合成芳基1-三氟甲基-2-氧杂-全氟戊基酮的新法

本文报道了合成芳基1-三氟甲基-2-氧杂-全氟戊基酮的一个简便方法,即在极性非质子溶剂中,用金属卤化物分解2-三氟甲基-3-氧杂-八氟己酸甲酯(1),由此所产生的R_F~-[R_F=n-C_3F_7OCF(CF_3)]与加入体系中的取代苯甲酰氯(YArCOCl)反应,即可得到目标产物R_FCOArY(2a～21).对反应机理亦作了简单的讨论.     

铜催化苯甲酰亚胺高烯丙酯的分子内胺化全氟烷基化反应

报道了铜催化苯甲酰亚胺高烯丙酯底物的分子内胺化全氟烷基化反应. 该反应以全氟碘代烷为全氟烷基化试剂, 醋酸铜为催化剂, 邻菲啰啉为配体, 在醋酸银存在下以中等的收率实现苯甲酰亚胺高烯丙酯底物末端双键的胺化全氟烷基化, 最终生成1,3-噁嗪类分子. 多种官能团取代的苯甲酰亚胺高烯丙酯和具有不同碳链长度的全氟碘代烷烃都能适用于该反应, 为多氟烷基取代的1,3-噁嗪类化合物的合成提供了一种简洁的方法. 多氟烷基取代的1,3-噁嗪类化合物还可在温和条件下高效转化为γ氨基醇衍生物. 初步的机理研究证明该反应经历了全氟烷基自由基对碳碳双键的亲电加成, 之后苯甲酰亚胺基团作为分子内亲核性胺源经历分子内亲核取代途径生成1,3-噁嗪骨架.     

全氟烷基磺酰溴与杂原子取代烯键的反应

全氟烷基磺酰溴与杂原子取代烯烃, 如溴乙烯, 乙酸乙烯酯, 三甲基硅乙烯加成, 得相应的加成物, 与烯醇硅醚反应, 水解后得到α位溴代酮和全氟烷基亚磺酸. 全氟磺酰氯与1-三甲基硅氧基-1-叔丁基乙烯在紫外光照下反应, 生成α位全氟烷基化的酮. 全氟烷基磺酰溴溴化苯酚和甲氧基苯, 得到对位溴化产物. α,α-二氯三氟乙基亚磺酸钠与溴水在20-25℃反应, 得α,α-二氯三氟乙基磺酰溴, 其化学反应性与全氟烷基磺酰溴类似, 但稳定性较差.     

钯催化的芳基C-H键三氟甲硫基化反应

报道了二价钯催化的高选择性芳基C-H键的三氟甲硫基化反应,其中稳定的三氟甲硫基苯胺2a作为三氟甲硫基试剂,醋酸钯作为催化剂,苯甲酰氯和醋酸银作为添加剂,反应在DMF中120℃条件下实现的.各种取代的吡啶都可以作为该反应的导向基团.反应中苯甲酰氯的添加对活化三氟甲硫基苯胺2a起着关键作用.该反应为合成邻位三氟甲硫基取代苯类衍生物提供了高效方便的方法.     

钯催化硼基化邻-碳硼烷偶联反应制备3,6-双芳基-邻-碳硼烷（英文）

钯催化碳硼烷基-3,6-二硼酸频哪醇酯与芳基溴化物反应,以中等的收率得到一系列硼顶点取代的3,6-双芳基-邻-碳硼烷.反应中使用(1,5-环辛二烯)二氯化钯/三环己基膦作为催化体系,可以避免钯催化芳基-芳基交换及直接硼氢键芳基化的副产物生成.反应路径包括氧化加成、离子交换、转金属以及还原消除过程.     

α-芳基-α-羟基酮(酯)与全氟烷基磺酰氟/甲基三乙氧基硅烷/碱体系不期望的氧化反应

研究了全氟烷基磺酰氟/甲基三乙氧基硅烷/碱体系与α-芳基-α-羟基酮(酯)化合物不期望的氧化反应,以中等到优良的收率生成了相应的1,2-二酮(α-酮酸酯)产物.所用全氟烷基磺酰氟为全氟正丁基磺酰氟或全氟正辛基磺酰氟;碱为1,8-二氮杂二环[5.4.0]十一碳-7-烯(DBU).提出了一种可能的反应机理.为制备芳基取代的1,2-二酮(或α-酮酸酯)化合物提供了一种新方法.     

