N—二茂铁基—N‘—芳基取代硫脲的合成

Ｎ－二茂铁基－Ｎ＇－芳基取代硫脲的合成袁耀锋王斌王积涛刘娟（南开大学化学系天津３０００７１）（北京联合大学１０００５４）硫脲及其衍生物因具有抗结核活性、除草活性、对植物生长的调节活性等，从５０年代至今一直是人们感兴趣的课题［１］。生物活性测试结果表明...     

用N—取代三氯乙酰胺合成不对称取代脲

以无机碱作催化剂，用三氯乙酰苯胺与不同的胺反应，合成了８种不对称取代脲。     

3—N取代—5—氟脲嘧啶的制备新方法

报道了一种以Ｐｄ－ｃ为催化剂，使２－苄氧基－３－Ｎ－取代－５－氟－４－嘧啶酮在墁常压下氢解制备３－Ｎ－取代－５－氟脲嘧啶的新方法，合成了８个３－Ｎ－取代－５－氟脲嘧啶化合物，其中有些化合物具有一定的抗肿瘤活性。     

液—液相转移催化反应合成N—取代吩噻嗪

本文叙述以四正丁基溴化铵为相转移催化剂,液一液相转移催化合成了六个 N-取代吩噻嗪化合物。由于在方法上作了改进,所以产率均优于文献报导。     

N—芳基—N‘—取代噻唑基脲的合成与结构表征

由于植物细胞分裂素在植物生长发育中非常重要的作用 ,一直得到人们的重视 ,但其天然存在量微难以大量应用 ,故人工合成的化学结构类似物相继出现 ,主要有嘌呤类 ,如 6-苄氨基嘌呤 ( 6-BA)等 [1]和脲类化合物 ,如二苯脲类 ( DPU) [2 ]和N-苯基 -N′-( 1 ,2 ,3 -噻二唑 -5 -基 )脲 ( TDZ) [3]。人工合成嘌呤类植物细胞分裂素的结构改造一般以苯并杂环代替嘌呤环或嘌呤环上取代基进行结构变化 ,脲素细胞分裂素结构改造 ,通常是改变 N-取代基的化学结构 ,为寻找化学结构更类似天然植物细胞分裂素的化合物 ,在合成 N-取代苯基 -N′-( 6-苯…     

N,N—二甲基甲酰胺吸收氮氧化物对取代氨基脲的氧化

Ｎ，Ｎ┐二甲基甲酰胺吸收氮氧化物对取代氨基脲的氧化王彩兰王玉炉＊张深松王晓阳李建平（河南师范大学化学系新乡４５３００２）关键词取代氨基脲，ＤＭＦ－ＮＯｘ，氧化，偶氮脲１９９７－０３－１９收稿，１９９７－０７－０２修回国家自然科学基金，河南省自然科学基...     

N—烷氧甲基取代丙烯酰胺的制备

Ｎ—烷氧甲基取代丙烯酰胺的制备张志成，吴国忠，王胜，徐相凌（中国科学技术大学应用化学系合肥２３００２６）关键词丙烯酰胺，阻聚剂，醚化Ｎ－烷氧甲基取代丙烯酰胺的结构通式为：ＣＨ＿２＝Ｃ－ＣＯＮＨＣＨ＿２ＯＲ＿２Ｒ＿１＝Ｈ．ＣＨ＿３；Ｒ＿２＝Ｈ，Ｍｅ，Ｅ...     

N—取代苯基N′—（6—苯并噻唑基）脲类化合物的合成

为了寻找具有植物细胞激动素活性的新化合物,以苯并噻唑和取代苯胺为原料,将取代苯脲基引入到苯并噻唑的６－位上,合成了７个Ｎ－取代苯基Ｎ′－（６－苯并噻唑基）脲类化合物,它们的结构经元素分析、ＩＲ和＾１ＨＮＭＲ确定,７个化合物的合成收率分别为７４％,７６％,８５％,８２％,７０％,７３％和７２％。     

二氧化碳和丙烯直接合成甲基丙烯酸的NiPMo/TiO2催化剂的研究

用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%.     

CoFe2O4自形成磁性液体场致结构化对磁化的影响

The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula.     

Highly regioselective Buchwald–Hartwig amination at C-2 of 2,4-dichloropyridine enabling a novel approach to 2,4-bisanilinopyridine (BAPyd) libraries

The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines.     

