单-6-脯氨酸-β-环糊精的合成

以β-环糊精为原料,经对甲苯磺酰化、叠氮化、还原氨基后,再与Boc保护的脯氨酸进行肽键缩合和脱Boc保护基,合成了单-6-脯氨酸-β-环糊精,其结构经1H NMR表征.     

Boc或Cbz保护的L-脯氨醇衍生物的稳定性

近年来,L-脯氨醇衍生物催化的不对称Michael加成反应已经成为手性催化研究领域的热点.而在L-脯氨醇衍生物的合成中,常常涉及到L-脯氨醇氨基的保护.为此,研究了Boc和Cbz保护的脯氨醇衍生物的稳定性,发现Boc保护的L-脯氨醇在羟基被取代为易离去基团时,就变得不稳定,在67℃就发生分子内环合生成化合物y-丁内酯;而Cbz保护的L-脯氨醇衍生物的稳定性要好得多,在140℃且有三乙胺存在时,才会发生类似的分子内环合反应.     

高活性脯氨酰胺类化合物的合成及催化Michael加成反应的研究

以L-脯氨酸为原料,通过上保护基,酯化,氨化,脱保护基等步骤合成BOC-L-脯氨,再与苯甲酸与萘酚酸等衍生物在无水无氧条件下合成了高活性脯氨酰胺类有机小分子催化剂,并用于催化二苯乙烯基酮衍生物与蒽酮的加成反应,产率高达80%以上,同时还考察了不同条件下对催化产率的影响。该加成反应条件温和,操作简便且产率高。     

α-氨基-β-酮酸酯(β-含氧二肽)的合成研究

对α-氨基-β-酮酸酯(β-含氧二肽)的合成进行了探讨.以Boc保护的(L)-缬氨酸及(L)-异亮氨酸为原料,分别与(D,L)-苏氨酸甲酯盐酸盐进行偶合,再用Dess-Martin试剂(DMP)氧化,分别以48%和38%的总收率得到相应的氨基酮酸酯二肽化合物.     

新型脯氨酸类手性离子液体的合成

2-氨甲基吡啶分别与N-Boc-L-氨酸、N-Boc-L-羟脯氨酸及N-Boc-L-乙酰氧基脯氨酸反应合成了三个新的手性酰胺化合物(2a～2c);2a ～2c依次经季铵化、离子交换、脱Boc保护基制得新型脯氨酸类手性离子液体,其结构经UV-Vis,1H NMR和IR表征.     

7,8-二甲氧基-2,3,4,5-四氢-1H-苯并[c]氮杂卓盐酸盐的简便合成

苯并氮杂卓是一类重要的药物分子结构，以3,4-二甲氧基苯丙酸为原料，经氯化亚砜酯化，氨水氨解，酰胺还原成伯胺，氨基酰化保护，硫酸催化成环，脱乙酰基，氨基Boc保护、脱保护形成盐酸盐，经八步反应得到目标产物，其结构经¹H NMR，HR-MS(ESI)和元素分析表征。      

维格列汀的合成工艺改进

L-脯氨酸经(Boc)2O保护氨基后,在氯甲酸乙酯的作用下与氨水反应生成酰胺,再脱保护基制得L-脯氨酰胺盐酸盐(4);4与氯乙酰氯酰化得(S)-N-氯乙酰基-2-氨甲酰基吡咯烷(5);5经三氯氧磷脱水得(S)-N-氯乙酰基-2-氰基吡咯烷(6);6与3-氨基-1-金刚烷醇经亲核取代反应合成了维格列汀(1)粗品。粗品与盐酸成盐后再游离制得高纯度(99.7%)的1,总收率35.5%,其结构经1H NMR和ESI-MS确证。     

Boc-L-(苯丙)噻唑-4-甲酸甲酯的合成研究

本文分别以L-苯丙氨酸甲酯盐酸盐和叔丁氧羰基保护的L-苯丙氨酸为起始原料,经两种不同的合成路线,完成了Boc-L-(苯丙)噻唑-4-甲酸甲酯的合成。其中,第一条路线共五步反应,总收率18%;第二条路线共四步反应,总收率22%,两条路线所涉及的官能团转换和反应有:氨基Boc保护、酯基还原、羟基Parikh-Doering氧化,MnO_2氧化,N-甲氧基-N-甲酰胺化。     

手性双哌啶酰胺的合成

N-烷基双哌啶与Boc保护的L-氨基酸反应,再经三氟乙酸脱Boc保护合成了两个新型手性双哌啶-α-氨基酰胺——3-[(2′S,4′R)-4′-乙酰氧基-2′-吡咯烷基]甲酰基-7-正丙基-3,7-二氮杂双环[3.3.1]壬烷和3-[(2′s)-2′-吡咯烷基)甲酰基-7-异丙基-3,7-二氮杂双环[3.3.1]壬烷,其...     

3-聚苯乙烯磺酰基丙醇的制备及其在固相有机合成中的应用

本文采用聚苯乙烯亚磺酸钠树脂1与3-氯丙醇在碘化四正丁胺和碘化钾的存在下反应制备了3-聚苯乙烯磺酰基丙醇树脂2.以该树脂为载体固载了Boc保护的L-丙氨酸,再经封羟基、脱保护、中和,与异氰酸苯酯反应制得聚合物支载的脲6.脲树脂6在酸性或强碱条件下解脱得到取代的海因化合物,在弱碱条件下解脱得到取代的脲化合物.     

