无外加催化剂条件下邻取代芳香醛与5, 5-二甲基-1, 3-环己二 酮的反应研究

在DMF溶剂中,不外加催化剂使邻取代芳香醛(1)与5,5-二甲基-1,3-环己二酮(2)发生缩合和加成反应生成3,3,6,6-四甲基-4a-羟基-9-芳基-1,8-二氧代-2,3,4,4a,5,6,7,8,9,9a-十氢化-1H-氧杂蒽(3a-3d)。在同样条件下,邻羟基芳香醛与5,5-二甲基-1,3-环己二酮则发生缩合、加成和脱水反应生成3,3-二甲基-9-(5,5-二甲基-3-羟基-2-环己烯-1-酮-2-基)-1-氧代-2,3,4,9-四氢化-1-氧杂蒽(4a-4b)。用单晶X-射线分析法确定了产物3a和4a的晶体结构。     

无外加催化剂条件下邻取代芳香醛与5,5-二甲基-1,3-环己二酮的反应研究

在DMF溶剂中,不外加催化剂使邻取代芳香醛(1)与5,5-二甲基-1,3-环己三酮(2)发生缩合和加成反应生成3,3,6,6-四甲基-4a-羟基-9-芳基-1,8二氧化-2,3,4,4a,5,6,7,8,9a-十氢化-1H氧杂蒽(3a～3d)。在同样条件下,邻羟基芳香醛与5,5-二甲基-1,3-环己三酮则发生缩合,加成和脱水反应生成3,3-二甲基-9-(5,5-二甲基-3-羟基-2-环己烯-1-酮-2-基)-1-氧代-2,3,4,9-四氢化-1 氧杂蒽(4a～4b)。用单晶X-射线分析法确定了产物3a和4a的晶体结构。     

微波辐射下芳醛与5, 5-甲基-1, 3-环己二酮的固相和液 相反应

芳醛(1)与5,5-二甲基-1,3-环己二酮(2)在固相条件下,经微波辐射得到3,而在乙二醇溶剂中,经微波辐射得到4,产率接近定量。     

无外加催化剂条件下2-氨基-3-腈基-4-芳基-7,7-二甲基-5-氧 代-4H-5,6,7,8- 四氢苯并-[b]-吡喃-3-羧酸乙酯的合成

亚苄基氰基乙酸乙酯(1)与5,5-二甲基-1,3-环已二酮在乙二醇中不加任何催化剂于80℃反应2～3h得2-氨基-4-芳基-7,7-二甲基-5-氧化-4H-5,6,7,8-四氢苯并-[b]-吡喃-3-羧酸乙酯(3),产率75%～93%。     

无外加催化剂条件下芳香醛与活性亚甲基化合物的缩合反应和迈克尔加成反应

在DMF溶剂中，不外加催化剂使芳香醛(1)与2,2-二甲基-1,3-二氧六环-4,6-二酮(2)发生缩合反应生成2,2-二甲基-5-芳亚甲基-1,3-二氧六环-4,6-二酮(3a～f)。在同样条件下，芳香醛与5,5-二甲基-1,3-环己二酮(4)则发生缩合和迈克尔加成反应生成2,2'-芳亚甲基双(3-羟基5,5-二甲基-2-环己烯-1-酮)(5a～h)。用单晶X-射线分析法确定了产物5b的晶体结构。     

无外加催化剂条件下芳香醛与活性亚甲基化合物的缩合反应和迈克尔加成反应

在DMF溶剂中,不外加催化剂使芳香醛(1)与2,2-二甲基-1,3-二氧六环-4,6-二酮(2)发生缩合反应生成2,2-二甲基-5-芳亚甲基-1,3-二氧六环-4,6-二酮(3a～f)。在同样条件下,芳香醛与5,5-二甲基-1,3-环己二酮(4)则发生缩合和迈克尔加成反应生成2,2’-芳亚甲基双(3-羟基-5,5-二甲基-2-环己烯-1-酮)(5a～h)。用单晶X-射线分析法确定了产物5b的晶体结构。     

芳亚甲基双(3-羟基-5,5-二甲基-2-环己烯-1-酮)类化合物的合成

在水溶剂中,酸性离子液体[bmim][HSO4]可以有效地催化芳香醛与5,5-二甲基-1,3-环己二酮反应3～5h,得到产率为76%～86%的芳亚甲基双(3-羟基-5,5-二甲基-2-环己烯-1-酮)类化合物.该反应产物后处理简单,催化剂可以回收利用.催化剂在循环使用五次时对产物的收率影响不大,是一种环境友好的绿色合成方法.     

