Carbonyl sulfide insertion reactions

Carbon disulfide also reacts with tin amides, such as Me3SnNMc2, to give the insertion products . Tin alkoxides react similarly to give the 1 1 adducts. For example, reaction of bistributyltin oxide 103 with carbon disulfide affords bis(tributyltin)sulflde 105 with elimination of carbonyl sulfide . The reaction involves the insertion product 104 as an intermediate. 

A third kind of reactivity is related to the silyl substitution mechanism in that it involves an intermediate N-Si bond cleavage. Insertion of heterocumulenes such as CO2 is common for N-M bonds [7], including the -NSiR3 function in 1 or other molecules [8, 9]. We now report the result of the reaction between 1 and the unsymmetrical carbonyl sulfide, 0=C=S. 

CO2 analogues such as allenes, ketenes, isocyanates, carbodiimides, and carbonyl sulfide also insert. Studies of insertion reactions of Cp2ZrR2 (R = Me, CH2Ph, Ph) show that the ease of insertion follows the series Me > Py CH2Ph and Ph2C=C=0>PhN=C=0>p-MeC6H4N=C=NC6H4Me-p>C02. The data have been reasonably interpreted as evidence for precoordination before insertion occurs. A four-center transition state similar to that depicted above for the thorium system is favored. 

Eventually we formed carbonyls in the liquid phase by redox disproportionation of nickel and cobalt derivatives of organic thioacids. In the reaction between nickel(II) dithiobenzoate and carbon monoxide in the presence of HS ion we assumed the formation of a sulfur-bridged nickel(IV) complex (VII, 32). More recent investigations (84), however, have shown that half the nickel appears as a monomeric nickel(II) complex of the same empirical formulation, formed by insertion of a sulfur atom in the dithio ligand, the other half of the nickel being reduced to nickel(O) by the sulfide. 

The catalytic potential of transition metal sulfides for abiotic carbon fixation was assayed. It was found that at 2000 bar and 250 °C, the sulfides of iron, cobalt, nickel, and zinc promote the hydrocarboxylation reaction via carbonyl insertion at a metal sulfide bound alkyl group. The results of the study support the hypothesis that transition metal sulfides may have provided useful catalytic functionality for geochemical carbon fixation in a prebiotic world [141]. 

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