[MoO3(2,2′–bipy)]n catalyzed oxidation of amines and sulfides

Abstract

The polymeric catalyst [MoO 3 (2,2′-bipy)] n has been employed in the oxidation of secondary amines to nitrones, and sulfides to sulfoxides or sulfones, using tert-butylhydroperoxide (TBHP) as the stoichiometric oxidant. Whereas the oxidation of amines occurs with less proficiency with respect to other previously studied polymeric Mo catalysts, the oxidation of sulfides occurs in high yield and selectivity. The catalyst is flexible in terms of substrate scope (aromatic, aliphatic and cyclic sulfides, thioheterocycles such as dimethyldibenzothiophene, the oxidation of which forms the basis of oxidation/separation processes for the desulfurization of fuels) and the ability to switch sulfoxide/sulfone product selectivities by adjusting the reaction conditions.

Catalytic activity of a new dioxidomolybdenum(vi) complex with a bipodal N2O-donor ligand in sulfur compound oxidation

“…[10][11][12][13][14][15] Industrially, molybdenum-based materials and complexes are widely applied in plenty of oxidation reactions, hydrocarbon dehydrogenations, polymerization reactions and alkene metatheses. 16,17 Moreover, an increase in recent studies involving molybdenum complexes applied in the oxidative desulfurization (ODS) process is observed. 18 The desulfurization of fuels is the second most important for the petrochemical industry.…”

“…22,28,29 In this context, sulfide oxidation takes place with good results to produce sulfoxides and sulfone. 6,13,16,30 In general, these molybdenum(VI) complexes contain the dioxidomolybdenum(VI) unit and are N,O,S-coordinated by Schiff base (imine) ligands. This group of ligands stabilizes diverse metal ions in different oxidation states and influences their performance as catalysts in a plenty of chemical transformations.…”

“…22,28,29 In this context, sulfide oxidation takes place with good results to produce sulfoxides and sulfone. 6,13,16,30…”

High-yield synthesis and catalytic response of chainlike hybrid materials of the [(MoO3)m(2,2′-bipyridine)n] family

“…14 The oxidative decarbonylation of molybdenum carbonyl complexes under mild conditions has proved to be a particularly useful technique and, in the case of the tetracarbonyl complex cis-[Mo(CO) 4 (2,2'bipy)], allowed the isolation of [MoO 3 (2,2'-bipy)] (1) in nearquantitative yield. 14a Polymeric 1 has given interesting results as a catalyst for the epoxidation of olefins, 14a the oxidation of secondary amines to nitrones, 15 and the oxidation of sulfides to sulfoxides or sulfones. 15 The existence of the bipy-deficient derivatives of 1 provides a potential avenue for systematically studying structure-performance relationships with respect to the use of the compounds in catalysis.…”

“…14a Polymeric 1 has given interesting results as a catalyst for the epoxidation of olefins, 14a the oxidation of secondary amines to nitrones, 15 and the oxidation of sulfides to sulfoxides or sulfones. 15 The existence of the bipy-deficient derivatives of 1 provides a potential avenue for systematically studying structure-performance relationships with respect to the use of the compounds in catalysis. With this in mind, we sought improved syntheses of these hybrid materials to make them readily available for catalytic investigations.…”