醋酸锌催化串联反应合成2-氨基-3-氰基-4H-吡喃类衍生物

以氰基查尔酮类化合物及丙二腈为原料,醋酸锌为催化剂,经串联反应合成2-氨基-4H-吡喃类衍生物。考察催化剂、溶剂、反应时间及温度、原料摩尔比对产率的影响。最优条件为：氰基查尔酮类化合物与丙二腈物质的量比为1.0:1.0,醋酸锌(10mol%)作催化剂,二氯甲烷作溶剂,反应温度为30℃,产率最高为99.5%。     

三组分反应合成多官能团化α-氰基噻吩的简便方法

本文报道了一种利用多组分反应合成α-氰基噻吩的新方法. 在碱存在条件下, β-二羰基化合物、二硫化碳和溴乙腈经过连续的多步反应, “一锅”合成多官能团化的α-氰基噻吩. 该方法简洁, 条件温和, 产率高.     

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.     

醋酸锌催化串联反应合成2-氨基-3-氰基-4H-吡喃衍生物

以氰基查尔酮类化合物及丙二腈为原料,醋酸锌为催化剂,经串联反应合成了一系列2-氨基-4H-吡喃类衍生物。考察了催化剂、溶剂、反应时间及温度、原料摩尔比对产率的影响。确定的优化反应条件为:氰基查尔酮类化合物与丙二腈摩尔比为1∶1,醋酸锌(10(mol)%))作催化剂,二氯甲烷作溶剂,反应温度为30℃。此条件下,最高产率可达99.5%。     

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。     

氰基取代的含杂环烯酮缩胺的合成及其波谱和结构特性

由氰基乙酸酯或丙二腈先制得氰基取代的烯酮缩硫醇, 然后与二胺反应合成了氰基取代的含杂环烯酮缩胺, 测定了它们的UV、IR、^1H及^1^3C NMR等波谱, 并测定了其中两个化合物的晶体结构, 对所得的波谱和结构特性进行了讨论。     

方便、有效的方法合成2-氨基-1,3-二氰基-4-芳基-5,6,7,8,9,10,11,12,13,14-十氢苯并[12]轮烯衍生物

芳香醛、环十二酮和丙二腈在苄胺存在下于95%乙醇中反应,方便地合成了一系列2-氨基-1,3-二氰基-4-芳基-5,6,7,8,9,10,11,12,13,14-十氢苯并[12]轮烯衍生物,苄胺作为碱催化此类的反应还未见报道.产物的结构经过红外、核磁和高分辨质谱确定.本方法具有反应时间短、容易操作、产率高等优点,是合成此类化合物的一条有效途径.     

无催化剂、三组分一锅法合成2-氨基-3-氰基-4H-吡喃类化合物

4-H-吡喃类化合物在医药、化工、有机合成等方面应用广泛,因此,发展其有效的合成方法具有重要意义。本文主要研究无催化剂条件下,以水作为反应介质,乙醇作为辅助溶剂,促进芳香醛、丙二腈与多种1,3-二羰基化合物的三组分"一锅法"缩合反应,高产率地合成了3种超过50个2-氨基-3-氰基-4H-吡喃类化合物并进行了系统的结构表征。该方法具有反应条件温和、不使用催化剂、底物适用性广、反应和后处理过程简单以及环境友好等优点。     

2-氨基-3-氰基-4-芳基-6-二茂铁基吡啶的合成

以乙酰二茂铁、芳香醛、丙二腈为原料, 在乙酸铵存在下以乙醇为溶剂, 采用一锅煮的方法合成了8个2-氨基-3-氰基-4-芳基-6-二茂铁基吡啶化合物, 产率中等. 并通过X射线衍射分析确证产物4e的结构.     

丙二腈类衍生物应用及合成研究进展

丙二腈类衍生物在农药方面良好的除草、杀菌、杀虫等生物活性得到了深入研究,在医药、染料等方面的用途也有报道;丙二腈双氰基强吸电子性的特点,导致亚甲基上两个氢都很活泼,容易发生取代、加成、缩合、消去等反应。依据丙二腈氰基α位取代基的结构特点将丙二腈衍生物分三类进行归纳:α位为单键的丙二腈衍生物、α位为双键的丙二腈衍生物、α位为环状结构的丙二腈衍生物,同时介绍了丙二腈类衍生物应用及合成研究进展。     

Convenient synthesis,antimicrobial evaluation and molecular modeling of some novel quinoline derivatives

