1,3,5-三[(4’-乙炔基苯基)乙炔基]苯的合成

设计了多种合成路线制备芳香炔基树枝状化合物中间体1,3,5-三[(4’-乙炔基苯基)乙炔基]苯,通过一系列的合成路线和反应条件的对比,发现多官能团的端基炔化合物与芳基溴化合物之间发生多重Sonogashira反应时,常会生成不同取代程度的极性相似化合物,因而难以分离.采用多官能团的端基炔化合物与芳基碘化合物反应可以避免这种情况.最终确定以1,3,5-三溴苯和2-甲基-3-丁炔-2-醇为原料,制得中间产物1,3,5-三乙炔基苯;再以对碘苯胺和三甲基硅乙炔为原料,经重氮化化、卤代反应制得4-三甲基硅乙炔基碘苯;后者与1,3,5-三乙炔苯经Sonogashira反应、裂解去保护反应,制得化合物1,3,5-三[(4’-乙炔基苯基)乙炔基]苯.用1H NMR,13C NMR,元素分析等表征手段确认了中间体及最终产物的结构.     

选择性HDAC6抑制剂4-（（2,4-二氧基-3-苯乙基-3,4-二氢喹唑啉-1（2H）-基）-甲基）-N-羟基苯甲酰胺的合成

以靛红酸酐（2）为起始原料,经氮上烷基化、开环、关环以及酯的氨解生成异羟肟酸等多步简单反应合成了目标化合物选择性HDAC6抑制剂4-（（2,4-二氧基-3-苯乙基-3,4-二氢喹唑啉-1（2H）-基）-甲基）-N-羟基苯甲酰胺(1)。产物结构经¹H NMR、 ¹³C NMR 以及MS 确证。新的合成路线具有反应条件温和、后处理简单等优点，总收率83.8%。      

(2S,5S)-1-氮-3-氧-2,4,4-三苯基二环[3.3.0]辛烷衍生物的合成及表征

从不对称催化反应问世以来,人们一直在寻找高效、廉价、易制备的手性催化剂。Himto Nakano等人用(S)-二苯基脯胺醇和2-二苯膦基苯甲醛合成了手性化合物(2S,5S)-1-氮-3-氧-2-二苯膦基苯-4,4-二苯基二环[3．3．0]辛烷,并与钯络合来催化不对称反应。     

4-(N-乙基-3-甲基苯胺基）丁酸甲酯的合成

以γ-丁内酯为起始原料,经开环氯化和醇解反应合成4-氯丁酸甲酯（2）; 2与N-乙基间甲苯胺经亲核取代反应合成了4-(N-乙基-3-甲基苯胺基）丁酸甲酯,纯度97.5%,总收率75.3%,其结构经¹H NMR确证。     

6-(3-氨基苯基)-4, 5-二氢哒嗪-3(2H)-酮的合成

以苯、丁二酸酐为原料,经傅克酰基化,硝化,与水合肼反应三步反应合成6-(3-氨基苯基)-4,5-二氢哒嗪-3(2H)-酮(1),总收率为58.3%。由3-(3-硝基苯甲酰基)丙酸(3)合成化合物1的过程中,在雷尼镍(Raney Ni)的催化下与水合肼反应,一步完成了苯环上硝基的还原和成环。重点考察了该步反应的物料配比、反应时间对产率的影响。结果表明,水合肼与化合物3的摩尔比11.7∶1,回流反应4 h,产率为82.7%。     

带有不同端炔保护基团的新型苯乙炔树枝状化合物的合成

以1,3,5-三溴苯为原料,通过Sonogashira反应,设计并合成了两种带有不同端炔保护基团的1,3,5-取代的苯乙炔树枝状化合物:1,3,5-三[3-(3-甲基-3-羟基-1-丁炔基)-5-(三异丙基硅乙炔基)苯基乙炔基]苯(B1)和1,3,5-三[3-(三甲基硅乙炔基)-5-(三异丙基硅乙炔基)苯基乙炔基]苯(B2),并对合成路线的选择进行了比较和讨论.用1H NMR,13C NMR,质谱,元素分析等表征手段确认了中间体及最终产物的结构.这两种苯乙炔树枝状化合物各自带有两类不同的周边端炔保护基团,可根据其脱保护条件的不同引入不同的周边功能基团.     

