Oxidative Double Bond

Oxidative cleavage of carbon-carbon double bonds has emanated as one of the most challenging and attractive processes which have a tremendous potential in synthetic applications of modern organic chemistry,1 facilitating the formation of carbonyl compounds that widely occur in natural and synthetic bioactive molecules.2 The oxidative cleavage of C═C double bond reactions consists of cleavage of double bond associated with the insertion of oxygen into the C═C double bond to form aldehydes (Scheme 1), whereas over-oxidation of aldehydes may produce carboxylic acids. Among various oxidants such as H2O2, O2, oxone, PhI(OAc)2, TBHP etc., used, choice of NaIO4 as an oxidant due to easily soluble in water and cheapest one which leads most of the fundamental

The use of catalytic amounts of ruthenium complexes in the oxidative cleavage of olefinic double bonds improves selectivity towards the cleavage products, while preventing side reactions such as epoxidation, dihydroxylation, and allylic oxidation. The ligand coordinated to the metal plays a major role in improving the catalytic activity as well as the selectivity of the catalyst. In particular, a highly selective oxidative cleavage of styrene by O2 has been achieved by the catalytic amounts of [RuCl(DPP)2]ClO4, or trans-[RuCl2(DPP)2] (DPP = 1,3-bis(diphenylphosphino)propane) under mild conditions.20 Eduardo Peris et al. have documented catalytic performance of Ru(CNC)(CO)Br2 (A) complex towards the oxidative cleavage of olefins with 1 mol % of catalyst loading for 24 h.21 Shoair and co-workers have described the oxidative cleavage of alkenes to acids with IO(OH)5 as the co-oxidant using cis-[RuCl2(bipy)2].2H2O as a catalyst.22 The oxidative cleavage of olefins by [RuII(dmp)2(H2O)2]2+ (B) (dmp =2,9-dimethylphenanthroline) using H2O2 as the oxidant in CH3CN at 55 °C was developed by Ronny Neumann and co-workers.23 Bera and co-workers have explored Ru(II) based abnormal NHC catalysts (C) were found to be a highly active one for oxidative scission of olefins to aldehydes with 1 mol % up to 100% conversions within 30 min.24 Recently, Friedrich et al. have reported new (η5-Cyclopentadienyl) dicarbonylruthenium(II) amine complexes (D) (2.5 mol%) for styrene oxidation using CH3CN/H2O as a solvent system at 60°C.25a Though several ruthenium complexes have been shown to promote this transformation, quite a new catalyst is still required to rectify the drawbacks such as high temperature, long reaction time and high catalyst