α, β-Unsaturated carbonyl compounds 2a, 2b, 3, and 4 were synthesized by the Knoevenagel condensation between 2-substituted quionoline-3-carboxaldehyde 1a and/or 1b with active methylene compounds. In addition, the synthesis of azlactone is achieved starting from 1a and N-acetylglycine. Synthesis of pyridine, pyrene, and pyrimidine derivatives 6–8 were accomplished via one-pot multicomponent reaction of 1b with acetyl acetone, malononitrile, and ammonium acetate; acetophenone, malononitrile, and NaOH; or acetyl acetone and urea in acidic medium. The new synthesized compounds showed good antimicrobial activities. The DFT calculations have been used to predict the electronic properties of the studied compounds.     

碳氢化合物的活化及氧化理论研究*

通过理论方法研究碳氢化合物的活化及氧化,可以对不同催化剂及氧化剂的反应机理形成深刻认识,从而指导设计合成更加高效的碳氢化合物活化及氧化催化剂。本文总结了近几年在碳氢化合物的活化及氧化领域的一些新进展,涉及的底物包括从甲烷到碳原子数等于6的烃类,而催化剂及氧化剂包括有机金属化合物和无机化合物（如分子筛催化剂、金属团簇和金属氧化物等）。文章底物的碳原子数为依据进行分类编排,对每一类底物的活化及氧化介绍不同催化剂及氧化剂的反应过程,着重比较了各类催化剂及氧化剂的异同。     

New insight into anionic cyclizations of alkynyl- and ortho-dialkynylarenes: a specific reactivity of 3-alkynyl-2-chloro- and 2,3-dialkynylquinoxalines and related compounds toward CH-acids’ carbanions

The reactivity of 3-alkynyl-2-chloroquinoxalines, 2,3-dialkynylquinoxalines, and some related pyrazine derivatives toward carbanions of the CH-acids (malononitrile, ethyl cyanoacetate, diethyl malonate, 1,3-dimethylbarbituric acid) has been studied. Most of the observed reactions proceeded as tandem or cascade cyclizations yielding polynuclear heterocyclic compounds. The process starts with the addition of a nucleophile to an alkyne triple bond. Depending on the nature of the used C-nucleophile, the thus formed anionic adduct underwent further cyclization via (i) intramolecular nucleophilic substitution of the chlorine atom, (ii) intramolecular acylation of the ring nitrogen atom by the ester side chain or (iii) intramolecular nucleophilic attack on the second CC bond. Reactions of 3-alkynyl-2-chloro- and 2,3-dialkynylpyrazines with 1,3-dimethylbarbituric acid in the presence of t-BuOK were accompanied by recyclization of the 1,3-dimethylbarbituric acid moiety.     

Über Reaktionen einiger halogenierter Heterocyclen und N-Oxide mit reaktiven Methylenverbindungen

Reactions between some halogenated heterocycles and heterocyclic N-oxides with compounds containing reactive methylene groups are described and the structures of the products were studied.     

An efficient one-pot multicomponent approach to 5-amino-7-aryl-8-nitrothiazolo[3,2-a]pyridines

A series of thiazolo[3,2-a]pyridines have been prepared using a multicomponent reaction between aromatic aldehydes, 2-nitromethylenethiazolidine and nitriles containing an active methylene group (malononitrile, ethyl 2-cyanoacetate and 2-phenylsulfonylacetonitrile) in the presence of Et₃N under mild conditions with high yields. One of the compounds shows promising anticancer activity across a range of cancer cell lines.     

Electrocatalytic Fast and Efficient Multicomponent Approach to Medicinally Relevant (2‐Amino‐4H‐chromen‐4‐yl) phosphonate Scaffold

‘One‐pot’ electrocatalytic transformation of salicylaldehydes, malononitrile, and triethyl phosphite in an undivided cell results in the formation of diethyl (2‐amino‐3‐cyano‐4H‐chromen‐4‐yl)phosphonates in 88–93% substance yields and 880–930% current efficiency via complex multicomponent process. This novel electrocatalytic chain process opens an effective, fast, and convenient way to cyano‐functionalized (2‐amino‐4H‐chromen‐4‐yl)phosphonate systems which are promising compounds for biomedical applications. This efficient electrocatalytic approach to the (2‐amino‐4H‐chromen‐4‐yl)phosphonate scaffold represents novel synthetic concept for multicomponent reactions (MCR) strategy and allows to combine the synthetic virtues of conventional MCR with ecological benefits and convenience of facile electrocatalytic procedure.     

