The helical stability of poly-L-glutamic acid and poly-Lornithine in aqueous alcohol solutions was studied by optical rotatory dispersion and potentiometric titration determinations. It was found that aliphatic alcohols enhance the stability of the helix according to the series methanol < ethanol < I-propanol < I-butanol. The role of secondary and tertiary alcohols was also investigated. Thermo...

Acceptorless dehydrogenation of alcohols, an important organic transformation, was accomplished with welldefined and inexpensive iron-based catalysts supported by a cooperating PNP pincer ligand. Benzylic and aliphatic secondary alcohols were dehydrogenated to the corresponding ketones in good isolated yields upon release of dihydrogen. Primary alcohols were dehydrogenated to esters and lactone...

The direct trifluoromethylation of a variety aliphatic alcohols using hypervalent iodosulfoximine reagent afforded the corresponding ethers in moderate to good yields (14–72 %). Primary, secondary, and even tertiary alcohols, including examples derived from natural products, underwent this transformation presence catalytic amounts zinc bis(triflimide). Typical reaction conditions involved neat ...

The glycosylation reaction is the key transformation in oligosaccharide synthesis, but it is still difficult to control in many cases. Stereocontrol during cis-glycosidic linkage formation relies almost exclusively on tuning the glycosylating agent or the reaction conditions. Herein, we use nucleophile-directed stereocontrol to manipulate the stereoselectivity of glycosylation reactions. Placin...

It has been found that 2,7-di-tert-butylpyrene reacts with aliphatic iso(thio)cyanates in the presence of trifluoromethanesulfonic acid to exclusively afford the corresponding 1-substituted (thio)amides in high yields. For aromatic iso(thio)cyanates the reaction is less regioselective, although substitution at the 1-position prevails. For ethoxycarbonyl isothiocyanate, apart from the 1-substitu...

Three novel, bifunctional triazine-based ligands, namely , and , containing both a TEMPO and a bipyridine moiety have been synthesized. These bpy/TEMPO-based molecules have been used as catalyst precursors for the copper-catalyzed aerobic oxidation of alcohols to aldehydes and ketones, in the presence of tert-BuOK as co-catalyst. The complexes obtained in situ from ligands and with copper(II) b...

Single-bubble sonoluminescence (SBSL) in water has been studied in the presence of low concentrations of simple organic compounds. For a given concentration of aliphatic alcohol, the degree of quenching follows the order, ethanol< I -propanol< 1-butanol, Preliminary experiments with simple we& acids and bases indicate that SBSL quenching only occurs when the pH is adjusted such that the solutes...

A simple, efficient and highly diastereoselective one-pot three-component synthesis of functionalized 2,6-disubstituted-4-tosyloxytetrahydropyrans was performed. The synthesis features an optimized Prins cyclization in which an aromatic homoallylic alcohol, an aromatic/aliphatic aldehyde, and p-toluenesulfonic acid (catalyst and reagent) are reacted in the presence of molecular sieves (MS) 4 Å ...

An efficient and simple method for selective oxidation of secondary alcohols and oxidation of alkanes to ketones is reported. An in situ prepared catalyst is employed based on manganese(II) salts, pyridine-2-carboxylic acid, and butanedione, which provides good-to-excellent conversions and yields with high turnover numbers (up to 10 000) with H2 O2 as oxidant at ambient temperatures. In substra...

Monosubstituted cycloalkanes undergo regio- and enantioselective aliphatic C-H oxidation with H2O2 catalyzed by biologically inspired manganese catalysts. The reaction furnishes the corresponding ketones resulting from oxidation at C3 and C4 methylenic sites (K3 and K4, respectively) leading to a chiral desymmetrization that proceeds with remarkable enantioselectivity (64% ee) but modest regios...