经由三丁基锡化氢、炔基砜和炔基溴的锡氢化-Stille串联反应“一锅”立体选择合成( Z)-2-砜基取代的1,3-烯炔

炔基砜和三丁基锡化氢在四(三苯基膦)钯催化下于苯中室温下进行锡氢化反应4 h,经溶剂转换成DMF后,再在CuI助催化剂存在下与炔基溴化物于室温进行Stille偶联反应,以良好产率且立体选择性地合成了( Z)-2-砜基取代的1,3-烯炔。该“一锅”合成法具有起始原料易得、反应条件温和、操作简便、钯催化剂利用率高和产率好等优势。     

具有除草活性的3-(嘧啶基-2)-1,3,4-噁二唑-2(3H)-酮衍生物的设计、 合成与定量构效关系的研究

设计合成了一系列未见文献报道的5-叔丁基-3-[4-取代-5-(氢)甲基嘧啶-2-基]-1,3,4-噁二唑-2(3H)-酮的衍生物, 其结构均经过1H NMR, IR和元素分析表征. 生测结果显示, 部分化合物表现出较好的除草活性. 定量的结构与活性关系研究表明, 它们的除草活性与取代基的立体效应参数和电性参数呈现很好的相关性, 相关系数r大于0.8. 当作用对象为油菜时, 化合物的活性可能主要与取代基R2的邻位立体效应参数Es和电性参数相关; 当作用对象为稗草时, 化合物的活性主要与取代基R2邻位立体效应参数Es和间位取代基电性参数相关.     

2,3-二氯-5,6-二氰基苯醌/H~+作用下4-苯亚甲基-3-异色酮的分子内氧化偶联反应

多甲氧基菲-9-甲酸及酯是合成娃儿藤生物碱及其类似物的关键中间体.以4-(3,4-二甲氧基苯亚甲基)-6,7-二甲氧基-3-异色酮(6)为底物,2,3-二氯-5,6-二氰基苯醌(DDQ)/CH3SO3H作为氧化体系,没有得到预期的多甲氧基菲-9-甲酸内酯(1),意外产物经核磁共振等确定为两个新的3-取代苯基香豆素2,3.进一步的实验研究显示:底物发生分子内脱氢偶联为香豆素2而非菲环化合物1,是因为异色酮6苯环A上2位取代基的存在所致,其内酯环开环化合物10以及2,3-二苯基丙烯酸(12)的对比实验印证了该取代基对脱氢偶联反应选择性的影响;异色酮6氧化偶联为香豆素2的反应机理可能为酸解开环以及途经自由基正离子的脱氢偶联,香豆素3为DDQ氧化2的前体化合物8所得.     

1-(2-羟基苯甲酰基)-3-甲基-4-取代苯腙基-吡唑啉酮及其中间体的合成、表征及抑菌活性

依据生物活性叠加原理,将邻羟苯基、吡唑啉酮、苯腙基团进行合理组合,构建并合成了2-取代苯腙基-3-(2-羟基苯甲酰腙基)-丁酸乙酯(3a～3f)和1-(2-羟基苯甲酰基)-3-甲基-4-取代苯腙基-吡唑啉酮(4a～4f)两类、共计12种化合物,其中8种化合物未见报道,12种化合物的抑菌活性均未见报道.以芳胺为原料,经重氮化、与乙酰乙酸乙酯反应,与水杨酰肼缩合制得3a～3f,3a～3f经分子内关环制得4a～4f,化合物的结构经IR,1HNMR,元素分析等证实.生物活性测试表明,质量浓度为0.01%时,化合物3b,3c对大肠杆菌的抑菌率高达100%,具有很强的抑菌活性;化合物3a～3f对白色念珠菌、金黄色葡萄球菌的抑菌率均达70%以上,具有较强的抑菌活性;化合物4a～4f对白色念珠菌、大肠杆菌的抑菌率均接近或达到100%,具有很强的抑菌活性,对金黄色葡萄球菌的抑菌率均达78%以上,具有较强抑菌活性;与3a～3f相比,形成吡唑啉酮环后的化合物4a～4f的抗菌活性更高.     

Total synthesis of (-)-senepodine G and (-)-cermizine C

An efficient, stereospecific synthesis of the alkaloids senepodine G (2) and cermizine C (1) has been completed using the BF3.Et2O-promoted stereospecific addition of Me2CuLi to alpha,beta-unsaturated lactam 6 to provide lactam 3, the addition of MeMgBr followed by HCl to convert 3 to senepodine G (2) (six steps, 40% overall yield), and the stereospecific NaBH4 reduction of 2 to give cermizine C (1) (seven steps, 40% overall yield).     

Stereoconvergent synthesis of N-Boc-(2R,3S)-3-hydroxy-2-phenylpiperidine

The stereoconvergent synthesis of N-Boc-(2R,3S)-3-hydroxy-2-phenylpiperidine from (R)-1-(2-((tert-butyldimethylsilyl)oxy)-1-phenylethyl)piperidin-2-one is described. The key steps involved are α-hydroxylation of quiral lactam with O₂, stereoconvergent reduction of (R)- or (S)-3-(benzyloxy)-piperidin-2-one with Red-Al® which afforded in both cases the trans-bicyclic oxazolidine in high stereoselectivity after chromatographic purification and a stereospecific Grignard addition to chiral bicyclic oxazolidine.     

