An efficient route to alkyl chlorides from alcohols using the complex TCT/DMF

[reaction: see text] Efficient conversion of alcohols and beta-amino alcohols to the corresponding chlorides (and bromides) can be carried out at room temperature in methylene chloride, using 2,4,6-trichloro[1,3,5]triazine and N,N-dimethyl formamide. This procedure can also be applied to optically active carbinols.     

DMSO-catalyzed chlorination of alcohols using N-phenylbenzimidoyl chloride

N-phenylbenzimidoyl chloride has been demonstrated as an efficient chlorination reagent catalyzed by dimethyl sulfoxide (DMSO) in conversion of alcohols to corresponding chlorides. The reaction conditions were mild, and most of the substrates gave satisfactory yields. The configuration inversion of the chlorination was proved using optically active phenyl alcohols. The amount of DMSO can be as low as 0.001 eq without reducing the efficiency of the chlorination. A plausible mechanism for the reaction was proposed and proved by experiments. The reaction is stereoselective and potentially chemoselective among primary benzyl alcohols, secondary benzyl alcohols, and unactivated aliphatic alcohols.     

NMP-mediated chlorination of aliphatic alcohols with aryl sulfonyl chloride for the synthesis of alkyl chlorides

NMP-mediated chlorination of aliphatic alcohols has been developed for the synthesis of alkyl chlorides. This facile, efficient and practical approach used simple and readily available aryl sulfonyl chlorides as the chlorination reagent for the construction of C–Cl bond in good to excellent yields with mild conditions and broad substrate scope.     

Action of water and alcohols on acid chlorides in the gaseous state

Conclusions The esterification and hydrolysis of a number of acid chlorides (dimethyldichlorosilane, SiCl₄, acetyl chloride) fail to go when they are treated with water or with alcohols in the gas phase.Deceased.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 6, pp. 1332–1334, June, 1973.     

乙醇的低温光催化氧化实验研究

利用傅里叶变换红外光谱仪(FT-IR),在间歇式反应器中研究了高浓度乙醇的低温光催化氧化特性。研究结果表明,FT-IR技术能够用来研究气态有机物的光催化降解特性;在乙醇的光催化降解过程中,有乙醛等中间产物生成,乙醇先被氧化为乙醛,再被氧化为二氧化碳;在间歇式反应器中,乙醇的循环流量对乙醇的瞬时降解速率影响不大;高浓度乙醇的低温光催化氧化过程可以用单步Langmuir-Hinshelwood 方程来描述;温度对乙醇光催化氧化的初始反应速率的影响十分显著,高浓度乙醇的初始反应速率随温度的升高而迅速提高。     

An efficient method for chlorination of alcohols using PPh3/Cl3CCONH2

A new and convenient method for the chlorination of alcohols utilizing PPh₃/Cl₃CCONH₂ is addressed. Various alcohols could smoothly be converted into their corresponding alkyl chlorides in high yield under mild conditions with short reaction times. A mechanism is disclosed with the evidence of inversion of configuration of the analogous alkyl chloride derived from R-(−)-2-octanol.     

Trichloroisocyanuric/TEMPO oxidation of alcohols under mild conditions: a close investigation

Efficient oxidation of primary alcohols to the corresponding carboxylic acids can be carried out at room temperature and in acetone/water, using trichloroisocyanuric acid (TCCA) in the presence of catalytic TEMPO. The mild conditions of this procedure and the total absence of any transition metal make this reaction suitable for safe laboratory use. A possible mechanism is presented and discussed.     

Self-exchange electron transfer in high oxidation state non-oxo metal complexes: amavadin

The electron transfer self-exchange rate constant between the oxidized and reduced forms of amavadin equals approximately 1 x 10(5) dm3 mol(-1) s(-1) at 25 degrees C and represents the first unambiguous example for a vanadium(IV/V) couple.     

Equilibrium distribution coefficients of some metal chlorides in sodium chloride

Conclusions The method of directed crystallization of the melt was used to determine the distribution coefficients of In Cl₃, SnCl₂, SbCl₃, LaCl₃, IrCl, and AuCl in NaCl in the region of microconcentrations of the contaminant.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 4, p. 929, April, 1973.     

Microwave-assisted oxidation of alcohols using Magtrieve™

Primary and secondary alcohols can be selectively oxidized under microwave irradiation into the corresponding aldehydes and ketones within 5-30 min using commercially available and magnetically retrievable Magtrieve™.     