氨基磺酸催化剂在有机合成中的应用

综述了近年来氨基磺酸作为一种绿色催化剂在有机合成中的应用,主要包括酯化与酯交换、基团保护、氮杂Diels-Alder、重排、取代及缩合等反应。参考文献58篇。     

Preparation of polysiloxanes from silicic acid. V. Condensation of silicic acid butyl esters and formation of silica fiber from the ester solutions

The condensation of silicic acid butyl esters was investigated by gel permeation chromatographic (GPC) analysis. The results revealed that the condensation was greatly dependent on a degree of esterification of the esters. The ester with the lowest degree of esterification underwent condensation to form a highly polymerized ester. It was found that fibers could be drawn from the ester solution before gelation.     

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%.     

新型查尔酮类化合物的合成及其生物活性研究

以3,5-二羟基苯甲酸为原料, 分别经酯化、甲氧甲基保护或甲基化、酰肼化、氧化、醛酮缩合、脱保护基、O-法呢基化或O-异戊烯基化等步骤, 以5.6%～46%的总收率合成了8个未见文献报道的查尔酮类化合物1a～1h, 产物通过¹H NMR, ¹³C NMR, IR, MS进行了结构确证. 对所合成的目标化合物在3个标准活性筛选模型中进行了生物活性试验, 结果表明化合物1b在组织蛋白酶B (CAT-B)模型、化合物1e在细胞分离周期基因25表达的蛋白磷酸酶(CDC25)模型中表现出良好的活性.     

丙嗪的合成研究

口恶丙嗪的合成研究杨艺虹贺小平黎华＊（武汉化工学院制药教研室，武汉，４３００７４）恶丙嗪的合成研究杨艺虹贺小平黎华＊（武汉化工学院制药教研室，武汉，４３００７４）关键词口恶丙嗪安息香缩合合成口恶丙嗪（Ｏｘａｐｒｏｚｉｎｅ，１）为一新型口服长效芳基丙酸...     

Formation of C-C and C-O bonds and oxygen removal in reactions of alkanediols, alkanols, and alkanals on copper catalysts

This study reports evidence for catalytic deoxygenation of alkanols, alkanals, and alkanediols on dispersed Cu clusters with minimal use of external H(2) and with the concurrent formation of new C-C and C-O bonds. These catalysts selectively remove O-atoms from these oxygenates as CO or CO(2) through decarbonylation or decarboxylation routes, respectively, that use C-atoms present within reactants or as H(2)O using H(2) added or formed in situ from CO/H(2)O mixtures via water-gas shift. Cu catalysts fully convert 1,3-propanediol to equilibrated propanol-propanal intermediates that subsequently form larger oxygenates via aldol-type condensation and esterification routes without detectable involvement of the oxide supports. Propanal-propanol-H(2) equilibration is mediated by their chemisorption and interconversion at surfaces via C-H and O-H activation and propoxide intermediates. The kinetic effects of H(2), propanal, and propanol pressures on turnover rates, taken together with measured selectivities and the established chemical events for base-catalyzed condensation and esterification reactions, indicate that both reactions involve kinetically relevant bimolecular steps in which propoxide species, acting as the base, abstract the α-hydrogen in adsorbed propanal (condensation) or attack the electrophilic C-atom at its carbonyl group (esterification). These weakly held basic alkoxides render Cu surfaces able to mediate C-C and C-O formation reactions typically catalyzed by basic sites inherent in the catalyst, instead of provided by coadsorbed organic moieties. Turnover rates for condensation and esterification reactions decrease with increasing Cu dispersion, because low-coordination corner and edge atoms prevalent on small clusters stabilize adsorbed intermediates and increase the activation barriers for the bimolecular kinetically relevant steps required for both reactions.     

Synthesis and Antibacterial Activity of Benzenesulfonylhydrazone Derivatives of Methyl Dehydroabietate

Russian Journal of General Chemistry - Six benzenesulfonylhydrazone derivatives of methyl dehydroabietate are synthesized via esterification, benzylic oxidation, condensation with hydrazine...     

CARBODIIMIDE-MEDIATED ESTERIFICATIONS AND CONDENSATIONS OF PHOSPHORIC ACIDS DISSOLVED IN VARIOUS ALCOHOLS

Abstract

Carbodiimide-mediated phosphorylations carried out with ortho-, pyro-, trimeta-, tetrameta-, and long-chain polyphosphoric acids dissolved in various alcohols, with and without an excess of tri-n-butylamine at 27° were found to consist of complicated reaction sequences involving various phosphoric acids, then esters and complexes formed between the carbodiimide and these acids or esters. In the case of the condensation of orthophosphoric acid, the process of stepwise esterification is seen to compete with the process of condensation to form condensed phosphoric acids and their esters. In general, esterification as opposed to condensation is promoted by (a) increased acidity, (b) smaller size, and (c) increased concentration of the alcohol, as well as by (d) increased concentration of dissociable protons in the solution. ³¹P chemical-shift data are given for ortho, chain, and ring phosphoric acids and their esters dissolved in the corresponding alcohol. Typical kinetic curves and the distribution of products obtained upon the cessation of condensation are also presented.     

制备溴螨酯的新工艺

以对溴甲苯为原料,用Mn2O3直接氧化合成了对溴苯甲醛,再经缩合、重排、酯化等步骤制得低毒杀螨剂溴螨酯.     

Syntheses of Nucleoside Derivatives Containing Fmoc- or Trityl-protected Amino Acids

Facile direct esterification reactions between 2‘, 3‘-O-isopropylidene-nucleosides and Fmoc- or trityl-protected amino acids via N, N-dicyclohexyl-carbodiimide(DCC) mediated condensation are described. These reactions offer a mild and convenient method to synthesize aminoacylated nucleoside derivatives.