Total synthesis of an immunosuppressive glycolipid, (2S,3S,4R)-1-O- (alpha-d-galactosyl)-2- tetracosanoylamino-1,3,4-nonanetriol

[reaction: see text] A practical and efficient total synthesis of (2S,3S,4R)-1-O-(alpha-d-galactosyl)-2-tetracosanoylamino-1,3,4-nonanetriol, OCH 1b, a potential therapeutic candidate for Th1-mediated autoimmune diseases, is described. The synthesis incorporates direct alkylation onto epoxide 5 and stereospecific halide ion catalyzed alpha-glycosidation reaction. A key intermediate 10 was obtained in only eight steps and 37% overall yield from commercially available d-arabitol 2, and the total synthesis of 1b was accomplished in 12 steps and 19% overall yield. This method will enable the synthesis of a variety of phytosphingolipids, especially that with the shorter sphingosine side chain than 1a, in a highly stereoselective manner.     

Modified synthesis of methyl (1R,2R,3E,5R)-3-(hydroxyimino)-5-methyl-2-(1-methylethyl)-cyclohexanecarboxylate from (R)-4-menthen-3-one

A modified stereospecific synthesis of potentially biologically and pharmacologically active methyl (1R,2R,3E,5R)-3-(hydroxyimino)-5-methyl-2-(1-methylethyl)cyclohexanecarboxylate from (R)-4-menthen-3-one was developed using sequential 1,4-conjugate addition of Norman reagent catalyzed by CuI?CBF₃?Et₂O?CCuCl₂ and ozonolysis?Creduction of the intermediate (R,R,R)-vinylmenthone by hydroxylamine hydrochloridein MeOH.     

Functionalization of Testosterone at Position 7α and Synthesis of 7α-(3-Methoxypropyl)-4-androsten-17β-ol-3-one

An efficient transformation of the terminal alkene function of 7α-allyltestosterone is reported along with the stereospecific synthesis of 7α-(3-methoxypropyl)-4-androsten-17β-ol-3-one.     

Efficient stereospecific synthesis of (S,S)-3-methoxy-4-methylaminopyrrolidine

Efficient stereospecific synthesis of (S,S)-3-methoxy-4-methylaminopyrrolidine, an important intermediate for a novel quinolone antitumor agent AG-7352 is presented. Starting from either d- or l-tartaric acid, a stereospecific synthesis of the chiral pyrrolidine was achieved via two S_N2 displacement reactions. From the results of this synthetic study, the absolute structure of AG-7352 was chemically determined.     

(1S)-1-[(4R)-2,2-dimethyl-1,3-dioxolan+-4-yl][-2-hydroxyethylamm onium benzoate, a versatile building block for chiral 2-aminoalkanols: concise synthesis and application to nelfinavir, a potent HIV-protease inhibitor

A concise synthesis of a versatile chiral C4 building block for 2-aminoalkanols, (1S)-1-[(4R)-2,2-dimethyl-1,3-dioxolan-4-yl]-2-hydroxyethylammo nium benzoate (1a), was described. 1 (1a and its enantiomer 1b) acted as four stereoisomers of optically active 2-amino-1,3,4-butanetriol. The versatility of 1 was demonstrated by its application to the practical synthesis of nelfinavir (2), a potent HIV-protease inhibitor, as well as by the stereospecific synthesis of three diastereomers of 2.     

Stereospezifität der neuroleptischen Wirkung und Chiralität von (+)-3-{2-[4-(8-Fluor-2-methyl-10,11-dihydrodibenzo[b,f]thiepin-10-yl)-1-piperazinyl]-äthyl}-2-oxazolidinon (16). 4. Mitteilung über tricyclische Antidepressiva und Neuroleptica

Stereospecifity of the neuroleptic activity and chirality of (+)-3-{2-[4-(8-fluoro-2-methyl-10, 11-dihydrodibenzo[b,f]thiepin-10-yl)-1-piperazinyl]ethyl}-2-oxazolidinone (16). The synthesis and stereospecific neuroleptic action in animals of the (+)-enantiomer of 3-{2-[4-(8-fluoro-2-methyl-10,11-dihydrodibenzo [b,f]thiepin-10-yl)-1-piperazinyl]ethyl}-2-oxazolidinone ( 16 ) are briefly described. The (10S)-configuration of this compound was determined by X-ray diffraction.     

A Stereospecific Synthesis of Cis-3-Substituted-2, 2-Dimethylcyclopropane-L-Carboxylates

A stereospecific synthesis of cis-3-substituted-2, 2-dimethylcyclopropane-1-carboxylates based on the cyclization of 5-bromolactone 2 to give bicyclic lactone 3 is described.     

A Total Synthesis of Aphidicolin: Stereospecific Synthesis of (±)-3α, 18-Dihydoxy-17-Noraphidicolan-16-one

A simple, efficient, and stereospecific total synthesis of (±)-3α, 18-dihydroxy-17-noraphidicolan-16-one (2) , by solvolytic rearrangement of the endo-bicyclo-[2.2.2]oct-5-en-2-yl methanesulfonate 16 , is described. Since aphidicolin (1) has already been obtained from 2 , the preparation of the latter formally constitutes a new total synthesis of 1 .