光学活性3-(1′-羟基乙基)-4-乙酰氧基-β-内酰胺的立体选择性合成

(1′R,3R,4R)-N-取代-3-(1′-羟基乙基)-4-乙酰氧基-β-内酰胺(3)是合成青霉烯和碳青霉烯类β-内酰胺抗生素的关键中间体.以廉价的L-抗坏血酸为原料,制得S-缩异丙氧叉甘油醛(5),与胺反应定量转变成相应的手性亚胺(6a～6d),6与双烯酮[2+2]环加成反应,高立体选择性地合成3(S)-乙酰基-β-内酰胺(Sa～8d),其非对映体过量由类似反应的80％提高到接近100％.8a经四步反应得到目标化合物3a.     

8(或6)-氯-7-羟基-4-甲基香豆素及其衍生物的合成

以2(或4)-氯间苯二酚和乙酰乙酸乙酯为原料,通过Pechmann缩合反应,合成了新的8(或6)-氯-7-羟基-4-甲基香豆素(1a或1b); 1经硫酸二甲酯甲基化得2a或2b; 以四正丁基溴化铵作相转移催化剂,1经Williamson反应合成了6个新的氯代香豆素衍生物(3a～6a, 3b, 4b),产率66%～92%.1～6的结构经1H NMR, IR和GC-MS表征.     

N-(5-对-氯苯氧甲基-1,3,4-噻二唑-2-基)-S-(4-苯基-5-苯氧甲基-1,2,4-三唑-3-基)乙酰胺的合成与表征

取代苯氧乙酰肼(1a～1c)与异硫氰酸芳基酯(2a～2d)反应得到酰基硫脲类化合物(3a～3l),经碱合环得到4-苯基-5-苯氧甲基-1,2,4-三唑-3-硫酮(4a～4l),然后再与N-(5-对氯苯氧甲基-1,3,4-噻二唑-2-基)氯乙酰胺(6)反应合成了化合物N-(5-对氯苯氧甲基-1,3,4-噻二唑-2-基)-S-(4-苯基-5-苯氧甲基-1,2,4-三唑-3-基)乙酰胺(7a～7l)。所有化合物结构经元素分析、IR、1HNMR和MS确证。测定了化合物4e的晶体结构,其属于三斜晶系,P-1空间群,晶胞参数a=7.123(4),b=9.786(5),c=11.543(6),α=70.846(7)°,β=80.089(9)°,γ=89.922(11)°,V=747.5(7)3,Dc=1.345g/cm3,Z=2,F(000)=310,μ=0.218mm-1,R=0.0913,wR=0.2622     

(R)-N-(β-三氯锗取代丙酰基)TTCA酯的合成及其倍半氧化物

β-三氯锗取代丙酰氯1a～1c与(R)TTCA酯反应, 得到光学活性的(R)-N-(β-三氯锗取代丙酰基)TTCA酯3a～3d([α]D^2^0-86.00～-94.35ⅲ)及光学活性的β-三氯锗取代丙酰氯2a～2d。化合物3a～3d经水解得到(R)-N-(β-取代丙酰基)TTCA酯基锗倍半氧化物4a～4d, [α]D^2^0-44.48～-77.00ⅲ。用半经验量子化学MNDO方法研究了反应物和产物最优构型的电子结构及反应的焓变。     

新型含2-苯基-1,2,3-三唑基的1,5-苯并硫氮杂革及其β-内酰胺衍生物的合成

α,β-不饱和酮(1a～1e)与邻氨基苯硫酚反应,得到含2-苯基-1,2,3-三唑基的1,5-苯并硫氮杂革(2a～2e),然后以其为原料与烯酮"现场"进行[2+2]环加成,合成出一系列含2-苯基-1,2,3-三唑基的β-内酰胺并合的1,5-苯并硫氮杂革衍生物(3a～3j).产物经1H NMR,IR,元素分析及MS加以确证.     