三组分反应高效合成螺[环戊烷-1,3'-吲哚啉]衍生物（英文）

烷基异氰酸酯、丁炔二酸二酯(丙炔酸酯)和3-苯甲酰亚甲基-2-吲哚酮在甲苯中回流反应,高产率地生成螺[环戊烷-1,3'-吲哚啉]衍生物.然而,含有游离氨基的3-苯甲酰亚甲基-2-吲哚酮参加反应时,未取代的氨基可与另一分子丁炔二酸二酯及烷基异氰酸酯继续反应形成含有氨基取代的氮杂-1,3-二烯支链的螺[环戊烷-1,3'-吲哚啉]衍生物.另一方面,3-芳亚甲基吲哚-2-酮参与三组分反应时,仅有游离氨基参与反应,生成2-(2-氧吲哚-1-基)-3-[(烷基亚氨基)亚甲基]丁酸酯.发现两种游离氨基参与多组分反应时,分别形成了含有C2-取代的1-氮杂-1,3-丁二烯(C=C—C=NR)和C4-取代的1-氮杂-1,2-丁二烯(C—C=C=NR)结构单元的吲哚酮衍生物.     

取代环戊二烯基负离子的二茂铁甲酰化反应

本文以6,6-二烷基富烯与甲基锂, 芳基锂及烯丙基格式试剂反应所得的取代环戊二烯基负离子与二茂铁甲酰氯反应合成了10个新的富烯化合物, 并通过^1HNMR, IR及元素分析确定了它们的结构 .     

氟氯代β-二酮的合成

从二氟氯乙酸乙酯与甲基酮的Claisen酯缩合反应合成了一些氟氯代β-二酮.用格氏试剂与氟代羧酸酯加成,多氟芳基镉与乙酰氯反应以及氟代β-酮酸酯水解等方法合成了一些新的多氟烃基甲基酮R_FCOCH_3.     

Sc(OTf)_3催化的δ-三氟甲基-δ-芳基-双取代对亚甲基苯醌和硫醇的反应:高效合成二芳基甲烷硫醚化合物（英文）

报道了一种δ-三氟甲基-δ-芳基-二取代的对亚甲基苯醌和硫醇参与的1,6-共轭加成反应.在5mol%三氟甲基磺酸钪催化的条件下,得到了结构多样化的含有三氟甲基四级碳中心的二芳基甲烷硫醚.反应具有良好的官能团兼容性和底物范围.此外,烷基硫醇和苄硫醇也适用于该反应.鉴于二芳基甲烷硫醚骨架以及三氟甲基在生物活性分子中的重要性,发展的含有三氟甲基取代四级碳中心的二芳基甲烷硫醚的高效合成方法将为生物活性分子的发现提供一条简洁、高效的策略.     

A new method for the preparation of aryl perfluoro-1-methyl-2-oxa-pentyl ketones

The fluorocarbanion [n-C₃F₇OCF (CF₃)^?] generated by decarbomethoxylation of methyl perfluoro-2-methyl-3-oxa-hexanoate(1)can be trapped in many cases with substituted benzoyl chlorides (YArCOCl). In this way, a simple, convenient method for the preparation of aryl β-oxa-fluoroalkylketones has been developed. The mechanistic consideration of the ester decomposition induced by the lithium chloride/hexamethylphosphoric triamide complex (LiCl/HMPA) and KI/CH₃CN involves nucleophilic attack by halides on the methoxy carbon of the ester 1.     

Ligandless heterogeneous palladium: an efficient and recyclable catalyst for Suzuki‐type cross‐coupling reaction

A mild and efficient ligand‐free Suzuki‐type cross‐coupling reaction of benzoyl chlorides and arylboronic acids catalyzed by heterogeneous Pd/C was developed. Benzoyl chlorides undergo cross‐coupling with electronically diverse arylboronic acids to give biaryl ketones in excellent yield, under aqueous media and optimum temperature. The application of 3 mol% of 10 wt% Pd/C to the cross‐coupling delivers utmost efficiency, and could be reused up to many consecutive cycles without any loss in activity. This method proceeds under aqueous media and a recyclable catalytic system, offering an environmentally benign alternative to the existing protocols. Copyright © 2014 John Wiley & Sons, Ltd.     

