N-methylmorpholine N-oxide (NMO) in conjunction with catalytic amounts of RuCl3 oxidizes unsaturated alcohols and primary alcohols selectively to the corresponding aldehydes. Kinetic studies indicate that the order with respect to NMO and catalyst is one. The order with respect to the substrate is variable, being zero at high concentrations and fractional at low concentrations. The proposed mechanism involves the rate-determining formation of an adduct between the alcohol and Ru(V). The activation parameters, determined under zero-order conditions with respect to the substrate, pertain to the formation of RuVO species from RuCl3 and NMO. © 1990.

Joseph C. Kuriacose

ALDEHYDES--SYNTHESIS

CATALYSTS--SELECTIVITY

Chemical Reactions--Reaction Kinetics

PRIMARY ALCOHOLS

UNSATURATED ALCOHOLS

alcohols

IIT Madras is a public technical and research university located in Chennai, Tamil Nadu. Founded in 1959, it is recognised as an Institute of National Importance.

IIT Madras has been ranked as the top engineering institute in India for four years in a row by the National Institutional Ranking Framework of the MHRD

It currently offers undergraduate, postgraduate and research degrees across 16 disciplines in Engineering, Sciences, Humanities and Management. About 596 faculty belonging to science and engineering departments and centres of the Institute are engaged in teaching, research and industrial consultancy.

IIT Madras

Selective oxidation of unsaturated alcohols and primary alcohols by RuCl3/lv-methylmorpholine n-oxide (NMO) system: a kinetic study

Journal of Molecular Catalysis

Oxidation of dibutylsulfide, diphenylsulfide, methylphenylsulfide and dibenzylsulfide to the corresponding sulfoxides by N-methylmorpholine N-oxide (NMO) catalyzed by RuCl2(PPh3)3 in DMF solvent is reported. The reaction is first order in both catalyst and N-oxide. The order with respect to the substrate is variable, being zero at higher concentrations and fractional at lower concentrations. The order of reactivity observed for the substrates is as follows: dibutylsulfide ≈ dibenzylsulfide &gt; methylphenylsulfide &gt; diphenylsulfide. RuCl2(PPh3)3 oxidizes olefins to form epoxides at a slower rate. The order of reactivity observed for the two types of substrates parallels their nucleophilicity (sulfides &gt; alkenes). Spectral studies indicate 1:1 complex formation between RuCl2(PPh3)3 and the sulfides. The active oxidant is the Ru(IV)oxo complex formed by the oxidation of Ru(II) by NMO. © 1989.

Kinetics and mechanism of RuCl2PPh3)3-catalyzed oxidation of sulfides by N-methylmorpholine N-oxide

A catalytic amount of RuCl3 in the presence of excess of N-methyl-morpholine N-oxide (NMO) in DMF oxidizes secondary alcohols to ketones. Spectral studies reveal the formation of a Ru(V)-oxo species which is formed in situ on adding N-oxide. The formation of Ru(V) has been established by cyclic voltammetric studies. The mechanism involves the formation of Ru(V)-oxo species in steady state concentrations from Ru(III) and NMO, and this in turn reacts with the substrate in the rate-determining step. © 1987.

Ruthenium(III)-catalysed oxidation of secondary alcohols by N-methylmorpholine N-oxide (NMO)

Electronic, EPR and IR spectral evidence are given for the formation of the following active species: (1) ruthenium(VIII) in ruthenium(III)-PIA system, (2) ruthenium(V) oxo species in ruthenium(III)-N- oxide system, and (3) ruthenium(II)-phosphine oxide complex in ruthenium(II) N-oxide system. Cyclic voltammetric studies also suggest the formation of Ru(V) in ruthenium(III)-N-oxide system. © 1986.

Inorganica Chimica Acta

Spectral evidence for the formation of active intermediates from RuCl3 and RuCl2(PPh3)3 with N-methylmorpholine N-oxide (NMO) and phenyliodosoacetate (PIA) as mild oxidants

Journal	Journal of Molecular Catalysis
ISSN	03045102
Open Access	No