固体碱催化环戊酮和碳酸二甲酯合成己二酸二甲酯

以固体酸碱为催化剂,研究了碳酸二甲酯与环戊酮合成己二酸二甲酯的反应,并考察了反应温度、反应时间、催化剂用量和原料摩尔配比等因素对反应结果的影响．结果表明,固体酸催化剂不利于己二酸二甲酯的生成,而具有中强碱位的MgO对反应具有较好的催化性能．当以MgO为催化剂,在反应温度为260℃,反应时间5h,催化剂用量为反应物质量的1．5％,原料摩尔配比为环戊酮／DMC=1／4的最佳条件下,环戊酮的转化率和己二酸二甲酯的选择性分别达到85．5％和50．9％．同时,反应的主要副产物为环戊酮自身缩合的产物（2．环戊烯基环戊酮）以及环戊酮的甲基化产物（2-甲基环戊酮、2-甲基己二酸二甲酯）等．另外,反应是通过固体碱活化环戊酮的α-H进行,而2-甲氧基羰基环戊酮是生成己二酸二甲酯的中间体．     

沸石催化的2,4,4-三甲基-1-戊烯的酰化反应

通过HY沸石与某些传统催化剂的比较，发现HY在2，4，4-三甲基-1-戊烯与乙酸酐的酰化反应中比那些传统催化剂更有效．用HY沸石作催化剂，室温下通过2，4，4-三甲基-1-戊烯与乙酸酐的酰化反应，合成了三种异构体，即4-（2，2-二甲基丙基）-4-戊烯-2-酮、（E）-4，6，6-三甲基-4-庚烯-2-酮和（Z）-4，6，6-三甲基-4-庚烯-2-酮．考察了HY沸石的用量对该酰化反应的影响．当2，4，4-三甲基-1-戊烯／乙酸酐／HY沸石=1mmol／10mmol／0．250g，反应温度25℃、反应时间2h时，生成的三种异构体产率之和为72％，HY沸石对于该反应具有极好的选择性和优良的活性稳定性，不同阳离子交换的Y沸石也用于催化2，4，4-三甲基-1-戊烯的酰化反应。     

1,10-邻菲咯啉-5,6-二酮制备反应中副产物的形成与控制

由1,10-邻菲咯啉合成1,10-邻菲咯啉-5,6-二酮反应的副产物的形成与控制研究表明,1,10-邻菲咯啉在5,6位二酮化反应中的副反应产物及主产物分离时产生的副产物均为4,5-二氮杂芴-9-酮,二酮化反应条件(包括作为氧化剂的强混合酸H2SO4/HNO3的加入量、时间和温度)和主产物分离时体系的酸度对副产物的形成有重要影响,优化了二酮化反应条件和产物分离时的体系pH控制范围。在此优化条件下,可有效控制副产物的形成,使主产物1,10-邻菲咯啉-5,6-二酮的收率达到92%以上。     

β-酮亚胺镍(Ⅱ)配合物体系催化丙烯二聚反应

以乙酰丙酮衍生的β-酮亚胺镍 ( )配合物在烷基铝作用下催化丙烯的二聚反应 ,并考察了铝镍比、烷基铝助剂的种类、不同取代胺配体等对催化性能的影响 .结果表明 ,该体系在一定条件下能高活性 (6 .0× 10 4～1.0× 10 5h- 1 )和较高选择性 (70 %～ 80 % )的催化丙烯二聚反应 ;二聚产物中以 4-甲基戊烯 (4 - MP)为主 ,含部分2 -甲基戊烯 (2 - MP)和己烯 (Hex) ,以及少量的 2 ,3-二甲基丁烯 (2 ,3- DMB)     

