Reactions with N-Carbonylsulfamoyl Chloride

N-Carbonylsulfamoyl chloride (NCSA) is an intermediate that can be obtained from cyanogen chloride and sulfur trioxide, and which reacts with many compounds, via electrophilic substitution, much more readily than other isocyanates. Reactions with compounds containing hydroxyl, amino, or carboxyl groups lead to N-chlorosulfonylurethanes, -ureas, and -amides, respectively. This group of products also includes the parent substance sulfamoyl chloride (amidosulfonyl chloride). The reaction of N-carbonylsulfamoyl chloride with olefins provides an easy route, not only to derivatives of β-amino acids and unsaturated carboxylic acids, but also to many β-lactams. New, very reactive sulfonylisocyanates of several types can be obtained by further reactions of primary products obtained from N-carbonylsulfamoyl chloride and by the reaction of N-carbonylsulfamoyl chloride with olefins in the presence of free-radical formers. When allowed to react with a number of compounds, NCSA undergoes loss of carbon dioxide to form products containing the grouping = N? SO₂Cl.     

Dimethyl sulfoxide/oxalyl chloride: A useful reagent for sulfenyletherification

A facile method for the sulfenyletherification of unsaturated alcohols using dimethyl sulfoxide/oxalyl chloride has been described in this article. Methanesulfenyl chloride is supposed to be the compound responsible for the sulfenyletherification, which is generated by the reaction of oxalyl chloride with 2 equivalents of dimethyl sulfoxide. The formation pathway of methanesulfenyl chloride is discussed based on the formation of cyclic acetals.     

Gas Phase Conversion of Carbon Tetrachloride to Alkyl Chlorides Catalyzed by Supported Ionic Liquids

An efficient way of converting carbon tetrachloride (CTC) to alkyl chlorides is reported, which uses the catalysts of ionic liquids supported on granular active carbon. The catalytic performance was evaluated in a temperature range of 120–200°C and atmospheric pressure for different ionic liquids, namely 1‐butyl‐3‐methylimidazolium chloride, 1‐octyl‐3‐methylimidazolium chloride, hydrochloric salts of N‐methylimidazole (MIm), pyridine and triethylamine, as well as bisulfate and dihydric phosphate of N‐methylimidazole. On this basis, the reaction mechanism was proposed, and the influences of the reaction temperature and the attributes of ionic liquids were discussed. The overall reaction was assumed to be comprised of two steps, the hydrolysis of CTC and reaction of HCl with alcohols under acidic catalyst. The results indicate that the conversion of CTC increased monotonically with temperature and even approached 100% at 200°C, while the maximum selectivity to alkyl chlorides was obtained around 160°C. This reaction might be potentially applicable to the resource utilization of superfluous byproduct of CTC in the chloromethane industry.     

Characterisation of ethoxylated fatty chains of anionic surfactants and determination of residual ethoxylated fatty alcohols

Bachus et al. [1] recently described a new derivatisation method using 2-furoyl chloride for the characterisation of mixtures of polyethoxylated alcohols and their corresponding sulfates. This paper deals with the control of the derivatisation steps; hydrolysis and extraction conditions were optimised. The method is extended to the characterisation of alkyl sulfosuccinates, alkyl sulfoacetates and alkyl phosphates and to the analysis of residual polyethoxylated alcohols in surfactants. Extraction of non-ionic compounds using solid-phase extraction cartridges was performed before derivatisation. Residual amounts of alcohol were determined in five commercial anionic surfactants. Moreover, direct derivatisation without preliminary SPE in the same anionic surfactants proved to be efficient for dry samples.     

Oxidation of alcohols by “activated” dimethyl sulfoxide. a preparative,steric and mechanistic study

The oxidation of primary, secondary, allylic, benzylic, hindered and bicyclic alcohols with dimethyl sulfoxide (DMSO) “activated” by numerous electrophiles was studied: yields of carbonyls, by-products and recovered alcohols were quantitatively determined. Pathways for carbonyl and by-product formation are presented. Generally, yields of carbonyls increase with increased steric hindrance in the alcohols. Steric effects of tertiary amines, used for basification, were also investigated, and the results are consistent with the suggested reaction pathways. Among previously unreported “activators,” oxalyl chloride is the most generally effective; yields of carbonyls are typically over 95%. Thionyl chloride is also a satisfactory “activator” although yields of carbonyls are not quite as high. An improved method of preparation of alkyl methylthiomethyl ethers, by-products of the oxidation process, is reported.     

Chemoselective and scalable preparation of alkyl tosylates under solvent-free conditions

The improved method for the efficient tosylation of alcohols has been reported using two procedures (A and B). Procedure A: methanol, ethanol, benzyl alcohols, and valuable ethylene glycols can be converted into their corresponding alkyl tosylates in very fast, simple, and efficient grinding method using potassium carbonate as solid base. Other primary and secondary alcohols need to add potassium hydroxide to reaction mixture (procedure B). High selectivity of tosylation was observed for these two procedures. Scale up ability was found in this method even in 100 mmol of substrate. The present method is the example of solid-state tosylation using tosyl chloride, and is a green chemical process due to solvent-free conditions.     

