一锅法简便合成取代苯氧基苯乙酮

探讨了聚合物支载的铬（Ⅵ）氧化剂、过溴离子及取代苯氧基离子于单锅中以1－苯乙醇为底物,合成苯氧基苯乙酮的方法,并与分步合成法相比较。实验表明,此合成方法具有操作简便、反应条件温和、无须分离中间体、且产率较高等优点,并探索了温度、溶剂、树脂的用量等对一锅法产率的影响。     

一锅法Kumada偶联反应合成烷基吡啶化合物

以溴代吡啶为原料,用简单结构的镍化合物(Py4NiCl2)作为催化剂,经过一锅法Kumada偶联反应合成一系列甲基、烯丙基或苄基取代的吡啶化合物,收率在中等以上.     

两种聚合物试剂应用于单锅合成反应中的研究-取代苯氧基苯乙酮的合成

探讨了聚合物的支载的过溴离子及取代苯氧基离子于单锅中，以苯乙酮为底物，合成取代苯氧基苯乙酮的方法，并与分步合成法相比较。实验表明，此合成方法具有操作简便，瓜条件温和，无须分离中间体，且产率较高等优点，并探索了温度、溶剂、反应时间地脂的用量等对一锅法产率的影响。     

一锅法合成三硫代碳酸酯

以3-巯基丙酸、二硫化碳和氯代烃为原料,采用一锅法分别合成了两种可逆加成-断裂链转移试剂——3-苄硫基硫代羰基硫基丙酸和3-十二烷硫基硫代羰基硫基丙酸,收率分别为93%和87%。其结构经1HNMR,13C NMR,IR及元素分析表征。     

一锅合成法的新进展

综述了最近十余年一锅合成法在有机合成中的主要应用及新进展。参考文献４７篇。     

低价钛化合物催化合成咪唑烷的一锅合成法

本文报道了在低价钛催化下,亚胺类化合物和原甲酸三乙酯发生交叉偶联反应以适中产率制得咪唑烷类化合物,并对所得各种不同取代基的咪唑 烷基化合物的产率和异构体比例进行了讨论。产物的构型用核磁共振波谐进行了表征。     

阿魏酸甲酯的一锅法绿色合成

以香兰素、丙二酸二乙酯为主要原料,以甘氨酸为催化剂,无水甲醇为溶剂,经水解、酸化和Knoevenagel缩合等反应一锅式合成了阿魏酸甲酯。较适宜的反应条件为n(香兰素):n(丙二酸二乙酯):n(甘氨酸)=1.0:1:8:0.15、反应时间8 h、甲醇用量110ml,产率72.3%。     

一锅法合成3-腈基-4苯并吡喃酮类化合物

以各种取代的邻羟基苯乙酮为起始原料,经Vilsmeier试剂环合得中间体3-甲酰基色酮,不经分离纯化,直接与盐酸羟胺反应合成了一系列3-腈基-4苯并吡喃酮类化合物,总收率47%~74%,其结构经1HNMR,IR和MS确证。     

由邻硝基苯胺一锅法合成苯并咪唑化合物

以邻硝基苯胺为原料, 在SnCl2•2H2O/KI/HCl体系中, 100 ℃条件下, 一锅法合成12种苯并咪唑化合物. 该方法以水为溶剂, 条件温和, 操作简单, 催化剂易得, 产率较高, 为该类化合物的合成提供了一种新的便利方法.     

Synthesis of 1-(1,1-dimethylethyl)-1H-pyrazole-4-carboxylate ester derivatives

Attempts to prepare ethyl 5-cyano-1-(1,1-dimethylethyl)-1H-pyrazole-4-carboxylate ( 7 ) by the reaction of the corresponding 5-chloro derivative 1b with cyanide ion were unsuccessful. The chloro ester was synthesized from the corresponding amino ester la utilizing nonaqueous diazotization with nitrosyl chloride. An alternate process was developed which allowed the preparation of 7 from the corresponding 5-methyl ester 3 in four steps. The structure of the N-methylamide 8 synthesized from 7 was confirmed by X-ray diffraction analysis.     

2-[1-(叔丁氧羰基氨基)乙基]噻唑-4-甲酸甲酯的合成

以(S)-丝氨酸和N-Boc-(S)-丙氨酸为原料,经酯化、偶合、TBS保护、硫化、脱保护、环合,脱氢等七步反应,合成了对人体肿瘤细胞KB和LoVo具有中等细胞毒性的天然环酯肽Obyanamide的噻唑结构片段2-[1-(叔丁氧羰基氨基)乙基]噻唑-4-甲酸甲酯,其ee值大于98%,总收率为21.4%.     