5-羟基嘧啶——Ⅴ.1,3-二甲氧基乙酰丙酮与胍和硫脲的缩合

1,3-二甲氧基乙酰丙酮(1)与胍在中性条件下以低产率(28%)缩合生成5-甲氧基-2-氨基-6-甲氧甲基-4-甲基嘧啶(3),而不与硫脲缩合。在与S-甲基异硫脲的反应中,1降解为甲氧基丙酮和甲氧基乙酸,从而生成甲氧基丙酮缩-S-甲基异硫脲甲氧基乙酸盐(4)和S-甲基异硫脲甲氧基乙酸盐(5)。由此可见,1对碱非常敏感,而对酸有一定的稳定性。     

两种天然异戊烯基黄烷酮的全合成

以3-甲氧基甲氧基苯甲醛和2,4,6-三甲氧基-3-异戊烯基苯乙酮为原料,经烷基化和缩合反应合成了新化合物——2’-羟基-4-甲氧基-3,4’,6’-三甲氧甲氧基-3’-异戊烯基査尓酮(6);6经环合反应合成了新化合物——(±)-5,7,3’-三甲氧甲氧基-4’-甲氧基-8-异戊烯基黄烷酮(7);7经脱保护和环合反应实现了天然产物(±)-5,7,3’-三羟基-4’-甲氧基-8-异戊烯基-黄烷酮(1,总收率11.6%)和(±)-5,3’-二羟基-7,8-(2,2-二甲基吡喃)-4’-甲氧基黄烷酮(2,总收率10.5%)的全合成,其中1为新化合物,其结构经1H NMR,IR和MS表征。     

碳酸二甲酯在固体碱上吸附和活化的原位红外光谱研究

采用原位红外技术研究了碳酸二甲酯在氧化镁、氟化镁、镁铝复合氧化物和氟改性的镁铝复合氧化物4种固体碱表面上的吸附和活化行为。结果表明:碳酸二甲酯以单、双齿两种形态吸附于固体碱的表面,双齿吸附的比单齿吸附的更易活化。碳酸二甲酯吸附于氧化镁和镁铝复合氧化物上活化生成甲氧基,吸附于氟化镁上活化生成甲氟基;而吸附于氟改性的镁铝复合氧化物上优先活化生成甲氟基,随着吸附表面温度的升高,逐渐有甲氧基生成,说明氟改性的镁铝复合氧化物是一种优良的甲基化反应催化剂。     

(－)-7(R)-羟罗汉脂素的全合成研究

以4-戊烯酸及(R)-4-苯基-2-噁唑烷酮为起始原料, 以氯化镁在三乙胺和三甲基氯化硅存在下催化的(R)-4-苯基-3-戊烯酰基-2-噁唑烷酮的埃文斯（Evans)反式羟醛缩合反应为关键步骤, 经9步反应合成了(－)-7(R)-羟罗汉脂素, 其光谱数据与文献报道的天然产物一致.     

V2O5/SiO2催化剂的异丁烷选择氧化反应性能

 采用溶胶－凝胶法和浸渍法制备了V2O5／SiO2催化剂,并用XRD,IR,TPD和活性评价等手段对催化剂的表面构造、化学吸附性能和异丁烷选择氧化反应性能进行了研究．结果表明：催化剂表面由Lewis碱位V＝O双键的端氧和Lewis酸位V5＋构成,异丁烷分子主要通过甲基中的H双位吸附在催化剂表面的Lewis碱位上,异丁烯分子可通过甲基的H吸附在催化剂表面的Lewis碱位,也可通过C＝C双键吸附在催化剂表面的Lewis酸位上．在常压条件下,异丁烷选择氧化产物主要有异丁烯、甲基丙烯醛和甲基丙烯酸,其中深度氧化产物CO2主要由通过C＝C吸附的异丁烯继续反应生成．     

一种新的质子泵抑制剂苯并咪唑衍生物的合成与表征

以2-巯基苯并咪唑为原料,在碱性条件下与自制的盐酸2-氯甲基-4-(3-甲氧基丙氧基)-3-甲基吡啶缩合得2-{[4-(3-甲氧基丙氧基)-3-甲基吡啶-2-基]甲基硫}-1H-苯并咪唑,再经氧化、成盐反应生成产物2-{[4-(3-甲氧基丙氧基)-3-甲基吡啶-2-基]甲基亚硫酰基}-1H-苯并咪唑钠,总收率66%.此产物通过红外光谱、核磁共振、质谱表征加以确认.     