Fluorous scavenger for parallel preparation of tertiary sulfonamides leading to secondary amines

Alkylation of secondary sulfonamides by alkyl halides or alcohols (Mitsunobu reaction) is an efficient method for secondary amines preparation. However, its application to parallel chemistry is often difficult due to partial reaction. In this Letter, we propose a fluorous technique to bypass this problem. Thus, o-nitrobenzenesulfonamides were prepared and alkylated in parallel (Fukuyama method) with various alkyl halides or alcohols. Depending on the nature of the alkyl halide or alcohol, this step remained incomplete. A reactive fluorous alkyl iodide was then used to trap the unreacted sulfonamide allowing for a rapid and efficient fluorous solid-phase extraction (FSPE). Some examples of the isolated tertiary sulfonamides were converted in parallel to the corresponding secondary amines with good purity.     

Cationic polymerization of styrene involving ionization of the C?Cl bond in ionic liquid/SO2 mixture

There has been a recent upsurge in interest in use of ionic liquids as reaction media for various chemical processes. Until recently, ionic liquids were considered as highly polar solvents. Our earlier investigation indicated that cationic polymerization of styrene initiated by aryl (alkyl) chlorides in ionic liquids may proceed even in the absence of coinitiator (Lewis acid). Polymerization, however, did not conform to controlled polymerization scheme. More recently, it has been claimed that ionic liquids are not as polar as it was previously assumed. Independently, high solubility of sulfur dioxide in ionic liquids was noticed. As sulfur dioxide displays a high ionizing power toward organic halides, we applied ionic liquid/sulfur dioxide mixture as a solvent in cationic polymerization of styrene initiated by aryl (alkyl) chlorides. Results show that in this reaction medium ionization of the C? Cl bond is facilitated, and the contribution of chain transfer reaction can be reduced as compared with polymerization in ionic liquid alone. Ionization of the C? Cl bond, however, is still not sufficiently fast to ensure conditions of controlled polymerization. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 5251–5257, 2009     

Features of catalysis in the reaction of polyfluoroalkyl chlorosulfites with saturated monohydric alcohols

Synthetic opportunities and mechanism of catalysis of the reaction of polyfluororalkylchlorosulfites with saturated monohydric alcohols are considered. Kinetic measurements and quantum-chemical calculations showed that polyfluoroalkylation of these compounds proceeded through the step of complex formation involving reagents and catalyst followed by liberation of hydrogen chloride and sulfur dioxide and formation of polyfluoroalkyl ethers.     

1,1‐Disilyl Alcohols as d1 Synthons: Harnessing the 1,2‐Brook Rearrangement

1,1‐Disilyl alcohols like 6 give the silyl ethers like 9 on treatment with base and alkyl halides, in a reaction which may be formulated as the alkylation of the Brook‐rearranged carbanion 8 . The products can be oxidised to give ketones like 10 , showing that this Brook‐rearranging system supplies a controlled d¹ synthon of the acyl anion class. The alcohols can be prepared from the acid chloride 12 and dimethyl(phenyl)silyllithium, but the intermediate anion 21 need not be worked up; it can be used directly in the alkylation step.     

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.     

烟气中二氧化硫及三氧化硫测定方法的研究

本文采用过氧化氢-氯化钡-钍试剂法以及80%异丙醇-氯化钡-钍试剂法分别测定了烟气中的二氧化硫及三氧化硫质量浓度,并对该方法的灵敏度、准确度以及各种影响因素进行了研究分析.本方法简单、快速、准确、便于现场监测控制.     

The solubility of sulfur dioxide in aqueous solutions of sodium chloride and ammonium chloride in the temperature range from 313 K to 393 K at pressures up to 3.7 MPa: experimental results and comparison with correlations

The solubility of sulfur dioxide in aqueous solutions of single solutes sodium chloride and ammonium chloride was measured using a static method at temperatures from 313 K to 393 K and total pressures up to 3.7 MPa corresponding to gas molalities of up to 10 mol/kg. Similarily to the system sulfur dioxide–water, also in systems with sodium and ammonium chloride a second (sulfur dioxide-rich) liquid phase is observed at high sulfur dioxide concentrations. A model to describe the phase equilibria is presented. Experimental results are reported and compared to correlations.     

2-Pyridylsulfinamides as effective catalysts in the asymmetric alkylation of aldehydes with diethylzinc

Chiral 2-pyridylsulfinamides were shown to be effective catalysts in the alkylation of aryl and alkyl aldehydes with diethylzinc providing the corresponding alcohols in excellent enantioselectivity. Sulfinamide catalysts possessing solitary chirality at the sulfur center produced the product phenethyl alcohol in good enantioselectivity. Diastereomeric sulfinamides possessing chirality at the carbon-bearing nitrogen and at the sulfur of the sulfinamide increased the enantioselectivity of the product alcohols up to >99%. However, there is no effect of the match-mismatch pair of sulfinamide diastereomers on the outcome of the chiral induction of the product phenethyl alcohols. It was conclusively proved that chirality at the sulfur center is mandatory for obtaining good enantioselectivity in the reaction.     