Correlation of the reactivity of organoelement chlorides in metal oxidation in aprotic media

The reactivity of RMCl compounds [RM = Cp(CO)₃Mo, Cp(CO)₃W, Cp(CO)₂Fe, Cp(PPh₃)Ni, and Ph₂Bi] used as oxidants in reactions with metals in aprotic media was assessed to establish that the electron density of the metal atom in the RM group is linearly related to the total electronegativity of this group. The resulting electron densities correlate with the log rate constants of magnesium oxidation with the RMCl compounds in DMF. The reactivity of the oxidants in the organometallic chloride-compact metal-solvent system is a function of the physicochemical properties of the medium.     

Shape-selective oxidation of primary alcohols using perruthenate-containing zeolites

Potassium perruthenate (KRuO4), a known, effective oxidant for the conversion of primary and secondary alcohols into carbonyl compounds is impregnated into zeolite X and shown to be a shape-selective oxidant using benzyl alcohol (reacted) and pyrenemethanol (not reacted).     

Indium-catalyzed direct chlorination of alcohols using chlorodimethylsilane-benzil as a selective and mild system

The InCl3-catalyzed reaction of alcohols with chlorodimethylsilane (HSiMe2Cl) in the presence of benzil gave the corresponding organic chlorides under mild conditions. Benzil significantly changes the reaction course because the reducing product through dehydroxyhydration was obtained in the absence of benzil. The secondary or tertiary alcohols were effectively chlorinated. The substrates bearing acid-sensitive functional groups were also applied to this system. The highly selective chlorination of the tertiary site was observed in the competitive reaction between tertiary and primary alcohols. The highly coordinated hydrosilane generated from benzil and HSiMe2Cl is an important intermediate.     

Raman-spectrum investigation of some acetylenic alcohols and their acetic esters

Summary The formation of the acetic esters of tri- and di-bromo ketols by the action of HOBr on the acetic esters of secondary and tertiary acetylenic alcohols is due to the particularly strongly protonized (acidic) hydrogen atom of the methylidyne group=C-H, which results from profound frequency modulation of the vibrations of the latter by the low-frequency intermolecular vibrations at the hydrogen bonds.     

Kinetics and mechanism of oxidation of some alcohols by osmium tetroxide

Spectrophotometric studies of the kinetics of oxidation of 2-methylpropan-1-ol and 2-butanol by an alkaline solution of osmium tetroxide have been reported. A first-order dependence to osmium tetroxide was observed. A first-order dependence to both 2-methylpropan-1-ol and alkali at low concentration tends to zero order at higher concentrations. In the case of 2-butanol, first-order kinetics is exhibited with respect to 2-butanol but first-order kinetics observed at lower concentrations of alkali decrease at higher concentrations. A negligible ionic strength effect of the medium was observed. Activation parameters have been computed. A suitable mechanism in conformity with our kinetic observations has been suggested.     

The oxidation of some enamines with metal oxidants

4-(1-cyclohexen-1-yl)-morpholine, 1-morpholino-styrene and 1-morpholino-2-methyl- styrene were treated with lead tetraacetate. The products obtained were N-acetyl-morpholine, the 2-acetoxy-ketone and in the case of the first substrate its enamine. The 2-morpholino-ketone was also formed in the reactions with 4-(1-cyclohexen-1-yl)-morpholine and 1-morpholino-2-methylstyrene. 4- (1-cyclohexen-1-yl)-morpholine reacted with thallium triacetate and mercuric diacetate, giving very similar results. A mechanistic scheme is discussed, where an intermediate product derived from the addition of two acetoxy groups to the enamine double bond is cleaved via an α-elimination path.     

Metal-free oxidation of secondary benzylic alcohols using aqueous TBHP

We report a simple, yet efficient metal-free oxidation of secondary benzylic alcohols in the presence of t-butyl hydroperoxide (70% TBHP) with high yields of up to 98%. This type of reaction can be carried out using a wide variety of substrates, requires no other organic solvent, and proves to be tolerant toward a variety of different functional groups.     

Liquid phase oxidation of alcohols with oxygen: in situ monitoring of the oxidation state of Bi-promoted Pd/Al2O3

In situ, time-resolved XAS studies on a Bi-Pd/Al2O3 catalyst indicate that Pd, and Bi located on the Pd surface, are in a reduced, metallic state during the oxidation of 1-phenylethanol with molecular oxygen--a key for understanding the role of promoter in the reaction mechanism.