (NHCs) and the cyclic (alkyl)(amino)carbene cAAC(Me) (1-(2,6-di-iso-propylphenyl)-3,3,5,5-tetramethyl-pyrrolidin-2-ylidene) with selected lead(ii) and lead(iv) compounds are presented. The reaction of the NHCs Me(2)Im(Me) (1,3,4,5-tetramethyl-imidazolin-2-ylidene), iPr(2)Im(Me) (1,3-di-isopropyl-4,5-dimethyl-imidazolin-2-ylidene), Dipp(2)Im (1,3-bis-(2,6-di-isopropylphenyl)-imidazolin-2-ylidene) and cAAC(Me) (1-(2,6-di-iso-propylphenyl)-3,3,5,5-tetramethyl-pyrrolidin-2-ylidene) with PbI2 yielded the NHC-containing plumbylenes NHC.PbI2 (NHC = Me(2)Im(Me) (1), iPr(2)Im(Me) (2), Dipp(2)Im (3) and cAAC(Me.)PbI(2) (4)). Using the Pb(iv) compound PbCl2Ph2, the plumbane adducts (NHCPbCl2Ph2)-Pb-. (NHC = Me(2)Im(Me) (5), iPr(2)Im(Me) (6), Dipp(2)Im (7)) and cAAC(Me.)PbCl(2)Ph(2) (8)) were isolated in high yields. Reduction of the lead(iv) adducts 5 and 6 with excess KC8 afforded the diaryl substituted plumbylenes Me(2)Im(Me.)PbPh(2) (9) and iPr(2)Im(Me.)PbPh(2) (10), which are stable in the solid state but decompose in solution.