微波辐射一步法合成吡喃和吡喃[2, 3-c]吡唑衍生物

芳醛、丙二腈与5,5-二甲基-1,3-环己二酮或3-甲基-1-苯基-2-吡唑啉-5-酮在乙醇溶剂中用哌啶作催化剂,经微波辐射一步合成了2-氨基-3-氰基-4-芳基-7,7-二甲基-5-氧代-5,6,7,8-四氢苯并吡喃和6-氨基-5-氰基-4-芳基-1,4-二氢吡喃[2,3-c]吡唑,反应在2～12min内完成,产率53%～91%。     

离子液体1-乙基-3-丁基磺酸咪唑对甲苯磺酸盐催化合成氧杂蒽

以1-乙基咪唑为原料,合成了布朗斯特酸性离子液体--1-乙基-3-丁基磺酸咪唑对甲苯磺酸盐(IL1),并将其用于催化芳香醛与5,5-二甲基-1,3-环己二酮或1,3-环己二酮在无溶剂条件下合成了系列氧杂蒽类化合物,其结构经¹H NMR, ¹³C NMR和ESI-MS表征。研究结果表明：当IL1用量为5 mol%,于80 ℃反应40 min,收率78%~95%; IL1循环使用3次,收率86%~89%,催化活性无明显变化。     

KF-蒙脱土催化下2-氨基-3-氰基-4-芳基-7,7-二甲基-5-氧代-4H-5,6,7,8-四氢苯并[b]吡喃的合成

以KF-蒙脱土为催化剂, 取代肉桂腈与5,5-二甲基-1,3-环己二酮在95%乙醇中回流反应得2-氨基-3-氰基-4-芳基-7,7-二甲基-5-氧代-4H-5,6,7,8-四氢苯并[b]吡喃, 此方法快速、方便、高效, 同时考察了溶剂、催化剂对反应的影响.     

2-氯-2-氧代(硫代)-1, 3, 2-二氧磷杂环己烷的甲醇解及其开环 异构化反应

报道了trans-2-氧代-2-氯-4-苯基-5,5-二甲基-1,3,2-二氧磷杂环己烷以及cis-2-硫代-2-氯-4-苯基-5,5-二甲基-1,3,2-二氧磷杂环己烷甲醇解反应的立体化学。结果表明,反应体系的酸碱性对前者甲醇解反应的立体化学有着重要影响。而硫代环磷酰氯在碱性条件下的甲醇解反应存在一个开环异构化过程。     

Reactions of dialkyl 4-bromo-2,2-dimethyl-3-oxohexane-1,6-dioates,-heptane-1,7-dioates with zinc and aromatic aldehydes

Zinc enolates generated from dimethyl 4-bromo-2,2-dimethyl-3-oxohexane-1,6-dioate and zinc reacted with aromatic aldehydes giving methyl 2,2-dimethyl-3-oxo-3-(5-oxo-2-aryltetrahydrofuran-3-yl)propanoates. The reaction of zinc enolates obtained from dimethyl 4-bromo-2,2-dimethyl-3-oxoheptane-1,7-dioate and zinc with aromatic aldehydes depending on the synthesis conditions led to the formation either methyl 2,2-dimethyl-3-oxo-3-(6-oxo-2-aryltetrahydropyran-3-yl)propanoates or 3-(5,5-dimethyl-4,6-dioxo-2-aryltetrahydropyran-3-yl)propanoates. The compounds synthesized formed as a single diastereomer of E-configuration.     

2－甲基－3－芳基－7－（5，5－二甲基－3－酮－1－环己烯－1－基）甲酸酯－4（3H）－喹唑啉酮的合成

以2－氨基对苯二甲酸（1）为起始原料，与乙酸酐缩合生成7－羧基乙酰苯邻 甲内酰胺（2）；2和芳胺缩合产生7－羧基－2－甲基－3－芳基－4（3H）－喹唑啉 酮（3）；3和N，N－双环己基碳双亚胺（DCC）加成得到中间体4，4在4－二甲氨基 吡啶（DMAP）催化下和5，5－二甲基－1，3－环己二酮（5）缩合得到目标产物2－ 甲基－3－芳基－7－（5，5－二甲基－3－酮－1－环己烯－1－基）甲酸酯－4（ 3H）－喹唑啉酮（6）。所得15个新型化合物的结构均经^1H NMR、元素分析确证， 部分化合物经IC／MSD确证。     

