Application of N-heterocyclic silylenes in low-valent group 13, 14 and 15 chemistry

N-Heterocyclic silylenes (NHSis) are the silicon analogues of N-heterocyclic carbenes (NHCs), which feature a neutral divalent silicon atom directly bonded to at least one nitrogen atom in a heterocyclic framework. NHSis have long been utilized as versatile ligands in transition metal chemistry due to their strong σ-donating character. In recent years, significant progress has been achieved in the application of NHSis for the stabilization of low-valent main group element compounds, which allowed the synthesis and comprehensive reactivity study of these fascinating species. This review summarizes the recent achievements in this new and flourishing field, including synthetic approaches, structural features and reactivity of these NHSi-stabilized low-valent main group element compounds.