Copper‐Catalyzed Reduction of Alkyl Triflates and Iodides: An Efficient Method for the Deoxygenation of Primary and Secondary Alcohols

We describe an effective method for catalytic reduction of 1° alkyl sulfonates, and 1° and 2° iodides in the presence of a wide range of functional groups. This Cu‐catalyzed reaction provides a means for the effective deoxygenation of alcohols, as demonstrated by the highly selective reduction of 1° alcohols using a triflation/reduction sequence. A preliminary study of the reaction mechanism suggests that the reduction does not involve free‐radical intermediates.     

A Facile Conversion of Tertiary Alcohols to Olefins

An efficient method for the dehydration of tertiary alcohols to obtain olefins in high yield, employing methanesulfonyl chloride-triethylamine and catalytic amount of 4-dimethylaminopyridine in dichloromethane, is described.     

A Facile Method for the Conversion of Primary Alkyl Chlorides to the Corresponding Bromides

Treatment of several representative primary alkyl chlorides with one equivalent of sodium bromide in 2:1 (v/v) N,N-dimethylformamide : dibromomethane at 100[ddot]C for several hours resulted in their quantitative conversion to the corresponding bromides.     

Reductive Cross-Coupling of a Vinyl Thianthrenium Salt and Secondary Alkyl Iodides

We report the first reductive vinylation of alkyl iodides. The reaction uses a vinyl thianthrenium salt, a palladium catalyst, and an alkyl zinc intermediate formed in situ to trap the L_nPd^II(vinyl) complex formed after oxidative addition before it undergoes undesired homocoupling to form butadiene.     

Manganese-Catalyzed Chemoselective Coupling of Secondary Alcohols,Primary Alcohols and Methanol

Herein, we report a manganese-catalyzed three-component coupling of secondary alcohols, primary alcohols and methanol for the synthesis of β,β-methylated/alkylated secondary alcohols. Using our method, a series of 1-arylethanol, benzyl alcohol derivatives, and methanol undergo sequential coupling efficiently to construct assembled alcohols with high chemoselectivity in moderate to good yields. Mechanistic studies suggest that the reaction proceeds via methylation of a benzylated secondary alcohol intermediate to generate the final product.     

A Facile Preparation of Methoxymethyl Ethers of Primary and Secondary Alcohols with Dimethoxymethane Catalysed by Expansive Graphite

An easy preparation of methoxymethyl ethers of primary and secondary alcohols with dimethoxymethane has been carried out in excellent yield under catalysis of expansive graphite.     

Cobalt‐Catalyzed Negishi Cross‐Coupling Reactions of (Hetero)Arylzinc Reagents with Primary and Secondary Alkyl Bromides and Iodides

We report a cobalt‐catalyzed cross‐coupling of di(hetero)arylzinc reagents with primary and secondary alkyl iodides or bromides using THF‐soluble CoCl₂?2 LiCl and TMEDA as a ligand, which leads to the corresponding alkylated products in up to 88 % yield. A range of functional groups (e.g. COOR, CN, CF₃, F) are tolerated in these substitution reactions. Remarkably, we do not observe rearrangement of secondary alkyl iodides to unbranched products. Additionally, the use of cyclic TBS‐protected iodohydrins leads to trans‐2‐arylcyclohexanol derivatives in excellent diastereoselectivities (up to d.r.=99:1).     

Copper-Catalyzed Carbonylative Cross-Coupling of Alkyl Iodides and Amines

A general copper-catalyzed carbonylative cross-coupling between amines and alkyl iodides is reported. Using a simple combination of catalytic amounts of copper(I) chloride and N,N,N’,N”,N”-pentamethyldiethylenetriamine in the presence of sodium hydroxide under carbon monoxide pressure, a broad range of alkyl iodides and amines can be efficiently coupled to the corresponding amides that are obtained in good to excellent yields. Notable features of this process – the first one relying on a base metal catalyst – include the availability and low cost of the catalytic system, its successful use with primary, secondary, tertiary alkyl iodides and all classes of amines – with no or limited competing nucleophilic substitution without CO incorporation – as well as its efficiency with complex alkyl iodides and amines. Mechanistic studies demonstrated that a radical pathway is operative and the key role of CO.     

