Lewis Base Stabilized Group 14 Metalylenes

The chemistry of stable metalylenes (the heavier group 14 element analogues of carbenes) is an intriguing target of main group chemistry due to their synthetic potential and industrial application. In the present study, we report on the utilization of an abnormal N-heterocyclic carbene (aNHC) and a cyclic alkyl-amino carbene (cAAC) as a Lewis base for the syntheses of compounds aNHC·SiCl2 (3), aNHC·SnCl2 (4), and cAAC·SnCl2 (5). The synthesis of silylene 3 involved the ligand-substitution reaction between NHC·SiCl2 and an aNHC. However, compounds 4 and 5 were synthesized by the reactions of aNHC and cAAC with SnCl2 in the molar ratio of 1:1. Compounds 3–5 are well-characterized with various spectroscopic methods and single-crystal X-ray structural analysis.