Chemical behavior of 4,9-dimethoxy-5-oxo-5H-furo[3,2-g]chromene-6-carboxaldehyde towards carbon nucleophilic reagents

The chemical behavior of 6-formylkhellin ( 1 ) was investigated toward a variety of carbon nucleophiles. Treatment of aldehyde 1 with cyanoacetamide, N-benzylcyanoacetamide produced pyridine-3-carboxamides 3 and 4 . Treatment of carboxaldehyde 1 with malononitrile dimer and 1H-benzimidazol-2-ylacetonitrile gave 1,6-naphthyridine 5 and pyrido[1,2-a]benzimidazole 6 , respectively. Some novel pyrazolo[3,4-b]pyridine 7 , pyrido[2,3-d]pyrimidines 8 and 9 were synthesized from the ring opening ring closure reactions of carboxaldehyde 1 with certain heterocyclic enamines. In addition, reaction of carboxaldehyde 1 with certain cyclic enols produced a variety of products. Treatment of carboxaldehyde 1 with 1,3-cyclohexanediones gave xanthene-1,8-diones 19 and 20 . Reaction of carboxaldehyde 1 with 5-methyl-2,4-dihydro-3H-pyrazol-3-one proceeds in 1:2 M ratio producing pyrazolo [4′,3′:5,6]pyrano[2,3-c]pyrazole derivative 22 . Carboxaldehyde 1 reacted with certain heterocyclic compounds containing active methylene groups to give the corresponding condensation products 22 - 27 . The synthesized compounds were screened in vitro for their antimicrobial activity and showed high to moderate activities against the tested microorganisms.     

Design,Synthesis, and Antimicrobial Evaluation of some Novel Pyridine,Coumarin, and Thiazole Derivatives

Treatment of 2‐cyano‐N′‐(1‐(pyridin‐2‐yl)ethylidene)acetohydrazide 1 with aromatic/heterocyclic aldehydes 2a–f gave arylidene derivatives 3a–f . Polysubstituted pyridine derivatives 4a,b were prepared either from reaction of arylidene 3a,b with malononitrile or from reaction of acetohydrazide 1 with arylidenemalononitrile 5a,b . Cyclocondensation of acetohydrazide 1 with salicylaldehyde derivatives and acetylacetone furnished pyrido‐coumarins 6,7 and 2‐pyridone‐3‐carbonitrile 8, respectively. In addition, pyrido‐thiazoles 13 and 15 were obtained through reaction of 2‐(1‐(pyridin‐2‐yl)ethylidene)hydrazinecarbothioamide 11 with hydrazonyl chlorides and α‐haloketones, respectively. The structures of synthesized compounds were elucidated with spectral and elemental data. The antimicrobial activity of the synthesized compounds was studied.     

Synthesis and [3+2] cycloaddition reaction of 3‐[(trimethylsilylmethylamino)(methylthio)‐methylene]heterocyclic compounds

3‐[(Trimethylsilylmethylamino)(methylthio)]methylene‐2‐coumaranone ( 4a ) and 1‐methyloxindole ( 4b ), readily prepared by reactions of the corresponding bis(methylthio)methylene heterocyclic compounds ( 2a, b ), with (trimethylsilylmethyl)amine (3), were found to be synthetic equivalents of heterocyclic alkylidene‐azomethine ylides. Reactions of 4a, b with reactive heterodipolarophiles such as aldehydes and ketones and reactive alkenes in the presence of cesium fluoride gave the 1,3‐dipolar cycloadducts, 3‐(2‐oxazoli‐dinylidene)‐oxindole and ‐coumaran‐2‐one derivatives ( 8a‐j, 9a‐h ), as well as pyrrolylidenecoumaran‐2‐one and oxindole derivatives ( 12‐15,17,18 ), via the 1,3‐elimination of (methylthio)trimethylsilane.     

Improved Protocol for Thorpe Reaction: Synthesis of 4‐Amino‐1‐arylpyrazole using Solid–Liquid Phase‐Transfer Conditions

Solid–liquid phase‐transfer conditions were employed for the first time in the Thorpe reaction to synthesize 4‐amino‐1‐aryl‐3,5‐substituted‐1H‐pyrazoles 3. Aryl amines were diazotized and coupled with various active methylene compounds such as cyano acetamide, cyanoacetophenone, malononitrile, and ethyl cyanoacetate, resulting into α‐arylhydrazononitriles 1. Cyclization of 1 using α‐bromo ketones or esters resulted in compounds 3.