A Convenient Synthesis of 3-Aryl-3-(5,5-dimethyl-3-hydroxy-2-cyclohexene-1-one-2-yl) Propanic Esters Catalyzed by KF-Alumina

A series of 3-aryl-3-(5,5-dimethyl-3-hydroxy-2-cyclohexene-1-one-2-yl) propanic esters were synthesized by reaction of aromatic aldehydes, 5,5-dimethyl-1,3-cyclohexanedione and isopropylidene malonate in alcohols catalyzed by KF-Al₂O₃. The structure of 4a was determined by X-ray analysis.     

1,7-dithioxo systems. Reaction of 3-[(5,5-dimethyl-3-thioxocyclohex-1-en-1yl)sulfanyl]-5,5-dimethylcyclohex-2-ene-1-thione with 2-aminoethanol and ethane-1,2-diamine

The reaction of 3-[(5,5-dimethyl-3-thioxocyclohex-1-en-1-yl)sulfanyl]-5,5-dimethylcyclohex-2-ene-1-thione with 2-aminoethanol involves cleavage of the sulfide bond with formation of 3-[(2-hydroxyethyl)-amino]-5,5-dimethylcyclohex-2-ene-1-thione as the major product. The reaction of the same sulfide with ethane-1,2-diamine gave previously unknown 3-({2-[(5,5-dimethyl-3-thioxocyclohex-1-en-1-yl)amino]ethyl}-amino)-5,5-dimethylcyclohex-2-ene-1-thione.     

Reformatsky Reaction of Methyl α-Bromoisobutyrate with 2-Arylmethylidenemalonic Acid Derivatives

Reformatsky reagent obtained by treatment of methyl α-bromoisobutyrate with zinc reacts with dimethyl 2-arylmethylidenemalonates to give trimethyl 2-aryl-3-methylbutane-1,1,3-tricarboxylates. The reaction of the same compound with ethyl 3-aryl-2-(4-methylphenylcarbamoyl)acrylates yields cyclic products, ethyl 4-aryl-5,5-dimethyl-1-(4-methylphenyl)-2,6-dioxopiperidine-3-carboxylates. Treatment of the latter with morpholine and phenylhydrazine leads to the corresponding 4-aryl-5,5-dimethyl-1-(4-methylphenyl)-2,6-dioxopiperidine-3-carboxylic acid morpholides and phenylhydrazides. The products are formed as a single diastereoisomer.__________Translated from Zhurnal Organicheskoi Khimii, Vol. 41, No. 7, 2005, pp. 1034–1038.Original Russian Text Copyright © 2005 by Shchepin, Fotin.     

An Efficient Synthesis of N‐Substituted‐3‐aryl‐3‐(2‐hydroxy‐4,4‐dimethyl‐6‐oxocyclohex‐1‐enyl)propanamides by Four‐component Reaction in Aqueous Medium

A mild and efficient synthesis of N‐substituted‐3‐aryl‐3‐(2‐hydroxy‐4,4‐dimethyl‐6‐oxocyclohex‐1‐enyl)propanamides via four‐component reaction of an aldehyde, amine, Meldrum's acid and 5,5‐dimethylcyclo‐hexane‐1,3‐dione in the presence of benzyltriethylammonium chloride (TEBAC) in aqueous medium is described. This method has the advantages of accessible starting materials, good yields, mild reaction conditions and eco‐friendliness.     

Reduction of 5-(bromomethyl)-1-pyrrolinium bromides to 2-(bromomethyl)pyrrolidines and their transformation into piperidin-3-ones through an unprecedented ring expansion-oxidation protocol

3,3-Dialkyl-5-(bromomethyl)-1-pyrrolinium bromides, prepared via bromocyclization of N-(2,2-dialkyl-4-pentenylidene)amines by means of bromine in dichloromethane, were reduced to 4,4-dialkyl-2-(bromomethyl)pyrrolidines for the first time using borane dimethyl sulfide in dichloromethane. Furthermore, the latter 2-(bromomethyl)pyrrolidines were transformed into the corresponding piperidin-3-ones through an unprecedented ring expansion-oxidation protocol in dimethylsulfoxide in the presence of potassium carbonate. Reduction of 5,5-dialkylpiperidin-3-ones by means of sodium borohydride in methanol afforded 5,5-dialkyl-3-hydroxypiperidines in good yields.