Syntheses,structural characterization,and thermal behaviour of metal complexes with 3-aminopyridine as co-ligands

Transition Metal Chemistry - Six mixed metal complexes with 3-aminopyridine (3-ampy) as a co-ligand have been synthesized: catena-{[M(μ2-3-ampy)(H2O)4]SO4·H2O} (M=Ni (1) and Co (2)),...     

Organo–Phosphorus–Sulfur Heterocycles by Reactions of Phenylphosphine with Ketones

Abstract

The reaction of phenylphosphine (PhPH₂) with ketones showed conversion into a 5-membered heterocyclic ring of the type P₂SOC if 2–2.5 equivalents of sulfur (S₈) were used. X-Ray data and ³¹P, ¹³C, ¹H NMR spectra proved the formation of the (Z) diastereomer of 1,3,2,4-oxathiadiphospholane 1 ((PhPS)₂SOCMe₂) if acetone is used. Mechanistic studies displayed that small changes in the reaction pathway lead toward the formation and characterization of intermediates including 1,3,2,4,5-dithiatriphospholane, 2,4,5-triphenyl-2-sulfide (PhP)₃S₃ and 1,3,2,4-oxathiadiphospholane, and 5,5-dimethyl-2,4-diphenyl-2-sulfide ((PhPS)(PhP)SOCMe₂), which undergo reactions with acetone, subsequently yielding the abovementioned heterocyclic ring.     

Synthesis and Properties of Backbone Silylated Imidazol-2-thiones

Imidazole-2-thiones have attracted considerable interest in the past as materials for potential applications in the pharmaceutical and chemical industries. Herein, the synthesis of a series of backbone silylated 1,3-dialkylimidazol-2-thiones is reported. The developed synthesis protocol involves the silylation of N,N-dimethylimidazol-2-thione 1 followed by the addition of organochlorosilanes R_nSiCl_4–n (R=Me, Ph; n=0–4) and enabled the synthesis of the C-silylated derivatives with monocyclic, silyl-bridged or fused tricyclic structures. Reactivity studies performed with N,N-dimethyl-4,5-bistrimethylsilylimidazole-2-thione as a model substance showed surprisingly stable silicon-vinyl bonds and reactivity patterns closely related to those observed for the unsilylated species 1 . Combined UV-spectroscopic and computational studies revealed only minor impact of the silyl substituents on the electronic structure of the imidazol-2-thione ring.