氮杂环卡宾催化合成氰基化合物的研究进展

氰基化合物不仅广泛存在于医药和农药分子中,还是一类重要的中间体.传统合成氰基化合物的方法是使用氰化钠、氰化钾和氢氰酸等最简单的氰化试剂,但这类氰化试剂的剧毒性和不稳定性限制了其在合成中的应用.因此发展有机氰化试剂和无氰源试剂构建氰基化合物的策略备受关注.氮杂环卡宾是一类高效的有机小分子催化剂,可用于实现多种碳-碳(C—C)和碳-杂(C—X)键的形成.综述了氮杂环卡宾催化有机氰化试剂和无氰源试剂构建氰基化合物的反应,目的是引起更多的化学工作者关注该领域的发展,并提供氮杂环卡宾催化活化模式的新思路.     

5-(1-芳基-1-吡咯-2-基)-1氢-四唑类化合物的合成与表征

利用阳极氧化反应, 将一系列N-芳基吡咯电氰化, 区域专一地得到吡咯氰化物2, 分离收率为76%~85%. 将其与叠氮化钠反应, 合成了一系列具有潜在血管紧张素Ⅱ受体(AT)拮抗活性的新型四唑化合物. 该合成路线的原料易得, 并以阳极氰化芳香氮杂环引入氰基为关键步骤, 可作为在芳香氮杂环上引入四唑基团的通用合成路线.     

以四硫代钒酸盐为合成子的反应体系

四硫代钒酸盐被认为是一类良好的反应前体,利用它们可以方便地得到结构新颖、性质丰富的同(异)核金属硫簇化合物,在无机合成中具有重要的应用价值.本文系统介绍并评述了四硫代钒酸盐作为反应原料在不同反应体系中的反应性能和反应规律以及在合成同核、异核钒化合物中的应用.     

环钯化合物在Heck反应中的应用研究

钯催化交叉偶联反应在化学工业、合成天然产物及生物活性物质中有着广泛的应用.催化剂体系是交叉偶联反应研究的核心.环钯化合物结构简单、性能稳定,在催化交叉偶联反应中具有高活性、高选择性,引起研究者们的极大关注,不断有新的环钯化合物被合成出来,其催化性能也得到了研究.本文综述了环钯化合物的合成方法及其在Heck反应中的应用.     

环链转移反应及其在合成杂环化合物中的应用

概括了环链转移反应的类型、机理,同时综述了环链转移反应在合成取代杂环化合物中的应用。     

植物细胞在含羰基化合物不对称转化中的应用

本文综述了用植物细胞催化含羰基化合物的不对称转化的最新进展,并对底物结构和植物催化类型等影响反应结果的因素进行了讨论,指出了植物细胞作为生物催化剂需解决的问题.植物细胞不仅可以对映选择性地还原一些酮类和α-酮酸酯或β-酮酸酯类化合物中的羰基,而且可以催化醛类化合物的羰基进行不对称羟氰化反应,还可以区域选择性地转化一些不饱和羰基化合物中的碳碳双键等.不同植物的细胞或同一种植物的不同细胞对底物的转化均具有不同的区域和立体选择性.底物中取代基的空间效应和电子效应也影响不对称转化的结果,但空间效应的影响更加显著.     

稀土铅钙合金与传统铅钙合金在硫酸溶液中的阳极行为研究

应用交流阻抗,交流伏安和循环伏安等方法研究了Pb-Ca-Sn-Re合金和Pb-Ca-Sn合金在1.28 V(vs.SCE)和4.5 mol/L硫酸溶液中的阳极行为.结果表明:稀土铅钙合金提高了合金的耐腐蚀性能,同时抑制其阳极膜中Pb(Ⅱ)化合物的生长,从而降低阳极膜的阻抗,提高膜的导电性能,这对改善电池的深循环性能十分有利.     

多组分反应合成杂环化合物研究进展

利用多组分反应合成结构复杂多样的杂环化合物,在有机合成领域具有广阔的应用前景和研究价值.本文综述了近年来多组分反应在五元杂环、六元杂环、多元杂环合成中的研究进展,同时对杂环化合物的绿色合成方法做出展望.     

三甲基硅化腈在有机合成中的应用

三甲基硅化腈是一种常用的有机合成试剂. 对近年来三甲基硅化腈在有机合成中的应用进行了简要的总结和概述, 重点介绍了三甲基硅化腈作为强的亲核试剂广泛用于环氮和环氧化合物的开环反应、亚胺和醛酮类化合物的加成、胺与醛或酮参与的多组分反应、偶联反应以及对炔和具有较高活性的碳碳双键的氰化加成等反应.     

