新型C_2对称的手性双噁唑啉的合成及与钛催化二乙基锌对醛的不对称加成反应

合成了 6个具有C2 对称性的类卟啉手性双唑啉配体 ,将这些化合物与Ti(OPr i) 4 配位应用于二乙基锌对芳香醛的不对称加成反应 ,获得了较高的化学产率和中等程度的ee值 ( 5 5 % ) .     

迈克尔加成法合成乙二胺枝状化合物

以乙二胺和丙烯酸异辛酯为原料,甲醇为溶剂,在无催化剂条件下,经迈克尔加成反应合成了低代的树枝状化合物.探讨了反应条件对产率的影响,发现适宜的条件为:n(乙二胺)∶n(丙烯酸异辛酯)=1∶5.0~6.5,反应温度为5~10℃,反应时间为48 h左右,产率可达55%.     

多功能光学活性丁二醇衍生物的合成和结构

通过新的合成策略,以手性合成子3和具有生物活性的有机碱类化合物4为反应底物,利用Michael不对称加成反应,合成得到光学纯的5-(R)-［(1R,2S,5R)-(-)-氧基］-4-(R)-(杂环碱基)-2(5H)-呋喃酮(5). 加成物5通过还原反应得到了多功能光学活性的二醇类化合物6,产率为42%~82%,e.e.≥98%. 化合物6的化学结构得到了确认,其立体化学结构和绝对构型经X射线晶体学测定得到了确定.     

3,5-二(2-吡啶基)吡唑的合成方法改进

以2-吡啶甲酸为原料,经酯化、缩合、加成合成了平面四齿双核配体3,5-二(2-吡啶基)吡唑。改进合成方法使加成反应的产率由原来的66%提高到98%。     

手性氨基醇的合成及其在二乙基锌与芳香醛的不对称加成反应中的应用

以天然氨基酸为手性源,合成了3个新的三齿手性氨基醇配体(1a～1c),其结构经1H NMR, IR和元素分析表征.将1用于催化二乙基锌与芳香醛的不对称加成反应,得到(R)-二级醇,产率96.7%, e.e.74.3%.     

(硫杂)杯[4]芳烃缩氨基(硫)脲(桥联)衍生物的合成

对叔丁基(硫杂)杯[4]芳烃-1,3-二醛基衍生物4a和4b与苯基氨基硫脲进行“1＋2”缩合反应, 合成了杯[4]芳烃缩氨基硫脲衍生物5a和5b, 产率为84%和85%. 化合物4a和4b与1,6-己基双氨基脲发生“1＋1”缩合反应, 合成了杯[4]芳烃双缩氨基脲桥联衍生物6a和6b, 产率为83%和80%. 新化合物的结构与构象经元素分析、质谱、核磁共振谱等表征证实.     

手性β-氨基醇的合成及其催化二乙基锌与醛的不对称加成反应

以烯烃为原料通过Sharpless不对称双羟化等多步反应合成7种手性β-氨基醇, 并将该类化合物用于催化二乙基锌和醛的不对称加成反应. 分别考察了影响对映选择性的催化剂结构、催化剂用量、溶剂、反应温度等各种因素. 当催化剂用量为5%、甲苯溶剂、在－10 ℃下、以(1S,2R)-(＋)-2-氨基-1,2-二苯基乙醇(1b)作催化剂时, 所得仲醇的对映体过量最高为85% ee, 产率高达100%.     

手性的H‘4-NOBIN衍生物在不对称加成和取代反应中的应用

以手性 H’4-NOBIN为原料合成了新型手性氨基酚2和N,P配体5, 并将化合物2应用于催化二乙基锌对醛的不对称加成反应, 产率达90%, 对映体过量最高为45.9% ee. 化合物5用于钯催化的1,3-二苯基-2-烯丙基乙酸酯的不对称烯丙基烷基化反应, 产率为89%, 对映体过量最高为81.6% ee. 结果表明氨基酚2手性诱导作用弱于未氢化的NOBIN, 但却高于其八氢衍生物, 而N,P配体5给出相反的结果.     

手性联二萘酚衍生物催化芳香醛的不对称炔基锌加成反应

以手性联二萘酚为原料,合成了3,3’位取代的手性联二萘酚衍生物,研究了在该衍生物配体、二乙基锌和三乙胺条件下的苯乙炔对芳香醛的不对称加成反应,得到较好产率(43%～71%)的炔丙醇,ee值最高为68%。     

5-芳基四氮唑衍生物的高效合成方法与酯基的伴生降解

以氯化铟为催化剂,通过芳基腈和叠氮化钠的[3+2]环加成反应合成了一系列5-芳基四氮唑,含各种官能团的底物都可以获得高产率.此合成方法还对酯的分解有催化效果,可以在合成四氮唑的同时对酯进行脱保护获得羧酸和醇.     