A Facile Conversion of Halides. Alcohols and Olefins to Esters Usihg Iron(III) Perchlorate

A facile method has been developed for the ester ification of halides/alcohols/olefins with carboxylic acids using iron(III) perchlorate.     

从叔醇制备叔硫醇

实验室中合成叔硫醇缺少简便方法。用叔醇和氢溴酸与硫脲直接反应是目前采用的方法。Lee和Akerstrom曾用此法合成了叔硫醇,但碳原子数没超过七个。Sprague及Kresze分别用干燥氯化氢及盐酸代替氢溴酸也合成了叔硫醇,但产率不高。本文提出了用叔醇、硫酸与硫脲反应来制备叔硫醇的方法,并合成了六个叔硫醇。     

Selective Oxidation of Secondary Alcohols in the Presence of Primary Alcohols by an Oxoammonium Salt

Recent reports on the oxidation of alcohols by piperidine oxoammonium salts(1) have aroused much interest in investigation.Semmelhack has found that alcohols can be electrooxidized to aldehydes or ketones at a low potential when the reaction is mediated with 2,2,6,6-tetramethylpiperidinyl-l-oxy radical (2a) and proposed that the oxoammonium ion (la) is the active oxidizing     

Cu‐Catalyzed Hydroxymethylation of Unactivated Alkyl Iodides with CO To Provide One‐Carbon‐Extended Alcohols

We have developed a reductive carbonylation method by which unactivated alkyl iodides can be hydroxymethylated to provide one‐carbon‐extended alcohol products under Cu‐catalyzed conditions. The method is tolerant of alkyl β‐hydrogen atoms, is robust towards a wide variety of functional groups, and was applied to primary, secondary, and tertiary alkyl iodide substrates. Mechanistic experiments indicate that the transformation proceeds by atom‐transfer carbonylation (ATC) of the alkyl iodide followed in tandem by two CuH‐mediated reductions in rapid succession. This radical mechanism renders the Cu‐catalyzed system complementary to precious‐metal‐catalyzed reductive carbonylation reactions.     

Copper‐Catalyzed Amidation of Primary and Secondary Alkyl Boronic Esters

The oxidative copper‐catalyzed cross‐coupling of functionalized alkyl boronic esters with primary amides is reported. Through the identification of appropriate diketimine ligands, conditions for efficient coupling of both primary and secondary alkyl boronic esters with diverse primary amides, including acetamide, have been developed.     

Phase Transfer Catalysis without Solvent. Use of Alkyl Iodides

The Phase Transfer Catalysis (PTC) without solvent method allows the use of quaternary ammonium salts (QAS) when alkyl iodides are used.     

碘代烷烃在532 nm激光作用下多光子电离解离机理

利用５３２ｎｍ的激光对碘代烷烃（碘甲烷、碘乙烷、碘代正丙异丙烷）分子作了多光了电离解离（ＭＰＩＤ）质谱（ＭＳ）研究,在５３２ｎｍ激光作用下,ＣＨ３Ｉ分子吸收５３２ｎｍ激光双光子的能量,进入Ａ带的ＩＡ２态,继续吸收光子上泵浦至电离态形成母体离子ＣＨ３Ｉ,然后再形成碎片离子;而其它几个碘代烷烃吸收双光子的能量进入Ａ带后均形成中性碎片,中性碎片再吸收光子经一系列电离解离形成碎片离子,此外,本文还通过对同     

Facile One-pot Transformation of 2,3-Epoxy Alcohols into Allylic Alcohols

Optically-active allylic alcohols have been frequently used as chiral building blocks for the preparation of optically pure compounds.¹ There are at present various methods for the synthesis of optically active allylic alcohols including the kinetic resolution racemic allylic alcohols,² reductive rearrangement of 2,3-epoxy alcohol by metal, halide and telluium-based chemistry.³ To our knowledge, One-pot Transformation of 2,3-epoxy alcohols into allylic alcohols, especially via epoxy iodides,is limited to Dorta's method³ using a Ph₃P,iodine, imidazole,2,6-lutidine and water system. The original Dorta's method can be successfully applied to the formation of tertiary allylic alcohols, but give unsatisfactory results in formation of secondary allylic alcohols.