5-(4-叔丁氧基羰基哌嗪基)苯并呋喃-2-甲酸乙酯的合成

5-溴苯并呋喃-2-甲酸乙酯与4-叔丁氧基羰基哌嗪进行Buchwald-Hartwig偶联反应,若催化剂是Pd(OAc)2/BINAP,碱是Cs2CO3,则产物主要是5-(4-叔丁氧基羰基哌嗪基)苯并呋喃-2-甲酸乙酯,转化率达70%;若催化剂是Pd(dba)2/P(t-Bu)3,碱是叔丁醇钾,则产物中几乎没有5-(4-叔丁氧基羰基哌嗪基)苯并呋喃-2-甲酸乙酯.文中讨论了影响这个Buchwald-Hartwig偶联反应的因素.     

Synthesis and Crystal Structure of Ethyl 1-（2-bromoethyl）-3-（4-meth-oxyphenyl）-1H-pyrazole-5-carboxylate

The title compound ethyl 1-(2-bromoethyl)-3-(4-methoxyphenyl)-1H-pyrazole-5-carboxylate 1 has been synthesized and structurally characterized by single-crystal X-ray diffraction.The crystal is of monoclinic(C15H17BrN2O3,Mr = 353.22),space group C21 with a = 24.691(7),b = 6.7678(17),c = 17.884(5) ,β = 97.184(5)o,V = 2965.1(13) 3,Z = 8,Dc = 1.583 g.cm-3,F(000) = 1440,μ = 2.784 mm-1,the final R = 0.0260 and wR = 0.0596 for 2684 observed reflections with I > 2σ(I).All the carbon atoms in the molecule are nearly coplanar except C(15),with a large conjugated system among the carbonyl group,pyrazole ring and the benzene ring.Three non-classical intermolecular hydrogen bonds help to stabilize the crystal lattice.The regioselectivity was rationalized based on the coordination of potassium ion with the N-anion and the carbonyl oxygen atom.     

Synthesis of 2-(Tetrazolylacetyl)cyclohexane-1,3-diones

Russian Journal of General Chemistry - 2-(Tetrazolylacetyl)cyclohexane-1,3-diones were synthesized via C-acylation of cyclohexane-1,3-diones with tetrazolylacetic acids in the presence of...     

(2S,4S)-苯甲基-2-(6-氟-1H-吲哚-3-羰基)-4-羟基-吡咯烷-1-羧酸酯的合成

以4-羟基-L-脯氨酸为原料,经Cbz保护、偶联、Mitsunobu反应和水解合成了抗肿瘤新药Birinapant的重要中间体--(2S,4S)-苯甲基-2-(6-氟-1H-吲哚-3-羰基)-4-羟基吡咯烷-1-羧酸酯,总收率83%,其结构经¹H NMR和ESI-MS确证。     

Synthesis of 2-(12-aryldodecanoyl)cyclohexane-1,3-diones

Synthesis was developed of 2-(10-undecenoyl)cyclohexane-1,3-diones containing in the side chain keto and hydroxy groups and a phenyl substituent. The synthesis is underlain by a nitrile oxide approach. The scheme included isoxazole synthesis for the protection of the β,β′-tricarbonyl fragment, building up of a heterocycle by 1,3-dipolar cycloaddition of nitrile oxide in situ to the terminal double bond, cycle opening (of isoxazole and isoxazoline), and alkaline hydrolysis.     

Synthesis and mesomorphic properties of 4-(1,1,7-trihydroperfluoroheptyloxycarbonyl)phenyl 4'-n-alkoxybiphenyl-4-carboxylate

A family of 4-(1,1,7-trihydroperfluoroheptyloxycarbonyl)phenyl 4'-n-alkoxybiphenyl-4-car- boxylates has been synthesized. The compounds show the smectic A phase while the mesogens with intermediate terminal alkyl chain ( n 7-12) also exhibit a broad smectic C phase.     

Synthesis of dirhodium(II) tetrakis[methyl 1-(3-phenylpropanoyl)-2-oxaimidazolidine-4(S)-carboxylate], Rh2(4S-MPPIM)4

The large-scale synthesis with greatly improved yields of methyl 1-(3-phenylpropanoyl)-2-oxaimidazolidine-4(S)-carboxylate and the chiral dirhodium(II) carboxamidate derived from it, Rh₂(4S-MPPIM)₄, is described. The key step in the overall synthesis is the Hofmann rearrangement of Boc-protected l-asparagine, the procedure for which has been modified to achieve near quantitative yield.