ABSTRACT
A survey of several metavandate (VO3(-)) and chelated dioxovanadium derivatives shows that tetrabutylammonium dioxovanadium(V)dipicolinate most effectively catalyzes the deoxydehydration (DODH) of glycols to olefins in moderate to excellent yields with triphenylphosphine or sodium sulfite as reductants.
Subject(s)
Alkenes/chemical synthesis , Glycols/chemistry , Organometallic Compounds/chemistry , Vanadium/chemistry , Alkenes/chemistry , Catalysis , Dehydration , Molecular StructureABSTRACT
Methyltrioxorhenium and sodium perrhenate catalyze the deoxydehydration of glycols and deoxygenation of epoxides to olefins in moderate yields with sulfite as the reductant.
Subject(s)
Glycols/chemistry , Organometallic Compounds/chemistry , Rhenium/chemistry , Sulfites/chemistry , Alkenes/chemical synthesis , Alkenes/chemistry , Catalysis , Dehydration , Epoxy Compounds/chemistry , Molecular Structure , Oxidation-ReductionABSTRACT
The mechanism of oxidation of ArSO(2)(-) (PhSO(2)(-) and 5-sulfinato-2-nitrobenzoic acid = TNBO(2)(1-/2-)) with HOCl/OCl(-) has been investigated using the kinetic method. In contrast to previous reports for PhSO(2)(-) (for which it was suggested that OCl(-) and not HOCl was the reactant), the reaction proceeds through a conventional pathway: nucleophilic attack by ArSO(2)(-) on HOCl with concomitant Cl(+) transfer to give a sulfonyl chloride intermediate (ArSO(2)Cl), which we have identified spectrophotometrically. Remarkably, the rate constant for the reaction of HOCl with ArSO(2)(-) is on the order of 10(9) M(-1) s(-1), larger than the rate constants for corresponding thiolates, and is nearly diffusion-controlled. In contrast, the rate constant for the reaction of OCl(-) with ArSO(2)(-) is approximately 7 orders of magnitude smaller.
