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.

Automated summary

This study presents the Lewis acid/base adducts of N-heterocyclic carbenes (NHCs) with selected lead(ii) and lead(iv) compounds. The reaction products include various NHC-containing plumbylenes and plumbane adducts, as well as stable diaryl substituted plumbylenes which decompose in solution.