Reaction of hexafluoropropylene and its oligomers with acetone oxime

Reactions of perfluoropropylene and its oligomers with acetone oxime in the presence of a base afford perfluoroalkyl and/or perfluoroalkenyl ethers of acetone oxime. When heated to 100 °C, the 3-perfluoro-2-methyl-2-pentenyl ether of acetone oxime (3) is quantitatively converted to 4-hydroxy-3-methyl-5,5-bistrifluoromethyl-4-pentafluoroethyl-1-pyrroline (4), the structure of which was established by X-ray diffraction analysis. A convenient one-stage synthesis of perfluoro-3-isopropyl-4-methyl-3-penten-2-one (7) was proposed.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1068–1072, June, 1994.     

Synthesis of Mesityl Oxide π-Complexes with Metals of Chromium Subgroup and with Iron. Theoretical and Experimental Investigation of the Ligand Dissociation Energy

At the use of photochemical and thermochemical activation new π-complexes of chromium, molybdenum, and tungsten were prepared containing in the coordination sphere η²- and η⁴-molecules of 4-methyl-3-penten-2-one. Nonempirical methods were applied to calculation of the energy parameters of the coordinated molecules, and the factors governing the η²- and η⁴-coordination of the oxodiene system were established. A thermochemical study was performed on the 4-methyl-3-penten-2-one η⁴-coordination product with carbonyl metal core. A scheme of the thermal decomposition was suggested for the iron (0) η ⁴-(4-methyl-3-penten-2-one)tricarbonyl.__________Translated from Zhurnal Organicheskoi Khimii, Vol. 41, No. 5, 2005, pp. 665–671.Original Russian Text Copyright © 2005 by Kuramshin, Kuramshina, Cherkasov.     

Synthesis of functional derivatives of trifluoromethylpyrimidines from acetylacetone,trifluoroacetonitrile, and aryl isocyanates

1, 1,1-Trifluoro-2-amino-3-acetyl-2-penten-4-one was obtained by the addition of acetylacetone to trifluoroacetonitrile in the presence of catalytic amounts of nickel acetylacetonate. The reaction of 1,1,1-trifluoro-2-amino-3-acetyl-2-penten-4-one with aryl isocyanates gave 1-aryl-5-acetyl-6-methyl-4-trifluoromethyl-1H-pyrimidin-2-ones.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 11, pp. 2639–2642, November, 1991.     

The synthesis of polymethylquinolines and 1,10-phenanthrolines

Several polymethyl-1,10-phenanthrolines were synthesized by the use of 3-methyl-3-penten-2-one in Skraup reactions. The behavior of this ketone as well as that of 4-hydroxy-2-pentanone and 4-hydroxy-3-methyl-2-bulanone with various substituted anilines was studied.     

3-甲基-2-戊烯-4-炔醛的合成新方法

化合物3-甲基-2-戊烯-4-炔-1-醛两端均为活性官能团,在分子连接及成环反应中能够起到非常重要的作用,是合成轮烯酮[1-7],脱落酸[8]和二苯基二苯并环辛烯[9]等的重要中间体.     