α-(α’-甲基-卤代苄氧基)-β-(1-咪唑基)-2,4-二氯乙苯硝酸盐的合成与结构表征

先以间二氯苯、氯乙酰氯和咪唑为原料合成β-( 1 -咪唑基 ) -2 ,4 -二氯 -α-苯乙醇 ( ) ,再以二卤苯为原料合成α-氯 -卤代乙苯 ( a～ d) ,然后 , 分别与 a～ d反应 ,生成α-(α -甲基 -卤代苄氧基 ) -β-( 1 -咪唑基 ) -2 ,4 -二氯乙苯硝酸盐 4个新化合物 ,产率分别为 66.8% ,78.5% ,76.8%和 81 .2 % ,新化合物的结构经元素分析 ,IR和 1H NMR表征     

6-(4-取代苯乙烯基)-8-(4-取代苯基)-10,10-二甲基-10H-吡啶并[1,2-a]吲哚盐的合成

通过2,3,3-三甲基-3H-吲哚高氯酸盐与取代双亚苄基丙酮在异戊醇中的反应,合成五种新的6-(4-取代苯乙烯基)-8-(4-取代苯基)-10,10-二甲基-10H-吡啶并[1,2-a]吲哚盐[R=H(3a),Cl(3b),Br(3c),MeO(3d),Me_2N(3e)]。     

三有机锡(4R)-3-[[(2S)-5-氧-2-吡咯烷基]羰基]-4-噻唑烷甲酸酯的合成、结构和体外抗癌活性

利用三有机锡氢氧化物和手性配体(4R)-3-[[(2S)-5-氧-2-吡咯烷基]羰基]-4-噻唑烷甲酸(HL)反应合成了3个三有机锡(4R)-3-[[(2S)-5-氧-2-吡咯烷基]羰基]-4-噻唑烷甲酸酯R3SnL[1,R=c-C6H11(a),C6H5(b),C6H5C(CH3)2CH2(c)],通过元素分析、IR、1H NMR和X-射线单晶衍射表征了其结构。化合物1a属正交晶系,P212121空间群;化合物1b属单斜晶系,P21空间群。二者均为由羧基氧和内酰胺羰基氧桥联配位形成的右螺旋链状有机锡配位聚合物,锡原子具有五配位[SnC3O2]畸变三角双锥构型。化合物1a和1b对体外2种人癌细胞Colo205和Bcap37增殖均有强的抑制作用,其活性为1b1a。     

利用Reformatsky反应合成1-β-碳氢霉烯类抗生素中间体

以(2R)-3-[(3S,4R)-1-(叔丁基二甲基硅氧基)乙基]-4-乙酰氧基氮杂环丁-2-酮为母体,2-溴乙(丙)酸酯或2-溴丙酰胺为亲核试剂,通过Reformatsky反应合成了一系列新型的1-β-碳氢霉烯类抗生素中间体——3-{(2R)-2-[(3S,4R)-1-(叔丁基二甲基硅氧基)乙基]氮杂环丁-2-酮-4-基}乙(丙)酸酯(3a～3d)和3-{(2R)-2-[(3S,4R)-1-(叔丁基二甲基硅氧基)乙基]氮杂环丁-2-酮-4-基}-N,N-二取代丙酰胺(3e,3i和3k),其结构经1H NMR和13C NMR表征,其中3a～3e和3i未见文献报道。     

手性联萘基-2,2'-联吡啶及其衍生物的合成及其在不对称合成中的应用

利用Kröhnke方法,以芳基乙酮为原料一锅法简洁地合成了6-芳基-6'-溴-2,2'-联吡啶2b~2d。 通过(R)-3-(4,4,5,5-四甲基-1,3,2-二噁唑硼烷基)-2,2'-乙氧基-1,1'-联萘((R)-1)与6-溴-2,2'-联吡啶及其衍生物2a~2d的Suzuki偶联, 合成了4种手性6-[3-((R)-2,2'-二乙氧基-1,1'-联萘)基]-2,2'-联吡啶(R)-3a~3d。 将配体(R)-3a~3d应用于苯乙酮的不对称氢转移反应中,配体(R)-3a给出92%的转化率和4%的对映体过量(ee)值。     

Remote stereocontrol in reactions between 4- and 5-alkoxyalk-2-enylstannanes and 1-alkoxycarbonylimines and analogues: stereoselective approaches to novel α-amino acids

