聚苯乙烯固载聚乙二醇催化环己烯与二氯卡宾的加成反应

本文报道了聚苯乙烯固载聚乙二醇催化环己烯与二氯卡宾的加成反应，考察了聚乙二醇固载前后的催化活性、聚苯乙烯国载聚乙二醇上的聚乙二醇摩尔量、催化剂用量和反应时间等对产品收率的影响，并对催化剂的重复使用活性进行了研究。催化剂首次使用，产品７，７－二氯双环［４，１，０］庚烷的收率为８５．４％。     

癸二酸二辛酯非酸性催化合成

以癸二酸与２－乙基己醇为原料，铝酸盐为催化剂，合成了癸二酸二辛酯。考察了影响合成收率的各种因素。在醇酸摩尔比为２．５∶１、催化剂用量为０．０４～０．０５％、反应温度２２０～２３０℃及反应时间２．５ｈ的最佳条件下，产品收率＞９８％。     

2‘,7’—二氯荧光素荧光法测定环境水样中的酚

报道了以２＇，７＇－二氯荧光素（ＤＣＦ）为指示剂，荧光法间接测定痕量酚的新方法。在０．５ｍｏｌ／Ｌ Ｈ２ＳＯ４介质中，Ｂｒ＾－和ＢｒＯ３＾－反应生成Ｂｒ２，Ｂｒ２与２＇，７＇－二氯荧光素反应，使２＇７＇－二氯荧光素荧光猝灭，当加入酚时，酚的溴代反应使体系荧光增强。ｐＨ４．０￣６．０范围内，该体系激发波长，发射波长分别为λｅｘ５０５ｎｍ，λｅｍ５２０ｎｍ。酚浓度在１．６￣５２ｎｇ／Ｌ范围内呈线性关系     

2′,7′-二氯荧光素荧光法测定环境水样中的酚

报道了以２′，７′－二氯荧光素（ＤＣＦ）为指示剂，荧光法间接测定痕量酚的新方法。在０．５ｍｏｌ／ＬＨ２ＳＯ４介质中，Ｂｒ－和ＢｒＯ－３反应生成Ｂｒ２，Ｂｒ２与２′，７′－二氯荧光素反应，使２′７′－二氯荧光素荧光猝灭，当加入酚时，酚的溴代反应使体系荧光增强。ｐＨ４．０～６．０范围内，该体系激发波长，发射波长分别为λｅｘ５０５ｎｍ，λｅｍ５２０ｎｍ。酚浓度在１．６～５２ｎｇ／Ｌ范围内呈线性关系，检出限为１．６ｎｇ／Ｌ。本法选择性好，用于环境水样中酚的测定，结果满意。     

1．4──二氢吡啶类钙拮抗剂的合成法研究Ⅲ非洛地平的合成

在无水氯化锌的存在下，２，３－二氯苯甲醛与乙酰乙酸甲酯经Ｋｎｏｅｖｅｎａｇｅｌ－Ｄｏｅｂｎｅｒ缩合反应，制成２，３－二氯亚苄基乙酰乙酸甲酯（２），继而与３－氨基丁烯酸甲酯在阳离子交换树脂Ｄ６１的催化下进行环合Ｍｉｃｈａｅｌ加成反应，得非洛地平（１），以２，３－二氯苯甲醛计算，总收率７６．５％。探计了无水氯化锌的用量，反应温度对２收率的影响，还考察了不同阳离子交换成树脂对１的收率和质量的影响。     

聚氯乙烯三氯化铁树脂催化合成肉桂酸甲酯

在聚氯乙烯三氯化铁催化下由肉桂酸和甲醇发生酯化合成了肉桂酸甲脂,当０．０２ｍｏｌ．肉桂酸,０．１０ｍｏｌ甲醇和１．５ｇ催化剂一起回流加热７．０ｈ时,产品收率达８４．４％。     