Sulfur-directed metal-free and regiospecific methyl C(sp3)–H imidation of thioanisoles

Regiospecific and direct imidation of the methyl C(sp³)–H bond of thioanisoles is realized under mild and metal-free conditions with N-fluorobis(benzenesulfonyl)imide as an oxidant and nitrogen source. Proposed mechanism suggests that thionium ion intermediates and a Pummerer-type reaction are involved. The imidation has advantages such as high step-economy, excellent functionality tolerance, and regiospecificity, giving structurally diverse imidation products.     

Selective syntheses of 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones via temperature-dependent Rh(II)-carbenoid-mediated 2H-azirine-ring expansion

The Rh(II)-catalyzed reaction of 2-carbonyl-substituted 2H-azirines with ethyl 2-cyano-2-diazoacetate or 2-diazo-3,3,3-trifluoropropionate provides an easy access to 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones. These compounds can be selectively prepared from the same starting material using temperature as the only varied parameter. The 2-azabuta-1,3-diene intermediate, a common precursor for both heterocyclic products, isomerizes into 2H-1,3-oxazine under kinetic control, while 1H-pyrrol-3(2H)-one is the sole product of the reaction at elevated temperatures. According to DFT-calculations a one-atom oxazine ring contraction involving ring-opening to a 2-azabuta-1,3-diene intermediate, followed by a 1,5- and 1,2-prototropic shift leads to the consecutive formation of imidoylketene and azomethine ylide, which then further undergo cyclization to the pyrrole derivative.     

Copper catalyzed/mediated synthetic methodology for ebselen and related isoselenazolones

Scope of the copper catalyzed/mediated selenium-nitrogen coupling reaction has been studied for the synthesis of isoselenazolones. It is noticed that the 2-chloro, 2-bromo-, and 2-iodo-aryl amides substrates can be exploited in the selenium-nitrogen coupling reaction by employing 25-100 mol % of CuI/1,10-phenanthroline (L) and potassium carbonate as a base in DMF. Furthermore, electron rich 2-chloro-arylamides also underwent selenium-nitrogen coupling reaction to give biologically important selenium-nitrogen heterocycles. Also, copper-catalyzed selenium-nitrogen coupling reaction has been meticulously applied for the synthesis of diaryl diselenides having methoxy, amine, and amide functionality from respective aryl iodides in the presence of stoichiometric amount of succinimide as an external Se-N coupling partner.     

Knoevenagel condensation catalyzed by novel Nmm-based ionic liquids in water

A series of novel N-methyl morpholine (Nmm) based ionic liquids with 1,2-propanediol group were synthesized and used as catalysts for Knoevenagel condensation at room temperature in water. Under the effect of the catalyst, various aldehydes or aliphatic ketones could react with a wide range of activated methylene compounds well, including malononitrile, alkyl cyanoacetate, cyanoacetamide, β-diketone, barbituric acid, 2-arylacetonitrile and thiazolidinedione. Furthermore, most of the products could be separated just by filtrating and washing with water. Additionally, the catalyst is recyclable and applicable for the large-scale synthesis.     

Construction of polyheterocyclic spirotetrahydrothiophene derivatives via sulfa-Michael/aldol cascade reaction

A series of polyheterocyclic spirotetrahydrothiophene derivatives were obtained in moderate to excellent yields via a catalyst-free sulfa-Michael/aldol cascade reaction of chalcones 1 and commercially available 1,4-dithiane-2,5-diol 2 under mild conditions. We also present the first asymmetric sulfa-Michael/aldol cascade reaction of chalcones 1 and commercially available 1,4-dithiane-2,5-diol 2 with moderate to good enantioselectivities catalyzed by readily available chiral phase-transfer catalysts (PTCs).     

Suzuki-Miyaura reactions of the soluble guanylate cyclase inhibitor NS2028: a non-product specific route to C-8 substituted analogues

Both soluble guanylate cyclase (sGC) inhibitors ODQ 1 and NS2028 2 are synthesized via improved protocols. In the former case treating 3,4-dihydroquinoxalin-2(1H)-one oxime 8, which can be prepared in two steps from 1,2-benzenediamine, with 1,1′-carbonyldiimidazole (CDI) gives the dihydro-ODQ 10 that in the presence of KMnO₄ oxidises to give ODQ 1 in an overall yield of 46% starting from 1,2-benzenediamine. In the latter case, the synthesis affords NS2028 2 from 2-amino-4-bromophenol 3 in three steps with an overall yield of 85% and avoids the need for chromatography. Furthermore, Suzuki-Miyaura reaction conditions are described that enable the preparation of 8-aryl and 8-heteroaryl derivatives of NS2028 directly from NS2028 2. Finally, demethylation of the 8-(methoxyphenyl) substituted analogues afforded the 8-(hydroxyphenyl) derivatives 40-42. All new products are fully characterised.