CO2 Derivatives of Molecular Tin Compounds. Part 2: Carbamato, Formato, Phosphinoformato and Metallocarboxylato Complexes

Abstract

Single-crystal X-ray diffraction structures of organotin compounds bearing hemicarbonate and carbonate ligands were recently reviewed by us—“CO2 Derivatives of Molecular Tin Compounds. Part 1: Hemicarbonato and Carbonato Complexes”, Inorganics2020, 8, 31—based on crystallographic data available from the Cambridge Structural Database. Interestingly, this first collection revealed that most of the compounds listed were isolated in the context of studies devoted to the reactivity of tin precursors towards carbon dioxide, at atmospheric pressure or under pressure, thus highlighting the suitable disposition of Sn to fix CO2. In the frame of a second part, the present review carries on to explore CO2 derivatives of molecular tin compounds by describing successively the complexes with carbamato, formato, and phosphinoformato ligands, and obtained from insertion reactions of carbon dioxide into Sn–X bonds (X = N, H, P, respectively). The last chapter is devoted to X-ray structures of transition metal/tin CO2 complexes exhibiting metallocarboxylato ligands. As in Part 1, for each tin compound reported and when described in the original study, the structural descriptions are supplemented by synthetic conditions and spectroscopic data.

Tin-catalyzed reductive coupling of amines with CO2 and H2

“…In the second step, CO 2 is reduced by the tin hydride to tin formate (Scheme 3, step II); facile CO 2 insertion into tin hydride bonds has been repeatedly demonstrated, 59,60 and is even reversible for some tin hydrides, such as tri-n-butyltin hydride. 61 Attempted CO 2 reduction to tin formate by FLP4 without morpholine resulted only in the reduction of 2,4,6collidine (indicated by the absence of the aromatic peak and the presence of two new methyl group signals in 1 H NMR, see ESI †).…”

Glycerol as Ligand in Metal Complexes—A Structural Review

“…Synthetically, glycerol carbonate is readily available via transesterification reactions by reacting glycerol with linear dialky carbonates, alkylene carbonate and urea [46]. In the late 2000s and based on previous investigations on the direct carbonation of alcohols [47,48], the research groups of Ballivet-Tkatchenko and Behr investigated the synthesis of glycerol carbonate from CO 2 and glycerol using diorganotin(IV) complexes as precatalysts-organotin derivatives are known to be highly reactive towards carbon dioxide, and structural data reflecting this behaviour had recently been reviewed [49,50]. As part of this work, they demonstrated the possible coordination of glycerol to tin centres by isolating the di-tert-Bu 2 Sn(1,2-glycerolate) complex ( 20) [25].…”