基于末端炔烃一锅法合成取代噻吩和呋喃化合物

噻吩和呋喃衍生物是许多天然产物、药物和发光材料的核心骨架,因此发展一种从简单易得的原料高效合成呋喃和噻吩衍生物的方法具有非常重要的应用价值.该研究实现了一锅法高产率合成2,5-二取代呋喃、2,5-二取代噻吩、苯并呋喃和苯并噻吩化合物.首先通过铜催化末端炔烃Glaser偶联反应合成1,4-二取代丁二炔化合物,接着硫化钠(氢氧化钾)参与水解和环化反应得到2,5-二取代噻吩和呋喃化合物.该合成策略同样适用于合成苯并呋喃和苯并噻吩化合物,通过末端炔与邻氟碘苯的Sonogashira偶联反应,然后硫化钠(或氢氧化钾)参与碳氟键的水解和环化反应得到相应的苯并噻吩和苯并呋喃化合物.该合成方法具有反应条件温和、操作简便和高产率等优点,可为该类呋喃和噻吩的合成提供简便的途径.     

苯炔与硝酮[3+2]环加成制备二取代苯并异噁唑烷

采用[3 2]1,3-偶极环加成反应,苯炔前体邻-三甲硅基苯酚三氟甲磺酸酯在氟化铯的作用下与硝酮反应合成了9个2,3-二取代苯并[d]异噁唑烷,收率87%～97%。其结构经1H NMR,13C NMR和高分辨率MS确证。     

2-(2,6-二烷氧基苯基)苯并呋喃衍生物的合成

以焦性没食子酸、4-羟基苯甲醛和酚为原料, 以邻碘代苯酚与苯乙炔衍生物的Sonogashira偶联及其连串化反应生成苯并呋喃环为关键步骤, 设计合成了一系列2-(2 ,6 -二烷氧基苯基)苯并呋喃衍生物, 并对产物进行了¹H NMR, ¹³C NMR, MS等表征.     

苯炔前体邻-三甲硅基苯酚三氟甲磺酸酯的合成

以邻溴苯酚为起始原料,经硅基化、水解和酯化反应得到苯炔前体邻-三甲硅基苯酚三氟甲磺酸酯,总收率75%。其结构经1HNMR,13CNMR,19FNMR和IR表征。     

亲电环化合成异喹啉的研究进展

综述了以2-炔基苄亚胺、2-炔基苄基叠氮、2-炔基苯甲醛肟及其2-炔基苯甲醛腙为底物,在亲电试剂催化下合成多取代异喹啉及其衍生物,对部分反应的机理进行了讨论,并对比讨论了这四种底物合成方法的优缺点.2-炔基苯甲醛肟及2-炔基苯甲醛腙的衍生物与亲电试剂反应不仅可以生成异喹啉骨架的叶立德化合物,而且这些叶立德可以一步与活性...     

亲电环化合成异喹啉的研究进展

综述了以2-炔基苄亚胺、2-炔基苄基叠氮、2-炔基苯甲醛肟及其2-炔基苯甲醛腙为底物,在亲电试剂催化下合成多取代异喹啉及其衍生物,对部分反应的机理进行了讨论,并对比讨论了这四种底物合成方法的优缺点.2-炔基苯甲醛肟及2-炔基苯甲醛腙的衍生物与亲电试剂反应不仅可以生成异喹啉骨架的叶立德化合物,而且这些叶立德可以一步与活性...     

苯并呋喃-3-甲酸乙酯的合成方法改进

苯并呋喃骨架广泛存在于天然产物与合成药物中,许多苯并呋喃类衍生物具有重要的生理、药理和毒理学活性,其合成方法备受人们的关注。本文通过"一锅法"合成苯并呋喃-3-甲酸乙酯,在Et_3N存在下以甲苯作溶剂、邻碘苯酚与丙炔酸乙酯的投料摩尔比1∶1. 5,室温反应20min后加入K_2CO_3和Pd(OAc)2/PPh3,85℃反应3. 5h,产率达到78%。本方法避免了反应过程中使用毒性较大的重氮类化合物,反应步骤少,时间短,操作简便,产率较高,并且可以较方便地对目标分子进行结构改变和修饰,对类似化合物的合成具有指导作用。     

3-亚甲基异苯并呋喃-1(3H)-酮的合成新方法

本文报道了3-亚甲基异苯并呋喃-1(3H)-酮的高效合成方法。其特点是以邻甲基苯甲酸为原料,采用"一锅法"经过酯化,自由基溴代,形成季鏻盐三步反应得到2-[(溴三苯基正膦基)甲基]苯甲酸甲酯;随后经过改进的Wittig反应,酯水解合成了邻乙烯基苯甲酸;再与KI/I2溶液发生环合反应生成3-碘甲基异苯并呋喃-1(3H)-酮;最后发生消除反应得到所需要的产物。该方法具有原料易得、价格低廉、反应条件温和、收率高等优点。化合物结构用1H NMR、13C NMR和IR表征。     