Reactions of the allyltin trichloride 45 generated from (4S)-4-benzyloxypent-2-enyl(tributyl)stannane 1 with imines prepared from glyoxylates proceed with useful levels of 1,5-stereocontrol in favour of (4E)-2,6-anti-2-(alkylamino)-6-benzyloxyhept-4-enoates 49. This stereoselectivity, controlled by the chirality of the stannane, dominates over any intrinsic stereochemical bias of the imine although a small amount of matching and mis-matching was observed. The allyltin trichloride 77 prepared from (4S)-4-(tert-butyldimethylsilyloxy)pent-2-enyl(tributyl)stannane 52 reacts with 1-alkoxycarbonylimines with the opposite 1,5-stereoselectivity to give the (4E)-2,6-syn-diastereoisomers 79. Matching and mismatching was more pronounced for tin(IV) chloride mediated reactions of (4R)-5-benzyloxy-4-methylpent-2-enyl(tributyl)stannane 80 with chiral 1-alkoxycarbonylimines but useful stereoselectivity in favour of (4E)-2,6-syn-2-alkyl- and arylthio-amino-7-benzyloxy-6-methylhept-4-enoates 177 was observed for reactions with achiral imines and similar, but reduced, stereoselectivity was observed for the 5-tert-butyldimethylsilyloxypentenylstannane 82. However, excellent 1,5-stereocontrol in favour of the (4E)-2,6-anti-isomers 179 was found using the 4,5-bis-alkoxypent-2-enylstannane 106. Modest (4E)-2,7-anti-stereoselectivity was observed in the analogous tin(IV) bromide mediated reactions of (S)-5-methoxy- and (S)-5-hydroxyhex-2-enyl(tributyl)stannanes (S)-123 and (S)-122 with achiral 1-alkoxycarbonylimines but in this series the intrinsic stereochemical bias of the imine controls the facial selectivity of reactions of chiral 1-alkoxycarbonylimines. Useful (4E)-2,6-anti-stereoselectivity was also observed in the tin(IV) chloride promoted reaction of the 4-benzyloxypent-2-enylstannane 1 with an oxime O-benzyl ether.     

有机锂试剂对二茂铁亚胺的不对称加成反应

研究了利用(－)-sparteine辅助的有机锂试剂对非手性二茂铁亚胺的对映选择性加成和对衍生于廉价的苯乙胺的手性二茂铁亚胺的非对映选择性加成反应. 对亚胺结构和实验条件对反应的影响进行了深入研究. 在有机锂试剂对非手性二茂铁亚胺的对映异构体选择性加成中得到了中等的对映选择性, 对衍生于(R)-苯乙胺的手性二茂铁亚胺的非对映选择性加成反应, 路易斯酸BF3•OEt2的添加对反应非常有利, 得到了非常好的非对映选择性.     

Asymmetric synthesis of aziridines by reduction of N-tert-butanesulfinyl alpha-chloro imines

Reduction of (RS)-N-tert-butanesulfinyl alpha-halo imines afforded chiral aziridines in good to excellent yields. Upon reduction of (RS)-N-tert-butanesulfinyl alpha-halo imines with NaBH4 in THF, in the presence of 10 equiv of MeOH, (RS,S)-beta-halo sulfinamides were formed in excellent yield (up to 98%) with very good stereoselectivity (>98:2). Simple treatment of the latter (RS,S)-beta-halo-tert-butanesulfinamides with KOH afforded the corresponding (RS,S)-N-(tert-butylsulfinyl)aziridines in quantitative yields. On the contrary, its epimer, (RS,R)-N-(tert-butylsulfinyl)aziridine was synthesized by switchover of the reducing agent from NaBH4 to LiBHEt3. (RS,R)-N-(tert-Butylsulfinyl)aziridines were synthesized in good yields (up to 85%) and diastereoselectivity (up to 92:8) by reduction of (RS)-N-tert-butanesulfinyl alpha-halo imines with LiBHEt3 in dry THF and subsequent treatment with KOH. All chiral aziridines were obtained as a single diastereomer after recrystallization (overall yield up to 91%) or after flash chromatography.     

C(2)-Symmetric bis-sulfoxide: A novel chiral auxiliary for asymmetric desymmetrization of cyclic meso-1,2-diols

A new heterocyclic compound, C(2)-symmetric bis-sulfoxide 1, has been found to be an efficient chiral auxiliary for asymmetric desymmetrization of cyclic meso-1,2-diols via diastereoselective acetal fission. Both (R,R)- and (S,S)-1 are readily synthesized with high optical purity via asymmetric oxidation of 1, 5-benzodithiepan-3-one (2). After acetalization of meso-1,2-diols 6a-e and a mono-TMS ether 6f with this chiral auxiliary 1, the resulting acetals 7a-f were subjected to base-promoted acetal fission upon treatment with potassium hexamethyldisilazide (KHMDS) followed by acetylation or benzylation to give the desymmetrized diol derivatives 8a-f with high diastereoselectivity. The chiral auxiliary 1 is readily removed by acid-promoted hydrolysis and can be recovered without a loss in enantiomeric excess.     