改进的2-巯基-5-甲氧基咪唑并[4,5-b]吡啶合成法

以2,6-二氯吡啶为起始原料,经甲氧基化、硝化、氨基化、还原及成环5步反应得到2-巯基-5-甲氧基咪唑并[4,5-b]吡啶,总收率45.7%。重点比较了2-氯-6-甲氧基吡啶和2,6-二氯吡啶硝化反应条件及收率的差异,讨论了水合肼、NaOH的用量对目标产物收率的影响。用1HNMR、MS和IR测试技术对目标产物结构进行了表征。     

聚苯乙烯固载聚乙二醇-600催化合成肉桂酸

本文采用固载化聚乙二醇-600为相转移催化剂，高收率地合成了肉桂酸，并对催化剂用量，反应时间和催化剂的重复使用性能对产品收率的影响进行了研究．     

铌酸催化液相合成乙酸乙酯

报道了铌酸催化乙醇与乙酸的液相酯化反应考察了反应温度、催化剂用量、酸醇比、反应时间对产品乙酸乙酯经的影响。在优化条件下,产品收率棕达８８．０％,选择性为１００％,同时我们采用自制间式反应,对催化剂的稳定性进行了考察,发现铌酸在该实验条件下,能保持较高的稳定性和较高的催化活性。     

1,4-二乙氧基苯的相转移催化合成

采用大孔型交联聚苯乙烯为载体研究制得新型季Lin盐型相转移催化剂Y98B，并将其于1，4－二乙氧基苯的催化合成反应，进行了产品的红外光谱分析和熔点测定，探讨了催化剂用量、对苯二酚与溴乙烷物的质量比、反应温度和反应时间等动力学条件对产品收率的影响。确定了在反应温度为70℃,mol对苯二酚：mol溴乙烷＝1：3．5，反应时间4h，催化剂用量3．0g的条件下产品收率可达84.3%。     

Transformations of halocyclopropanes—VII : Reactions of 7,7-dichlorobicyclo[4.1.0] heptane with carbanions

The reactions of 7,7-dichlorobicyclo[4.1.0] heptane 1 were carried out with C-H acids in the presence of t- BuOK in DMSO. The respective syn-7-chlorobicyclo[4.1.0] heptane derivatives 3 were the major products of the reactions with diethyl malonate and ethyl cyanoacetate. The dehydrochlorinated material α-bicyclo[4.1.0] hepten-5-yl-α-phenylpropionitrile 5c, was obtained in good yield in the reaction with α-phenylpropionitrile.     

Reaction of gem-dibromocyclopropanes with diphenylphosphide ion

Diphenylphosphide ion undergoes a photostimulated reaction with 7,7-dibromobicyclo[4.1.0]heptane and 1,1-dibromo-2,2,3,3-tetramethylcyclopropane involving both ionic and radical steps to afford cyclopropyldiphenylphosphines resulting from substitution and reduction.     

Synthesis and properties of 7,7-dichloro-3,4-benzobicyclo[4.1.0]heptane, its tricarbonylchromium complexes, and isomeric 7-chloro-3,4-benzobicyclo[4.1.0]heptanes

The reaction of Cr(CO)₆ with 7,7-dichloro-3,4-benzobicyclo[4.1.0]heptane gave the correspondingexo- andendo-chromium tricarbonyl complexes in a ratio of 4.5:1. The structures of the resulting compounds were established by NMR spectroscopy, mass spectrometry, and X-ray structural analysis. Reduction of dichlorobenzobicycloheptane and its chromium tricarbonyl complexes with LiAlH₄ affordedexo- andendo-7-chloro-3,4-benzobicyclo[4.1.0]heptanes in a 3.5:1 ratio. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 4, pp. 720–724, April, 1998.     

Dehydrochlorination of chloroform by N-methyl-N,N-bis(silatranylmethyl)amine

N,N-Bis(silatranylmethyl)methylamine 1 reacts with chloroform resulting in amine hydrochloride 2 and dichlorocarbene. The formation of the latter was proved by a cyclopropanation reaction and insertion into the Si-H bond. In the presence of cyclohexene, compound 2 and 7,7-dichlorobicyclo[4.1.0]heptane are the major reaction products. Compound 2 and 1-dichloromethylsilatrane were isolated upon the reaction of amine 1 with chloroform and 1-hydrosilantrane.     