Enantioselective synthesis of indolizidine alkaloid trans-209D

(S)-N-Boc-baikiain, readily accessible from enantiomerically enriched 2,3-epoxy-5-hexen-1-ol 4 (prepared by Sharpless asymmetric epoxidation), was used as the starting material in the synthesis of indolizidine alkaloid trans-209D , which was obtained in 13 steps and 14% yield from 1 (5% from 4).     

Total synthesis of cochleamycin A

[reaction: see text] Cochleamycin A (1) was synthesized in 2.4% overall yield via a 23-step linear sequence starting from 3-butene-1-ol. Key features of the synthesis include the synthesis of (Z)-1,3-diene 21 via a Stille coupling of 4 and 5 and a transannular Diels-Alder reaction of macrocycle 26 to provide the complete carbon skeleton of 1.     

Isolation,Structure Determination and Synthesis of New Acetylenic Steroids from the Sponge Calyx nicaaensis

Two acetylenic steroids, cholest-5-en-23-yn-3β-ol ( 5 ) and 26,27-dinorcholest-5-en-23-yn-3β-ol ( 3 ), and another unsaturated steroidalcohol, stigmasta-5,23-dien-3β-ol ( 7 ), were isolated from the sponge Calyx nicaaensis. The structures of these two acetylenic steroids were established by synthesis. Several attempts to synthesize the marine steroids alcohol calysterol ( 1 ), with a cyclopropene-containing side chain, starting from cholest-5-en-23-yn-3β-ol are also recorded. Addition of ethyl-diazo-acetate to the triple bond was performed, but the reduction to the methyl derivative yielded decomposition products.     

Ir-catalyzed allylic amination/ring-closing metathesis: a new route to enantioselective synthesis of cyclic beta-amino alcohol derivatives

Ir-catalyzed allylic aminations of (E)-4-benzyloxy-2-butenyl methyl carbonate with benzylamine using Feringa's (Sa,Sc,Sc)-phosphoramidite as a chiral ligand afforded linear-aminated achiral product N,O-dibenzyl-4-amino-2-buten-1-ol regioselectively (linear/branched = >99/1), whereas the (E)-5-benzyloxy-2-pentenyl methyl carbonate showed completely opposite regioselectivity (linear/branched = >1/99) and afforded the optically active (3R)-N,O-dibenzylated 3-amino-1-penten-5-ol with very high enantioselectivity (96% ee), which was used as a key intermediate for the effective synthesis of various cyclic beta-amino alcohol derivatives through ring-closing metathesis in high yields.     

3-甲基-5-苯砜基-3E-戊烯-1-醇的立体专一性合成

3-甲基-5-苯砜基-3E-戊烯-1-醇(1)是合成某些萜类化合物的重要中间体.它具有反式烯丙基苯砜基双键.Julia等曾报道用含砜基的环丙基醇的开环重排反应来实现这类化合物的立体选择性合成,但其开环前体不易得到.本文以4-羟基-2-丁酮(2)为起始原料,经4步反应立体专一性地合成了标题化合物1.合成路线短、操作简便、易于大量制备.合成路线用方程式表示如下:     

Photocatalytic Synthesis of Gold Nanoparticles Using Preyssler Acid and Their Photocatalytic Activity

Preyssler acid H14[NaP5W30O110] was used as reducing agent and stabilizer for the synthesis of gold nanoparticles by photolysis of Au(III)/Preyssler acid/propan-2-ol solution.Preyssler acid plays both the role of transferring electrons from propan-2-ol to Au(III) and stabilizing the nanoparticles.Propan-2-ol was used as sacrificial reagent for the photoformation of reduced Preyssler acid.Gold nanoparticles (Au NPs) were characterized by UV-Vis spectroscopy,transmission electron microscopy (TEM),and particle size distribution (PSD) measurements.The synthesized Au NPs had a uniform hexagonal morphology and their size was about 17 nm.The catalytic performance of these NPs for photodegradation of methyl orange (MeO) was investigated in aqueous solution.UV-Vis studies showed that Au NPs can catalyze photodegradation of this azo dye.The pseudo-first-order rate constants were also calculated for this reaction.     