Cyclodextrin effect on solvolysis of substituted benzoyl chlorides

A kinetic study was carried out on the solvolysis of substituted benzoyl chlorides in the presence of alpha-, beta- and gamma-CD. Combination of the substituent dependent mechanism for solvolysis of benzoyl chlorides and the complexation ability of the cyclodextrin yields the following experimental behavior: (i) catalysis by beta- and gamma-CD for solvolysis of electron-attracting substituted benzoyl chlorides due to the reaction with its hydroxyl group C(6); (ii) absence of alpha-CD influence on solvolysis of benzoyl chlorides with electron withdrawing substituents; (iii) inhibition of solvolysis of benzoyl chlorides with electron-donating groups. This behavior is observed for solvolysis of meta/para substituted substrates in the presence of beta-CD, solvolysis of meta-substituted benzoyl chlorides in the presence of alpha-CD and solvolysis of para-substituted benzoyl chlorides in the presence of gamma-CD. This decrease in the rate constant is a consequence of the complexation of the substrate in the cyclodextrin cavity and its low solvation ability, causing the rate of solvolysis in its interior to be negligible. (iv) The solvolysis of meta-substituted benzoyl chlorides in the presence of gamma-CD yields a new behavior where the reaction of the complexed substrate is not negligible in the interior of the cyclodextrin cavity, which has been interpreted as a consequence of incomplete expulsion of hydration water from its cavity when the complexation takes place. (v) The experimental results obtained in the presence of alpha-CD show that meta-substituted benzoyl chlorides give rise to host : guest complexes with 1 : 1 stoichiometries, whereas those which are para-substituted cause a 2 : 1 stoichiometry to be formed. This difference in behavior has been interpreted taking into account the size of the different benzoyl chlorides and their accommodation in the alpha-CD cavity.     

Synthesis of new 4-amino-5-(1,4-benzodioxan-2-yl)-4<Emphasis Type="Italic">H</Emphasis>-1,2,4-triazole-3-thiol derivatives

Acylation and cyclization reactions of 4-amino-5-(1,4-benzodioxan-2-yl)-4H-1,2,4-triazole-3-thiol were studied. Acylation of the title compound with substituted benzoyl chlorides gave the corresponding amides, whereas its reactions with substituted benzoic acids in the presence of POCl3 were accompanied by cyclization with formation of triazolothiadiazoles containing a 1,4-benzodioxane substituent. 4-Amino-5-(1,4-benzodioxan-2-yl)-4H-1,2,4-triazole-3-thiol reacted with substituted benzaldehydes to afford the corresponding Schiff bases, and its alkylation with chloroacetic acid in ethanol in the presence of sodium acetate gave S-ethoxycarbonylmethyl derivative.     

1,2,4-三嗪类化合物的研究XXI.3-甲硫基-5-氧代-2.5-二氧-1,2,4-三嗪的取代苯磺铣化反应及6- 碳的亲电特性

3-甲硫基-5-氧代-2.5-二氧-1,2,4-三嗪(Ic)与取代的苯磺铣氯反应,在无水吡啶中生成N-[6-(3-甲硫基-5-负氧基)-1,2,4-三嗪基]吡啶内嗡盐(4);在NaOH-H~2O-Ch~3COCH~3中生成3-甲硫基-4-(取代苯磺铣基)-5-氧化-6-羟基-1,4,5,6-四氢- 12,4-(6);资Naoh-Ch~3O中则生成1-(对甲苯磺铣基)-3-甲硫基-6-甲氧基-1,4,5,6-四氢-三嗪(7)显示了其6-C具有不寻常的亲电特性.     