哌啶乙酸盐催化合成2,3-二取代-苯并二氢吡喃-4-酮和2,2-二取代-苯并呋喃-3-酮类衍生物

发展了一种以哌啶乙酸盐为催化剂,催化邻羟基苯基β-二酮和不同系列醛进行Knoevenagel与O-Micheal串联反应的新方法,以较好的底物适应性及中等以上的产率,合成了16个2,3-二取代苯并二氢吡喃-4-酮和9个2,2-二取代苯并呋喃-3-酮类衍生物,并且该串联反应合成途径简捷,反应条件温和,催化剂廉价易得.     

锡粉促进下1,3-二取代-1,3-二氢异苯并呋喃化合物的合成（英文）

探究了锡粉促进下邻甲酰基查尔酮与烯丙基溴的串联烯丙基化/oxa-Michael加成反应,为合成具有潜在生物活性的1,3-二取代-1,3-二氢异苯并呋喃提供了简便的方法.该方法具有反应时间短,操作简单,产率优良等优点,并进一步拓宽了锡粉促进下的反应类型．     

Reactions of o‐quinones with α‐methyl‐ (or methylene) substituted phosphorus ylides. Synthesis of benzo[b]furan derivatives

In Wittig reaction of some α‐methyl‐ and α‐methylene‐substituted phosphorus ylides with o‐quinones, benzo[b]furan derivatives were obtained via the cyclization of the o‐vinylphenols, initially formed from the tautomerization of the corresponding intermediate o‐quinone methides.     

A new approach for the synthesis of some pyrazolo[5,1‐c]triazines and pyrazolo[1,5‐a]pyrimidines containing naphtofuran moiety

Naphtho[2,1‐b]furan‐2‐yl)(8‐phenylpyrazolo[5,1‐c][1,2,4]triazin‐3‐yl)methanone, ([1,2,4]triazolo[3,4‐c][1,2,4]triazin‐6‐yl)(naphtho[2,1‐b]furan‐2‐yl)methanone, benzo[4,5]imidazo[2,1‐c][1,2,4]triazin‐3‐yl‐naphtho[2,1‐b]furan‐2‐yl‐methanone, 5‐(naphtho[2,1‐b]furan‐2‐yl)pyrazolo[1,5‐a]pyrimidine, 7‐(naphtho[2,1‐b]furan‐2‐yl)‐[1,2,4]triazolo[4,3‐a]pyrimidine, 2‐naphtho[2,1‐b]furan‐2‐yl‐benzo[4,5]imidazo[1,2‐a]pyrimidine, pyridine, and pyrazole derivatives are synthesized from sodium salt of 5‐hydroxy‐1‐naphtho[2,1‐b]furan‐2‐ylpropenone and various reagents. The newly synthesized compounds were elucidated by elemental analysis, spectral data, chemical transformation, and alternative synthetic route whenever possible. J. Heterocyclic Chem., (2012).     

Synthesis and Characterization of Biphenylene‐Containing Diazaacenes

We describe the efficient synthesis of substituted benzo[3,4]cyclobuta[1,2‐b]phenazine, benzo[3,4]cyclobuta[1,2]benzo[1,2‐i]phenazine, and benzo[3,4]cyclobuta[1,2‐b]naphtho[2,3‐i]phenazine by a condensation reaction of aromatic diamines with the stable biphenylene‐2,3‐dione.     

Reaction of 2‐acyl‐6‐methylbenzo[b]furan‐3‐acetic acids derivatives with hydrazine

Reaction of 2‐acyl‐6‐methylbenzo[b]furan‐3‐acetic acids and their derivatives such as amides and esters with hydrazine does not give expected 1‐alkyl‐5H‐benzofuro[2,3‐e]diazepin‐4‐ones ones but results in 2‐amino‐7‐methyl‐2H‐benzo[4,5]furo[2,3‐c]pyridin‐3‐ones or (3‐R‐6‐methylbenzo[b]furan‐2‐yl)alkyl ketone azines.     

Efficient Synthetic Approach to Substituted Benzo[b]furans and Benzo[b]thiophenes by Iodine‐Promoted Cyclization of Enaminones

An efficient synthetic approach to the substituted benzo[b]furan and benzo[b]thiophene scaffolds by iodine‐mediated cyclization of the corresponding enaminones is described. This protocol was applied to a large series of these latter precursors to afford the respective benzoheterocycles substituted at the C‐2 position by a carbonyl group functionality. A study of the factors that control this process reveals that the reactivity depends on the presence of electron‐donor groups in the aryl ring of the aryloxycarbonylic and arylthiocarbonylic moieties.     