用硝酸-亚硝酸钠双键异构化反应制备昆虫性信息素或其合成中间体

天然昆虫性信息素常是一定比例的两个或几个顺、反异构体的混合物。合成顺式烯烃已有许多有效的方法,如用Lindlar或P-2Ni催化剂氢化炔键,这些方法不仅产率高而且产物的纯度也高。本文报道应用HNO_3-NaN_2异构化双键的方法,使易得的顺式烯烃转化为顺、反异构体的混合物,并研究了温度对反应产物顺、反比例的影响。我们选用顺-3-辛烯醇-1(la)及其乙酸酯(lb),顺-9-十四烯醇-1-乙酸酯(2)和顺-11-十四烯醇-1-乙酸酯(3)进行实验。它们在各种温度下用HNO_3-NaNO_2转化可得不同比例的顺、反混合物(表1)。     

Optimized synthesis of new LE404-derived azecine-prodrugs

Dibenzoazecines represent a class of high-affinity dopamine and serotonin receptor antagonists. The former synthesis of the lead structure 7-methyl-5,6,7,8,9,14-hexahydrodibenzo[d,g]azecin-3-ol (LE404) has been 5 steps with a total yield of 13%. The present work enabled the synthesis of LE404 with a much higher yield. Based on this research, further azecin derivatives were synthesized with the aim to improve pharmacokinetic parameters.     

Identification of phytobioconstituents present in Simmondsia chinensis L. seeds extract by GC-MS analysis

Simmondsia chinensis L. commonly called as Jojoba and belongs to family Simmondsiaceae. It has shown positive pharmacological activities of these compounds which include antidiabetic, antirheumatic, anthelminthic, antipsoriatic, antioxidant, antiepileptic, antigonorrheal, analgesic, anti-inflammatory, and pesticidal activity of jojoba. The multifaceted action of numerous bioactives existing in the seed extract with therapeutic activity have attracted great research interest by pharmaceutical industries. n-hexane extract of Simmondsia chinensis L. (SC) Seeds was analysed by gas chromatography-mass spectroscopy for identification and characterization of phytobioconstituents and its therapeutic claim by traditional system. The major compounds discovered in SC seeds extract are cis-9-octadecen-1-ol (24.85%), 9-octadecen-1-ol, (Z)- (18.24%), Stigmast-5-en-3-ol (14.10%), Ergost-5-en-3-ol, (3-β)-ol (5.26%), (Z)-14-tricosenyl formate (5.24%), Thiositosteroldisulfide (3.64%), Silane, Dimethyl (dimethylpentyloxysilyloxy) tetradecyloxy- (3.41%), Ergost-5-ene, 3-methoxy-, (3β,24R)- (2.55%), Ergosta-5,22-dien-3-ol (2.22%), 1,19-eicosadiene (2.17%), Pentacosane (2.02%), Stigmasta-5,22-dien-3-ol (1.64%), 1,19-eicosadiene (1.57%), 9-octadecen-1-ol, (Z)- (1.46%), 9,19-cyclo-9β-lanostan-3β-ol, 24-methylene- (1.14%), (9Z)-9-octadecenyl palmitate (1.50%), Hexadecanoic acid, 9-octadecenyl ester, (Z) (1.37%), 9Z)-9-octadecenyl (9Z)-9-hexadecenoate (1.01%). The hexane extract of Simmondsia chinensis seeds comprises various polar and nonpolar phytobioconstituents. These compounds were established qualitatively via GC-MS evaluation. GC-MS reports will be promising in pharmaceutical sector in identification of variety of Phytobioconstituents in distinct plant extracts, polyherbal extract and the standardization of particular plant materials.     

Novel chemoenzymatic strategy for the synthesis of enantiomerically pure secondary alcohols with sterically similar substituents

A novel chemoenzymatic strategy for the synthesis of enantiomerically pure secondary alcohols with sterically similar substituents is described. The key step is the kinetic lipase-catalyzed resolution of racemic mixtures of substituted propargylic alcohols. The efficiency of this new approach was tested in the preparation of the corresponding enantiomers of 1,11-hexadecandiol derivatives ((R)-5 and (S)-5). Two strategies were tested. In the first one, the racemic intermediate 1-octyn-3-ol (1) was resolved enzymatically and then elongated with 1-bromo-9,11-dioxadodecane. Alternatively, the racemic 1 can be elongated to the corresponding racemic 17,19-dioxa-7-eicosyn-6-ol (3) first and then resolved biocatalytically. Twelve commercially available lipases were screened for the kinetic resolution of these intermediates. Among them, Candida antarctica lipase (CAL-B) and Humicola lanuginosa lipase (HLL) were the best biocatalysts for the resolution of 1 (S enantiomer 90% ee, E = 35), and 3 (R enantiomer 90% ee, E = 34), respectively.