Selective sulfoxidation with hydrogen peroxide catalysed by a titanium catalyst

Abstract

A cyclopentadienyl–silsesquioxane titanium complex efficiently catalyses the selective oxidation of sulfides to sulfoxides (85–98% yield in 5 min at ambient temperature) and sulfones with near-stochiometric amount of aqueous H2O2 in methanol.

Stereospecific Synthesis of Chiral Titanium Complexes Bearing a Bifunctionalized Cyclopentadienyl-Terpenoid Ligand Derived from α-Pinene

“…The structures of these complexes were deduced by multinuclear NMR spectroscopy ( 1 H, 13 C, 19 Si, and 15 N) and elemental analysis and confirmed by single-crystal X-ray diffraction studies carried out on complex 1. The spectroscopic behavior of 1 and 2 is in accordance with the C 1 symmetry of the proposed structures, as inferred from the diastereotopic methyl groups on the silyl moiety and an ABCD or ABC spin system at low field for the nonequivalent Cp protons, respectively, in 1 and 2.…”

“…The obvious differences are due to the presence of the set of resonances derived from the chlorine-replacing group. For complex 3, the more relevant spectroscopic feature is the downfield shift for the fluorine atoms of the triflate group (at −77 ppm), in the 19 F NMR spectrum, that points to a covalently bound OTf ligand. 42 For 4 and 5, both the 1 H and 13 C{ 1 H} NMR spectra show the expected resonances for the respective alkyl substituents.…”

Schiff base complex conjugates of bovine serum albumin as artificial metalloenzymes for eco-friendly enantioselective sulfoxidation

“…30 Schiff base compounds have been extensively exploited as ligands for mono-or multinuclear macrocyclic or macroacyclic metal complexes, which are useful as biomimetic catalysts 31 in sulfoxidation. 30,[32][33][34][35][36] In particular, the use of transition metal complexes as catalysts, 37 mainly based on titanium, 38,39 vanadium, 40,41 manganese, 42,43 and iron, 44,45 is an area of current interest. 46,47 Serum albumins, the most abundant blood proteins in mammals, are globular, water-soluble, un-glycosylated transport proteins.…”

Suitable Approach to Prepare N‐Substituted Niobium Complexes – Study of the Factors Controlling the Process

“…Recent decades have witnessed an increasing interest in the chemistry of transition‐metal compounds carrying supporting polydentate ligands owing to the robustness and stability that the complexes demonstrate under catalytic conditions . Among these, it is worthy to highlight the ansa ‐cyclopentadienyl–silylamido complexes (constrained‐geometry complexes, CGCs), which have been studied extensively as successful alternative catalysts to the classical α‐olefin polymerization systems .…”