Aqueous Tert Research Articles

Novel dicopper(II)-tetracarboxylates as catalysts for selective oxidation of benzyl alcohols with aqueous TBHP

Abstract A few dicopper(II) tetracarboxylate complexes viz. [Cu 2 (µ-O 2 CC 6 H 5 ) 4 (4-Etpy) 2 ] ( 1 ), [Cu 2 (µ-O 2 CC 6 H 5 ) 4 (4-DMAP) 2 ] ( 2 ), [Cu 2 (µ-O 2 CC 6 H 5 ) 4 (4-CNpy) 2 ] ( 3 ) and [Cu 2 (µ-O 2 CCH 3 ) 4 (4-CNpy) 2 ] ( 4 ) have been utilised as catalysts for oxidation of benzyl alcohols using aqueous tert -butyl hydroperoxide as the oxidant. Complexes 1 and 2 have shown better catalytic activity than the other two. Unlike other catalysts, these dicopper complexes can catalyse oxidation of alcohols at a very low concentration (0.5 mol%).

Asymmetric epoxidation of alkenes with tert-butyl hydroperoxide catalyzed by a novel chiral complex of manganese(III) containing a sugar based tridentate Schiff-base ligand

Abstract The [Mn III ( TDL 1 ∗ )(pic)(H 2 O)] ( 1 ) complex (where H 2 TDL 1 ∗ = N -3,5-di-( t -butyl)salicylidine- d -glucosamine, pic − = picolinate) had been synthesized and characterized by analytical, spectral (UV–vis and IR), molar conductivity, magnetic moment and electrochemical studies. Complex 1 efficiently catalyzed the epoxidation of styrene, 4-chlorostyrene, 4-methylstyrene, 4-methoxystyrene, 1-methylcyclohexene and 1,2-dihydronaphthalene using aqueous tert -butyl hydroperoxide ( t -BuOOH) as terminal oxidant. The selected alkenes were effectively converted to their organic epoxides in the 50–62% enantiomeric excess(ee) at ambient temperature.

A New and Highly Efficient Water‐Soluble Copper Complex for the Oxidation of Secondary 1‐Heteroaryl Alcohols by tert‐Butyl Hydroperoxide.

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Chromium(VI) oxide-catalysed oxidations by tert -butyl hydroperoxide using benzotrifluoride as solvent

Abstract Chromium(VI) oxide-catalysed oxidations of alcohols and activated methylenes by aqueous tert -butyl hydroperoxide have been studied using benzotrifluoride as solvent. Comparisons with previous studies showed that this solvent is a valuable alternative to methylene chloride for such reactions. © 2000 Academie des sciences / Editions scientifiques et medicales Elsevier SAS

ChemInform Abstract: A Method for Reductive Cleavage of N‐Glycosylamide Carbohydrate‐Peptide Bond.

Abstract A new, mild method for the splitting of N -linked oligosaccharides from glycoproteins includes treatment of glycoproteins (ovomucoid, flavoprotein, ribonuclease B, hemagglutinin, or transferrin) with 2 m LiBH 4 in 25m m LiOH-50m m Li citrate-70% aqueous tert -butyl alcohol (5 h, 45°), followed by hydrolysis of the resulting glycosylamine with aqueous acetic acid. The oligosaccharides formed were easily isolated by gel filtration and cation-exchange chromatography in 60–80% yields. The reaction was accompanied by the intense reductive cleavage of peptide bonds with formation of amino alcohols, but N -deacetylation of hexosamine was completely excluded. The optimal conditions of this reaction were chosen by use of a model glycopeptide, 2-acetamido-4- O -(2-acetamido-2-deoxy-β- d -glucopyranosyl)-1- N -(4- l -aspartoyl)-2-deoxy-β- d -glucopyranosylamine.