ChemInform Abstract: The Topotactic Reduction of Sr₃Fe₂O₅Cl₂—Square Planar Fe(II) in an Extended Oxyhalide.

Abstract

Two unsymmetrical 1,2,4‐trithiolanes (1d and 1e) were reacted with [Pt0(PPh3)2(η2‐nbe)] (6; nbe=norborn‐2‐ene) and [Pt0(dppn)(η2‐nbe)] (11; dppn=1,8‐bis(diphenylphosphanyl)naphthalene)), respectively. Their treatment with compound 6 resulted in the formation of six‐membered platinacycles of type 7, which selectively underwent fragmentation into dithiolato complexes and thiobenzophenone (4b). The isolation of the first stable C‐substituted member of this class of compounds (i.e., compound 7e) permitted kinetic studies of this process by using UV/Vis spectroscopy. These results, together with DFT calculations, allowed us to propose a mechanism for the reactions of compound 6 with 1,2,4‐trithiolanes. In contrast, similar treatment of compound 11 with compounds 1d and 1e at room temperature did not result in any reaction. Heating the appropriate samples to 110 °C led to the formation of dithiolato complexes and η2‐thioketone compounds, thus pointing to a thermally induced [3+2]‐cycloreversion of the heterocycles as an initial step of the reaction.