Direct synthesis of NNN-donor enantiopure scorpionate ligands by an efficient diastereoselective nucleophilic addition to imines

New enantiopure imines (1-9) with a chiral substrate to control the stereochemistry of a newly created stereogenic center have been synthesized by reaction of the commercially available (1R)-(-)-myrtenal and different primary amines. The diastereomerically enriched lithium-scorpionate compounds [Li(κ(3)-mobpza)(THF)] (10) (mobpza = N-p-methylphenyl-(1R and 1S)-1-[(1R)-6,6-dimethylbicyclo[3.1.1]-2-hepten-2-yl]-2,2-bis(3,5-dimethylpyrazol-1-yl)ethylamide), [Li(κ(3)-mobpza)(THF)] (11) (mobpza = N-p-methoxyphenyl-(1R and 1S)-1-[(1R)-6,6-dimethylbicyclo[3.1.1]-2-hepten-2-yl]-2,2-bis(3,5-dimethylpyrazol-1-yl)ethylamide), [Li(κ(3)-fbpza)(THF)] (12) (fbpza = N-p-fluorophenyl-(1R and 1S)-1-[(1R)-6,6-dimethylbicyclo[3.1.1]-2-hepten-2-yl]-2,2-bis(3,5-dimethylpyrazol-1-yl)ethylamide), and [Li(κ(3)-clbpza)(THF)] (13) (clbpza = N-p-chlorophenyl-(1R and 1S)-1-[(1R)-6,6-dimethylbicyclo[3.1.1]-2-hepten-2-yl]-2,2-bis(3,5-dimethylpyrazol-1-yl)ethylamide) were obtained by a diastereoselective 1,2-addition of an organolithium reagent to imines in good yield and with good diastereomeric excess (ca. 80%). The complexes [LiCl(κ(2)-R,R-fbpzaH)(THF)] (14) and [LiCl(κ(2)-R,R-clbpzaH)(THF)] (15) were obtained in enantiomerically pure form by the treatment of THF solutions of 12 or 13 with NH(4)Cl. The enantiomerically pure amines (R,R-mbpzaH) (16), (R,R-mobpzaH) (17), (R,R-fbpzaH) (18), and (R,R-clbpzaH) (19) were obtained by hydrolysis of the lithium-scorpionate compounds 10-13 with H(2)O. The lithium compound 12 was reacted with [TiCl(4)(THF)(2)] or [ZrCl(4)] to give the enantiopure complexes [MCl(3)(κ(3)-R,R-fbpza)] [M = Ti (20), Zr (21)]. The amine compound 18 reacted with [MX(4)] (M = Ti, X = O(i)Pr, OEt; M = Zr; X = NMe(2)) to give the complexes [MX(3)(κ(3)-R,R-fbpza)] (22-24). The reaction of Me(3)SiCl with [Zr(NMe(2))(3)(κ(3)-R,R-fbpza)] (24) in different molar ratios led to the halide-amide-containing complexes [ZrCl(NMe(2))(2)(κ(3)-R,R-fbpza)] (25) and [ZrCl(2)(NMe(2))(κ(3)-R,R-fbpza)] (26) and the halide complex 21. The isolation of only one of the three possible diastereoisomers of complexes 25 and 26 revealed that chiral induction from the ligand to the zirconium center took place. The structures of these compounds were elucidated by (1)H and (13)C{(1)H} NMR spectroscopy, and the X-ray crystal structures of 5, 12, 14, 15, and 24 were also established.     

Enantioselective total syntheses of the Ipecacuanha alkaloid emetine, the Alangium alkaloid tubulosine and a novel benzoquinolizidine alkaloid by using a domino process

The first enantioselective syntheses of the Ipecacuanha alkaloid emetine (1) and the Alangium alkaloid tubulosine (2) is described employing a domino Knoevenagel/hetero-Diels-Alder reaction and an enantioselective catalytic transfer hydrogenation of imines as key steps. Thus, hydrogenation of the imine 15 with the catalyst (R,R)-16 gives the tetrahydroisoquinoline 14 with 95 % ee which was transformed into the aldehyde (1S)-7. The three-component domino reaction of (1S)-7 with 6 and 8 led to 19, which in a second domino process was treated with K(2)CO(3) in methanol followed by a hydrogenation to give the benzoquinolizidine 4 together with the diastereomers 22 and 23 in a overall yield of 66 %. Further transformation of 4 with the amines 3 and 5 yielded enantiopure emetine (1) and tubulosine (2), respectively. In addition, starting from 19 the novel benzoquinolizidine alkaloid 34 was synthesised; this compound resembles the vallesiachotamine alkaloid dihydroantirhin 31, which has not been isolated so far but probably must also exist in nature.     