二氧化硫与戊烷的气相光化学反应研究

Baclock等^[1]的研究表明,在SO2与烃的光化学反应体系中,单重态SO2通过系间窜跃转化为三重态SO2参与光化学反应,Penzhorn等^[2,3]的研究表明,在SO2与C4以下气相烃的光化学反应中有多种产物存在,产物的复杂性预示反应为自由基链反应。Smith等^[4]等认为体系中存在烃的逐步氧化,同时证明SO2与烷烃光化学反应中自由基链反应的重要性,文献报道的研究多以凝聚态产物为切入点^[5],为避免器壁对光化学反应的影响,本文以气相物质为研究对象,对挥发性烷烃中结构最简单的戊烷与二氧化硫的光化学反应的气相反应产物,反应机理和影响因素等进行了研究。     

Photoredox‐Catalyzed Functionalization of Alkenes with Thiourea Dioxide: Construction of Alkyl Sulfones or Sulfonamides

Sulfonylation of alkenes through photoredox‐catalyzed functionalization of alkenes with thiourea dioxide under visible‐light irradiation is achieved. The reaction of alkenes, thiourea dioxide and electrophiles provides a green and efficient access to alkyl sulfones and sulfonamides. A broad reaction scope is presented with good functional group compatibility and excellent regioselectivity. A plausible mechanism involving a radical addition process with sulfur dioxide radical anion (SO₂^‐) derived from the oxidation of sulfur dioxide anion (SO₂^2–) is proposed, which is supported by fluorescence quenching experiments.     

Photoinduced reaction of potassium alkyltrifluoroborates,sulfur dioxide and para-quinone methides via radical 1,6-addition

A photoinduced reaction of potassium alkyltrifluoroborates, sulfur dioxide, and para-quinone methides under visible light irradiation at room temperature is developed, giving rise to diarylmethyl alkylsulfones in moderate to good yields. This reaction works well under photocatalysis with a broad substrate scope by using DABCO·(SO₂)₂ as the source of sulfur dioxide. Mechanistic study shows that this transformation is initiated by alkyl radicals generated in situ from potassium alkyltrifluoroborates in the presence of photocatalyst. The subsequent insertion of sulfur dioxide and radical 1,6-addition of para-quinone methides with alkylsulfonyl radical intermediates afford the corresponding diarylmethyl alkylsulfones.     

Reaction kinetics of the reaction between carbon dioxide and glycidyl methacrylate using tetraoctylammonium chloride as catalyst

Carbon dioxide was absorbed in an organic solutions of glycidyl methacrylate (GMA) in a semi-batch stirred tank with a plane gas-liquid interface at 101.3 kPa to obtain the absorption rate of carbon dioxide, from which the reaction kinetics of the reaction between carbon dioxide and GMA as studied using tetraoctylammonium chloride as catalyst. The reaction rate constants were estimated from the mass transfer mechanism accompanied by the pseudo-first-order reaction with respect to the concentration of carbon dioxide. An empirical correlation formula between the reaction rate constants and the solubility parameters of solvents such as toluene, N-methyl-2-pyrrolidinone, and dimethyl sulfoxide is presented.     

Synthesis of photopolymers with pendant cyclic carbonate and cinnamic ester groups

Photopolymers with both pendant cyclic carbonate groups and cinnamic ester groups were synthesized by the addition reaction of poly(glycidyl methacryalte-co-styrene)[poly(GMA-co-AN)] with carbon dioxide and then with cinnamoyl chloride. Soluble quaternary ammonium salt catalysts showed good yield of cinnamoyl chloride addition to the glycidyl methacrylate groups. Quaternary salt catalysts of longer alkyl chain length and of more nucleophilic anion offered higher yield of cinnamoyl chloride addition. Photochemical reaction test showed that poly(CNMA-co-DOMA-co-St) had a good photosensitivity. This revised version was published online in June 2006 with corrections to the Cover Date.     

Studies on the Cu(I)-catalyzed regioselective anti-carbometallation of secondary terminal propargylic alcohols

A highly regioselective Cu(I)-catalyzed anti-carbometallation of secondary terminal propargylic alcohols with 1 degrees alkyl or aryl Grignard reagents affording 2-substituted allylic alcohols was developed. By using this method, optically active allylic alcohols can be prepared from the optically active propargylic alcohols without obvious loss of the enantiopurity. The cyclic organometallic intermediate formed may undergo an iodination or a Pd(0)-catalyzed coupling reaction to afford stereo-defined allylic alcohols.