有机锑化合物在交叉偶联反应中的应用研究进展

近年来,有机锑化合物在交叉偶联反应中的应用引起了人们的广泛关注。本文主要对有机锑化合物在交叉偶联反应中的应用作了综述,重点介绍了其在Suzuki交叉偶联反应、Heck偶联反应以及Sonogashira偶联反应中的应用,并展望了其未来的发展方向。     

Synthesis of á-aminonitrile through Anodic Cyanation of N-benzylpiperidine

Electrochemistry behaviors including linear sweep voltammetry and cyclic voltammetry of tertiary cyclic amines with different substituted group were studied. The effect of different substituted group of the nitrogen on the oxidation potential was analyzed. The most suited potential used in α-aminonitrile synthesis through potentiostatic anodic cyanation of cyclic teritary amines was found. The anodic cyanation of N-alkyl-substituted cyclic six-membered amines including N-benzylpiperidine and…     

均相salen类配合物催化不对称氰化反应研究进展

手性α-氰醇类化合物在有机合成领域中的应用非常广泛,分子中α-碳原子上连接的羟基和氰基两个官能团很容易控制、转化为大量极其重要的合成中间体,包括：α-羟基酸、α-羟基酯,α-羟基醛、α-羟基酮、α-胺基酸和β-胺基醇等.这些化合物都是工业上合成医药、农化产品、     

Anodic Cyanation of 1-（1-Methoxycarbonyl ethyl） piperidine

α-Aminonitriles were prepared efficiently from anodic cyanation of α-amino ester. The effect of different solvents and electrolytes was studied. The other byproducts were analyzed.     

DMAP-catalyzed cyanation of aldehydes and ketones with ethyl cyanoformate

The cyanation of carbonyl compounds with ethyl cyanoformate is catalyzed by 4-dimethylaminopyridine (DMAP) to afford the corresponding cyanohydrin carbonates in excellent yields. The system provides a convenient method for cyanation of carbonyl compounds without using metal catalysts or solvents.     

N-heterocyclic carbene catalyzed cyanation reaction of carbonyl compounds with ethyl cyanoformate and acetyl cyanide

N-heterocyclic carbene (NHC) has been employed as an efficient catalyst for cyanation reaction of carbonyl compounds. Under catalysis of 1 mol % NHCs, various aldehydes and 2,2,2-trifluoroacetophenone coupled with ethyl cyanoformate in THF to provide cyanohydrins ethyl carbonates in excellent yields. While in the presence of 10 mol % catalyst, different types of aldehydes and 2,2,2-trifluoroacetophenone reacted with acetyl cyanide in dichloroethane to give acylated cyanohydrins in moderate to high yields.     

Synthesis α‐aminonitrile through anodic cyanation of N‐benzylpiperidine

Six‐membered cyclic α‐aminonitrile has been prepared from anodic cyanation of N‐benzylpiperidine. Good yields of α‐aminonitriles could be obtained through potentiostatic electrolysis under different conditions. The results also explain why high yield α‐aminonitriles could not be obtained under constant current electrolysis.     

Recent advances on boron doped diamond (BDD) electrode as cathode in organic and inorganic preparative electrotransformations

Although anodic oxidation reactions mediated by boron-doped diamond (BDD) electrodes have been broadly studied, research on cathodic conversion remains still scarce despite the favorable characteristics of this electrode for such application. A detailed survey of the recent literature about processes in which boron-doped diamond electrode has been employed in cathodic reactions is presented, including inorganic species (O₂, CO₂, nitrate, metaborate) and organic compounds (carbonyl, nitro groups and halogenated compounds).     

钒(V)化合物在硫酸中的电化学行为研究

应用循环伏安法和旋转环盘电极法研究了H2 SO4 溶液中五价钒化合物 (NH4 VO3和V2 O5)的电化学行为 .由光滑Pt电极测得其CV图 ,两者的基本峰位和峰形都很相似 ,通常出现三个还原峰和三个氧化峰 ,但NH4 VO3多一个氧化峰 ,RRDE测定也出现了四个氧化峰 ,本文分析了这些对应峰的反应 ,并给予初步解释     

Cyanide-Free Cyanation of sp2 and sp-Carbon Atoms by an Oxazole-Based Masked CN Source Using Flow Microreactors

This work reports a cyanide-free continuous-flow process for cyanation of sp² and sp carbons to synthesize aryl, vinyl and acetylenic nitriles from (5-methyl-2-phenyloxazol-4-yl) boronic acid [OxBA] reagent as a sole source of carbon-bound masked −CN source. Non-toxic and stable OxBA reagent is generated by lithiation-borylation of bromo-oxazole, and the consecutive Suzuki-Miyaura cross-coupling with aryl, vinyl, or acetylenic halides and demasking [4+2]/retro-[4+2] sequence were successfully accomplished to give the desired cyano compounds with reasonably good yields in a four-step flow manner. A unique feature of this cyanation protocol in flow enables to cyanate a variety of sp² and sp carbons to produce a broad spectrum of aryl acetonitrile. It is envisaged that the OxBA based cyanation would replace existing unstable and toxic approaches as well as non-toxic cyanation using two different sources of “C” and “N” to incorporate the −CN group.     

Mild and efficient copper-catalyzed cyanation of aryl iodides and bromides

An efficient copper-catalyzed cyanation of aryl iodides and bromides is reported. Our system combines catalytic amounts of both copper salts and chelating ligands. The latter, which have potential nitrogen- and/or oxygen-binding sites, have never previously been used in this type of reaction. A protocol has been developed that enables the cyanation of aryl bromides through the copper-catalyzed in situ production of the corresponding aryl iodides using catalytic amounts of potassium iodide. Aryl nitriles are obtained in good yields and excellent selectivities in relatively mild conditions (110 degrees C) compared with the Rosenmund-von Braun cyanation reaction. Furthermore, the reaction is compatible with a wide range of functional groups including nitro and amino substituents. The protocol reported herein involves two main innovations: the use of catalytic amounts of ligands and the use of acetone cyanohydrin as the cyanating agent in copper-mediated cyanation reactions.