An allyltitanium derived from acrolein 1,2-dicyclohexylethylene acetal and (eta(2)-propene)Ti(O-i-Pr)(2) as a chiral propionaldehyde homoenolate equivalent that reacts with imines with excellent stereoselectivity. An efficient and practical access to optically active gamma-amino carbonyl compounds

A chiral allyltitanium compound 2, prepared in situ by the reaction of optically active acrolein 1,2-dicyclohexylethylene acetal (3) with (eta(2)-propene)Ti(O-i-Pr)(2) (1), reacts with a variety of acyclic and cyclic imines 4 in a regiospecific way to afford alpha-addition products 5 as a mixture of the E- and Z-isomers in good combined yield, where the former is predominant in a ratio of 92:8 to >95:5. The mixture of (E)- and (Z)-5 and pure (E)-5 which could be isolated in several cases were respectively converted to the corresponding beta-amino ester 6 to confirm the absolute configuration and enantiomeric purity. The ee of the newly formed asymmetric center of 5 is more than 78% for the mixture of (E)- and (Z)-5 and more than 96% for pure (E)-5. By taking advantage of the versatility of the vinyl ether moiety in 5, optically active gamma-amino aldehydes 8, gamma-amino aldehyde acetals 7 and 10, gamma-amino acids 9, beta-amino esters 6, and pyrrolidinoisoquinolines 12 were readily prepared. In the reaction of 2 with optically active alpha-silyloxyimine 4n, remarkable double stereodifferentiation was observed; thus, the reaction of 2 derived from (S,S)- or (R,R)-3 provided syn- and anti-5n in a ratio of 55:45 or 0:100, respectively. Meanwhile, the stereochemistry of the product in the reaction of 2 with beta-silyloxyimine 4o was controlled mainly by 2. Thus, the reaction of beta-silyloxyimine 14 with 2 derived from 1 and (R,R)-3 afforded gamma-silyloxyimine 15 with 92% diastereoselectivity, from which 4-amino-6-hydroxypentadecanal dimethyl acetal (13), a key intermediate for the synthesis of batzelladine D, was synthesized.     

Synthetic studies of the HIV-1 protease inhibitive didemnaketals: stereocontrolled synthetic approach to the key mother spiroketals

The stereocontrolled synthesis of (2S,4R,6R,8S,10S,1'R,1' 'R)-2(acetylhydroxymethyl)-4,10-dimethyl-8(isopropenylhydroxymethyl)-1,7-dioxaspiro[5,5]undecane (4a) and its C1' '-epimer (4b), the key mother spiroketals of the HIV-1 protease inhibitive didemnaketals from the ascidian Didemnum sp., has been carried out through multisteps from the natural (R)-(+)-pulegone, which involved the diastereoselective construction of four chiral carbon centers(C-2, C-6, C-8, and C-1') by intramolecular chiral induce.     

New resolution of 2-formyl-1,4-dhp derivatives using CIDR methodology. Facile access to new chiral tricyclic thiolactam

(R)- and (S)-alpha-phenylethylamine (alpha-PEA: 7) have been used separately to resolve successfully a racemate 2-formyl-1,4-DHP derivative 4. The process was based on the difference of the solubility of both Schiff bases (6) since one of them crystallized out from the solution. These imines obtained by condensation of (R)-alpha-PEA (7) or (S)-alpha-PEA (7) with aldehyde (rac-4) were separated and analyzed by X-ray diffraction, and their exposition to an hydrochloric hydrolysis conditions led to the enantiopure (4R)-4 or (4S)-4 in excellent yields. Separate condensation of other chiral (8 and 13) and racemic (18) amino thiols as auxiliary with rac-4, (4S)-4, or (4R)-4 is accompanied by an in situ crystallization-induced dynamic resolution, whereby one distereomer of thiazole template selectively precipitates and can be isolated by simple filtration in 76-82% yield with dr > 99. The thiazole species isolated from this process resulted from an amino aldehyde condensation followed by a spontaneous thiol-imine cycloaddition. Finally, the racemate (+/-)-(4R,2'R)-19 and the diastereomerically pure homologous (4S,2'R)-23 and (4R,2'S)-20 (obtained in good yields (79-82%) from 2-aminoethanethiol (18) and 2-formyl-1,4-DHP derivative rac-4, (4S)-4, or (4R)-4, respectively) were converted conveniently in a one-pot procedure into newly tricyclic thiolactams in the DHP series in racemic ((+/-)-(6R,9bR)-21, 72% yield)) and enantiopure ((6S,9bR)-24, 71% yield); (6R,9bS)-24, 70% yield) forms.