Lewis Base Stabilized Group 14 Metalylenes

Abstract

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.

Tuning the π‐Accepting Properties of Mesoionic Carbenes: A Combined Computational and Experimental Study

“…The Sn center displays the expected trigonal pyramidal geometry (Cl−Sn−C=87.64(15)°, Cl−Sn−N=97.20(15)°). The Sn−C bond length of 2.295(7) Å is close to what was reported for a SnCl 2 complex with a MIC ligand featuring phenyl groups in C2 and C4 positions (Sn−C=2.308(9) Å) [71] …”

“…The Sn−C bond length of 2.295(7) Å is close to what was reported for a SnCl 2 complex with a MIC ligand featuring phenyl groups in C2 and C4 positions (Sn−C=2.308(9) Å). [71] …”

Reactions of Si2Br6 with N‐Heterocyclic Carbenes

“…These so‐called “abnormal carbenes” ( a NHCs), which bear the carbene center in 4‐ or 5‐position, have long been fleeting curiosities in main‐group chemistry until Bertrand and co‐workers isolated the first crystalline a NHC in 2009 . a NHCs are stronger σ‐donors than normal NHCs; reactions with silanes lead to formation of 4‐silyl‐functionalized imidazolium salts . To date, a variety of 4‐silyl‐substituted NHCs and their corresponding imidazolium salts have been reported (Figure ),[26b], most of which result from reactions of an NHC with the corresponding silane upon addition of a strong base.…”

Coordination chemistry of ditopic carbanionic N-heterocyclic carbenes

“…Furthermore, 18 can be used as a strong Lewis base in the stabilization of heavy group 14 metallylenes [50,51]. Addition of IPr·SiCl 2 , GeCl 2 ·dioxane or SnCl 2 to the abnormal carbene afforded the aNHC adduct of the group 14 element dichloride (20) (Fig.…”