N-Heterocyclic Carbene Analogues with Low-Valent Group 13 and Group 14 Elements: Syntheses, Structures, and Reactivities of a New Generation of Multitalented Ligands

Reactivity of Diaminogermylenes with Ruthenium Carbonyl: Ru3Ge3 and RuGe2 Derivatives

“…Quite a few stable N-heterocyclic group-14 metal ylidenes (NHMs, where M can be Si, Ge, Sn, or Pb) were prepared and characterized 1,2 before the isolation of the first stable N-heterocyclic carbene (NHC), which was reported in 1991. 3 However, in contrast with the coordination chemistry of NHMs, which has been developed gradually but slowly since their discovery, 4,5 that of NHCs blossomed very rapidly 6 because some NHC complexes soon demonstrated to be excellent homogeneous catalysts for processes that are very useful in organic synthesis.…”

Synthesis and Characterization of N-Heterocyclic Carbene-Coordinated Silicon Compounds Bearing a Fused-Ring Bulky Eind Group

“…Over many years, a number of unsaturated silicon compounds have been successfully obtained by virtue of the complexation of metal ions and/or coordination of ligands (mainly Lewis bases) in addition to steric protection with bulky substituents [1][2][3][4][5][6][7][8][9][10][11]. Among them, the coordination chemistry of highly-reactive halosilylenes, i.e., halogen-substituted divalent Si(II) species, have attracted a lot of attention as potentially useful precursors for the construction of a wide range of silicon-containing compounds [12][13][14][15][16][17].…”

One-Pot Synthesis of Heavier Group 14 N-Heterocyclic Carbene Using Organosilicon Reductant

“…Subsequently, the isolation of heavier Group 14 analogues of 'Arduengo type' carbene NHE (E = Si, Ge, and Sn) have been the subject of intense study, both for fundamental interests and potential applications in transition metal catalysis, similar to the NHCs. To date, a handful of NHEs have been synthesized and structurally characterized [3,4]. Obviously, the heavier analogues possess distinct electronic features compared to the NHCs, and hence exhibit different reactivities [3,4].…”

“…To date, a handful of NHEs have been synthesized and structurally characterized [3,4]. Obviously, the heavier analogues possess distinct electronic features compared to the NHCs, and hence exhibit different reactivities [3,4]. While N-heterocyclic silylenes (NHSi) have been engaged as ancillary ligands in numerous homogeneous catalysis [5][6][7], N-heterocyclic germylenes (NHGe) serve as a precursor for polymerization chemistry [8][9][10] and also for chemical vapour depositions [11].…”

“…Typically, the synthesis of the five-membered N-heterocyclic tetrylenes involves the reaction between N-substituted 1,4-diaza-1,3-butadiene, Group 14 halides, and the harsh alkali metal based reducing agents (Scheme 1) [3,4]. In the case of NHGe and NHSn, the initial step involves the reduction of N-substituted 1,4-diaza-1,3-butadiene by lithium metal, followed by cyclization of the dianion with the corresponding Group 14 E(II) halides [12][13][14][15].…”