New Synthetic Approach to Naphtho[1,2‐b]furan and 4′‐Oxo‐Substituted Spiro[cyclopropane‐1,1′(4′H)‐naphthalene] Derivatives

A one‐step synthesis of ethyl 2,3‐dihydronaphtho[1,2‐b]furan‐2‐carboxylate and/or ethyl 4′‐oxospiro[cyclopropane‐1,1′(4′H)‐naphthalene]‐2′‐carboxylate derivatives 2 and 3 , respectively, from substituted naphthalen‐1‐ols and ethyl 2,3‐dibromopropanoate is described (Scheme 1). Compounds 2 were easily aromatized (Scheme 2). In the same way, 3,4‐dibromobutan‐2‐one afforded the corresponding 1‐(2,3‐dihydronaphtho[1,2‐b]furan‐2‐yl)ethanone and/or spiro derivatives 8 and 9 , respectively (Scheme 6). A mechanism for the formation of the dihydronaphtho[1,2‐b]furan ring and of the spiro compounds 3 is proposed (Schemes 3 and 4). The structures of spiro compounds 3a and 3f were established by X‐ray structural analysis. The reactivity of compound 3a was also briefly examined (Scheme 9).     

Preparation of 3‐aminoalkylbenzo[b]thiophenes

We report an efficient entry into substituted 3‐(ω‐aminoalkyl)‐benzo[b]thiophenes that allows rapid generation of structural diversity. Alkylation of α,ω‐dihaloketones with thiophenols followed by acid‐catalysed cyclisation led to an efficient synthesis of 3‐(ω‐aminoalkyl)benzo[b]thiophenes. 2‐Carboethoxy derivatives were prepared using a directed ortho‐metallation approach. These derivatives were readily converted into the corresponding amines.     

Synthesis of pyrazolo[1,5‐a]‐, 1,2,4‐triazolo[1,5‐a]‐ and imidazo[1,2‐a]pyrimidines related to zaleplon,a new drug for the treatment of insomnia

This paper describes the preparation of some pyrazolo[1,5‐a]‐, 1,2,4‐triazolo[1,5‐a]‐ and imidazo[1,2‐a]‐pyrimidines substituted on the pyrimidine moiety by a 4‐[(N‐acetyl‐N‐ethyl)amino]phenyl group. A new synthesis of related benzo[h]pyrazolo[1,5‐a]‐, benzo[h]pyrazolo[5,1‐b]‐ and benzo[h]1,2,4‐triazolo[1,5‐a]‐quinazolines is also reported.     

First Synthesis of Highly Chemiluminescent Benzo[b]furan‐2(3H)‐ones Bearing a Urea Substructure

A series of benzo[b]furan‐2(3H)‐ones (coumaran‐2‐ones) bearing a urea substructure, namely derivatives of 3‐(aminocarbonylamino)benzo[b]furan‐2(3H)‐one, was prepared for the first time. The accessibility of these compounds through an electrophilic α‐amidoalkylation approach of phenols (Tscherniac–Einhorn reaction) in the key step as well as the chemiluminescence (CL) properties of the desired compounds are strongly dependent on the substitution patterns at the urea moiety. Competing reaction pathways are discussed and an improved one pot synthetical approach of also general interest is presented. In conclusion, especially N,N‐dialkylaminocarbonylamino‐derivatives of benzo[b]furan‐2(3H)‐ones exhibit a strong flash like blue CL upon treatment with bases such as 1,8‐diazabicyclo[5.4.0]undec‐7‐ene (DBU) in the presence of oxygen or hydrogen peroxide. Comparative physico‐chemical investigations revealed that novel compounds outperform their urethane‐analogues in terms of CL‐intensity and the speed of the decay making them potentially useful as new tools for CL‐based applications on the short time scale.     

Synthesis of Imidazo[1,2‐a]pyridines and Imidazo[2,1‐b]thiazoles Attached to a Cycloalkyl or Saturated Heterocycle Containing a Tertiary Hydroxy Substitution

A new method has been developed for the synthesis of imidazo[1,2‐a]pyridines, imidazo[2,1‐b]thiazoles, and benzo[d]imidazo[2,1‐b]thiazoles attached to a cycloalkyl or saturated heterocycle containing a tertiary hydroxy substitution. Readily available substituted 2‐aminopyridines, 2‐aminothiazoles, and 2‐aminobenzothiazoles were treated with bromohydroxycycloalkyl ethanones to afford the desired products in good yields.