Reaction of 2-methyl-5,6-dihydro-2H-pyran with dichlorocarbene

Upon treatment of 2-methyl-5,6-dihydro-2H-pyran with dichlorocarbene there are formed products of addition to the double bond and insertion at the C-H bond giving cis- and trans-7,7-dichloro-2-methyl-3-oxabicyclo[4.1.0]heptane and 2-dichloromethyl-2-methyl-5,6-dihydro-2H-pyran.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 190–191, February, 1986.     

Theoretical Study of the Photochemical Reaction Mechanism of Bicyclo [4.1.0 ] heptane

IntroductionPhotochemical reactions, which involve a three-membered ring, have been of great interest to experi-mental photochemists[1—10]. A main reason for thisphenomenon is that the cyclopropane ring exhibits somereaction characteristics of double bon…     

Synthesis of a Chiral Bicyclo[4.1.0] Allylic Nitrile Via Reductive Cyclization of a Dienyl Nitrile

(1R, 6S)-7,7-dimethylbicyclo[4.1.0]Hept-2-ene-3-acetonitrile 8 was synthesized from (S)-(-)-Perillaldehyde in 5 steps and 65% overall yield via Mg[0] reductive cyclization.     

Formation of titanacyclobutenes with a spiro-bonded cyclopropane

The reaction of titanium cyclopropylidene complexes, prepared by the reductive titanation of 7,7-dichlorobicyclo[4.1.0]heptanes, with alkynes produced air and moisture stable titanacyclobutenes with a spiro-bonded cyclopropane.     

Substituted 2,5-diazabicyclo[4.1.0]heptanes and their application as general piperazine surrogates: synthesis and biological activity of a Ciprofloxacin analogue

Piperazines and modified piperazines, such as homopiperazines and 2-methylpiperazines, are found in a wide range of pharmaceutical substances and biologically active molecules. In this study 2,5-diazabicyclo[4.1.0]heptanes, in which a cyclopropane ring is fused onto a piperazine ring, are described as modified piperazine analogues. Differentially N,N′-disubstituted and N-monosubstituted compounds can be readily prepared from 2-ketopiperazine in a few steps, using a Simmons-Smith reaction of 1,2,3,4-tetrahydropyrazines with diethylzinc and diiodomethane for the key cyclopropane ring formation. An analogue of the fluoroquinolone antibacterial Ciprofloxacin was synthesized using a palladium-catalyzed Buchwald-Hartwig cross-coupling to attach the diazabicyclo[4.1.0]heptane core to the 7-position of the fluoroquinolone core. The resultant analogue was demonstrated to have similar antibacterial activity to the parent drug Ciprofloxacin. X-ray crystallographic analysis of this analogue reveals a distorted piperazine ring in the diazabicyclo[4.1.0]heptane core. The pK_a of the conjugate acid of N-Cbz-monoprotected 2,5-diazabicyclo[4.1.0]heptane was determined to be 6.74±0.05, which is 1.3 pK_a units lower than the corresponding N-Cbz-monoprotected piperazine compound. The lower basicity of diazabicyclo[4.1.0]heptanes is due to the electron-withdrawing character of the adjacent cyclopropane rings. The modified physicochemical and structural properties of diazabicyclo[4.1.0]heptanes relative to piperazines are expected to lead to interesting changes in the pharmacokinetic and biological activity profile of these molecules.     

Transformations of halocyclopropanes-VI: Reactions of 7,7-dichlorobicyclo[4.1.0]heptane with some organic anions in nonpolar media

The reactions of 7,7-dichlorobicyclo-[4.1.0]heptane, 1 with organic bases were carried out in benzene and THF. The reaction course of 1 in nonpolar media is different from that in DMSO; the rearrangements of cyclopropene 3 taking place in the former. 8 is produced by the shift of double bond into the C₆ ring. The cyclopropene-carbene isomerization and reactions of carbenes 14 and 15 with alkoxide anions are the probable route leading to the other products.