02328nas a2200241   4500008004100000022001400041245010400055210006900159260007300228300001200301490000800313520142900321653002201750653002401772653002601796653002201822653001501844100002401859700002301883700002801906700002301934856012901957       2008                        eng d  a1381-116900aSelective cis-dihydroxylation of olefins using recyclable homogeneous molybdenum acetylide catalyst0 aSelective cisdihydroxylation of olefins using recyclable homogen  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcAPR  a111-1190 v2853 a<p>Selective cis-dihydroxylation of various olefins has been carried out using molybdenum acetylide complex CpMO(CO)(3)(C CPh) (1) as catalyst and hydrogen peroxide as an efficient and environmentally benign oxidant. In case of cyclohexene, very high conversion (95%) and selectivity (86%) for cis-dihydroxylated product has been achieved using H2O2 as an oxidant and t-butanol as a solvent. cis-Dihydroxylation of other substrates like styrene, a-methyl styrene, limonene and cyclopentene has also been carried out with very high selectivity for diol. The catalyst and intermediate species have been characterized using FT-IR, UV-vis spectral analysis and XPS studies as well as cyclic voltametric studies. These studies suggest that molybdenum oxo-peroxo complex is the catalytically active species. The intermediate blue complex when characterized by ESI MS suggested the formation of dimeric molybdenum complex and XPS and cyclic voltametric studies confirm the presence of mixed valence Mo(V) and Mo(VI) in the reaction intermediate. Based on the characterization results possible mechanism for dihydroxylation is proposed. Interestingly, even though the catalyst is homogeneous; it could be recovered quantitatively by extraction in aqueous phase and recycled five times without any appreciable loss in cyclohexene conversion and selectivity for cis-1,2-cyclohexanediol. (c) 2008 Elsevier B.V. All rights reserved.</p>10aacetylide complex10acis-dihydroxylation10aHomogeneous catalysis10aHydrogen peroxide10arecyclable1 aBiradar, Ankush, V.1 aSathe, Bhaskar, R.1 aUmbarkar, Shubhangi, B.1 aDongare, Mohan, K.  uhttps://library.ncl.res.in/content/selective-cis-dihydroxylation-olefins-using-recyclable-homogeneous-molybdenum-acetylide-0