The role of water release from the cyclodextrin cavity in the complexation of benzoyl chlorides by dimethyl-β-cyclodextrin

The influence of temperature on the solvolysis of substituted benzoyl chlorides in the presence of dimethyl-β-cyclodextrin (DM-β-CD) was studied. Based on the influence of the DM-β-CD concentration on chemical reactivity in this process, the cyclodextrin has a catalytic effect on the solvolysis of 4-nitrobenzoyl chloride (4-NO₂) but an inhibitory effect on that of 4-methoxy-(4-MeO), 3-chloro-(3-Cl) and 3-trifluoromethyl-(3-CF₃) benzoyl chlorides. These disparate effects are related to a difference in reaction mechanism; thus, DM-β-CD catalyses associative solvolysis and inhibits dissociative solvolysis. Examining the influence of temperature on the solvolytic process allowed the stoichiometry of the host-guest complexes formed to be established. The formation constants for the complexes of meta-substituted benzoyl chlorides increased with increasing temperature. On the other hand, the equilibrium formation constants for the 1:1 host-guest complexes of para-substituted benzoyl chlorides exhibited the opposite trend. The equilibrium formation constant for 2:1 host-guest complexes for the para-substituted benzoyl chlorides increased with increasing temperature. These differences are ascribed to the release of water from the DM-β-CD cavity during the formation of the host-guest complex.     

Synthesis of some N-[pyridyl(phenyl)carbonylamino]-alkyl-1,2,3,6-tetrahydropyridines

Alkyl substituted 2,4-dinitrophenylpyridinium chlorides 3 are formed by the nucleophilic substitution of 1-chloro-2,4-dinitrobenzene with alkyl pyridines. Reaction of pyridyl acid hydrazides or benzoyl hydrazides 4 with the pyridinium chlorides 3 furnish the isolable 2,4-dinitroanilino derivatives 5 which undergo hydrolysis when refluxed in water:p-dioxane mixture (1:4 v/v) to yield the pyridinium ylides 6 . Sodium borohydride reduction of 6 in absolute ethanol at 0° for 4 hours result the formation of the title compounds 7 in moderate to excellent yields.     

Pd(0)‐Catalyzed Tandem One‐Pot Reaction of Biphenyl Ketones/Aldehydes to the Corresponding Di‐substituted Aryl Olefins

Synthesis of di‐substituted aryl olefins via a Pd(0)‐catalyzed cross‐coupling reaction of biphenyl ketones/aldehydes, tosylhydrazide, and aryl bromides (or benzyl halides) was developed. This methodology was achieved by one‐pot two‐step reactions involving the preparation of N ‐tosylhydrazones by reacting tosylhydrazide with biphenyl ketones/aldehydes, followed by coupling with aryl bromides (or benzyl halides) in the presence of Pd(PPh₃ )₄ and lithium t ‐butoxide to produce various di‐substituted aryl olefins in moderate to good yields.     

Pd(0)/C-catalyzed cross-couplings of acyl chlorides with triarylbismuths as atom-efficient sub-stoichiometric multi-coupling reagents

Aromatic and hetero-aromatic acyl chlorides were efficiently cross-coupled with triarylbismuths as atom-efficient nucleophilic organometallic coupling reagents in sub-stoichiometric amounts using catalytic Pd(0)/C. Thus, the coupling reactions of various triarylbismuths with a variety of acyl chlorides furnished a plethora of both symmetrical/unsymmetrical aromatic and hetero-aromatic ketones in high yields.     

Chemical Transformations of Tetracyclo[3.3.1.1<Superscript>3,7</Superscript>.0<Superscript>1,3</Superscript>]decane (1,3-Dehydroadamantane): VI. Reactions of 1,3-Dehydroadamantane with Carboxylic Acid Chlorides

1,3-Dehydroadamantane reacted with saturated carboxylic acid chlorides to give the corresponding 1-acyl-3-chloroadmantanes as the major products. In some cases, minor products of insertion into the C^α–H bond of acyl chloride were formed. The reactions of 1,3-dehydroadamantane with aromatic (heteroaromatic) carboxylic acid chlorides selectively afforded aryl (hetaryl) 3-chloroadamantan-1-yl ketones. The described reactions provide a synthetic route to difficultly accessible alkyl (aryl) ketones containing a 3-chloroadamantan- 1-yl group in one step under mild conditions with high yields.