화학공학소재연구정보센터
Inorganic Chemistry, Vol.55, No.12, 6186-6194, 2016
New Selective Synthesis of Dithiaboroles as a Viable Pathway to Functionalized Benzenedithiolenes and Their Complexes
A synthetic protocol to synthesize 2-bromobenzo-1,3,2-dithiaboroles in one step from easily accessible benzene bis(isopropyl thioether)s has been developed. The reaction is remarkably specific in converting substrates with two adjacent (PrS)-Pr-i moieties while leaving isolated thioether functions and other functional groups intact. On the basis of the spectroscopic detection or isolation of reaction intermediates, a mechanistic explanation involving a neighbor group-assisted dealkylation as a key step is proposed. The resulting products featuring one or two dithiaborole units were isolated in good yields and fully characterized. Subsequent methanolysis, which was carried out either as a separate reaction step or in the manner of a one-pot reaction, gave rise to functionally substituted benzenedithiols. The feasibility of a methylphosphoryl-substituted benzenedithiol to act as a dianionic S,S-chelating ligand was demonstrated with the formation of paramagnetic Ni(III) and Co(III) complexes. Selective reduction of the phosphoryl group afforded a rare example of a phosphino dithiol which was shown to act as a monoanionic P,S-bidentate ligand toward Pd(II). All complexes were characterized by spectral data and X-ray diffraction studies, and the paramagnetic ones also by superconducting quantum interference device magnetometry.