The Clemmensen Reduction of α, β-Unsaturated Ketones

Eleven structurally different α, β-unsaturated ketones were subjected to the Clemmensen reduction under anhydrous conditions using amalgamated zinc, hydrogen chloride in a solution of ethyl ether, and acetic anhydride. In all cases but one the formation of cyclopropyl acetates was observed. 4-Methyl-3-penten-2-one, methyl vinyl ketone, 2-isopropylidene-1-cyclopentanone, and 2-cyclohepten-1-one led to substituted cyclopropyl acetates. Stereospecific reactions were found with 2-ethylidene-1-cyclopentanone, 2-benzylidene-1-cyclohexanone, and methyl 1-cyclohexenyl ketone, whereas 3-penten-2-one, 3-methyl-3-buten-2-one, and 2-methyl-2-cyclohexen-1-one afforded mixtures of the isomeric cyclopropyl acetates. These results are interpreted in terms of the intital formation of an allylic anion which undergoes electrocyclic closure. A stereospecific course is followed when geometric constraints permitted. Exceptions are discussed.     

Reaction of 4,5-diaminopyrimidine and ethyl acetoacetate: Synthesis and chemistry of isomeric dihydropyrimido[4,5-b][1,4] diazepinones

Depending upon reaction conditions, 4,5-diaminopyrimidine and acetoacetic ester gave a variety of condensation products, including the two isomeric dihydropyrimido[4,5-b][1,4]-diazepinones. Under conditions leading to bicyclic products, the formation of 1,5-dihydro-4-methyl-2H-pyrimido[4,5-b][1,4]diazepin-2-one ( 2 ) was strongly favored. The isomeric 3,5-dihydro-2-methyl-4H-4-one compound ( 4 ) was best obtained by cyclization of ethyl 3-(4-amino-5-pyrimidylamino)crotonate ( 3 ) under base catalysis. Thermal rearrangement of 2 and 4 proceeded, in each instance, with loss of the isopropenyl moiety and gave 8-purinone. Compound 4 underwent ring contraction under the influence of alkoxide to yield a product which was shown to be the 7-isopropenyl-8-purinone ( 6 ).     

Reaction of ketenes with N,N-disubstituted α-aminomethyleneketones. X. Synthesis of N,N-disubstituted 6-alkyl-4-amino-3,3-dichloro-3,4-dihydro-2H-pyran-2-ones and of 6-alkyl-4-amino-3-chloro-2H-pyran-2-ones

Cycloaddition of dichloroketene to N,N-disubstituted 1-amino-4-methyl-1-penten-3-ones and 1-amino-4,4-dimethyl-1-penten-3-ones occurred in moderate to fair yield only in the case of aromatic N-substitution to give N,N-disubstituted 6-alkyl-4-amino-3,3-dichloro-3,4-dihydro-2H-pyran-2-ones, which were dehydrochlorinated with DBN to afford in good yield N,N-disubstituted 6-alkyl-4-amino-3-chloro-2H-pyran-2-ones. In the case of aliphatic N,N-disubstitution, cyclo-addition led directly to 6-alkyl-4-dialkylamino-3-chloro-2H-pyran-2-ones only for N,N-disubstituted 1-amino-4,4-dimethyl-1-penten-3-ones. The reaction between 1-dimethylamino-4-methyl-1-penten-3-one and dichloroketene gave 3-chloro-4-dimethylamino-3,6-dihydro-6-isopropylidene-2H-pyran-2-one in low yield.     

Steric and polar effects in free-radical reactions. - An unusual type of azocoupling by free radical decomposition of diazonium salts

A new free-radical azocoupling has been accomplished by decomposition of diazonium salts with monoelectronic reducing agents in the presence of 4-methyl-3-penten-2-one. Steric and polar factors are responsible of the unusual behaviour.     

Synthesis and reactions of (E)-1,1,1-trifluoro-2-methyl-2-penten-4-ylidene-malonodinitrile

Condensation of (E)-1,1,1-trifluoro-2-methyl-2-penten-4-one with malonodinitrile affords mixtures of unsaturated nitriles. Attempted cyclization of these nitriles in concentrated sulfuric acid furnishes derivatives of alkylidenecyanoacetamides and alkylidenemalonodiamide.