斑蝥素的常压合成

报道了一种斑蝥素的常压合成方法。以3-氧代-4-甲酸甲酯四氢噻吩为起始原料,经氰基化和腈醇脱水反应制得3-氰基-4-甲酸甲酯-2,5-二氢噻吩(1); 1水解制得2,5-二氢噻吩-3,4-二羧酸(2); 2在二氯亚砜作用下脱水制得关键中间体2,5-二氢噻吩-3,4-二羧酸酐（3）; 3依次经D-A反应和Raney Ni催化加氢的脱硫反应合成了斑蝥素(5),总收率38%,其结构经¹H NMR, ¹³C NMR和MS（ESI）确证。研究了离子液体、反应时间和反应温度对D-A反应的影响。确定D-A反应的较优条件为：[BMIM]·BF₄为离子液体,于35 ℃反应20 h,斑蝥素前体产率为86%。     

3″,3″-二甲基吡喃[3’,4’]2,4,2’-三羟基查尔酮的首次全合成

以2,4-二羟基苯乙酮和2,4-二羟基苯甲醛为起始原料,经过C-异戊烯基化、保护酚羟基、羟醛缩合、去保护基反应首次成功地完成了天然产物3″,3″-二甲基吡喃[3’,4’]2,4,2’-三羟基查尔酮的全合成,总产率18.4%,其结构经1H NMR,IR和MS表征。中间体8未见文献报道。     

3",3"-二甲基吡喃[3',4']2,4,2'-三羟基查尔酮的首次全合成

以2,4---羟基苯乙酮和2,4-二羟基苯甲醛为起始原料,经过C-异戊烯基化、保护酚羟基、羟醛缩合、去保护基反应首次成功地完成了天然产物3",3"-二甲基吡喃[3’,4’]2,4,2’-三羟基查尔酮的全合成,总产率18.4％,其结构经1H NMR,IR和MS表征.中间体8未见文献报道.     

一种简便的3-巯基-5-羟基-1，2，4-三嗪的合成方法

1，2，4-三嗪类化合物具有干扰核酸代谢作用，多年来受到药物化学工作者们的重视。3-巯基-5-羟基-1，2，4-三嗪(I)是合成1，2．4-三嗪类化合物的一种重要中间体。     

HIV-1 RT抑制剂研究I.1,3-二苄基-6-(3,4-环氧丁基)尿嘧啶的合成

报道了1,3-二苄基-6-(3,4-环氧丁基)尿嘧啶的合成新方法.以6-甲基尿嘧啶(1)为起始物,经1,3-二苄基-6-甲基尿嘧啶(2)及未见文献报道的1,3-二苄基-6-(3-丁烯基)尿嘧啶(3)和1,3-二苄基-6-(3-羟基-4-溴丁基)尿嘧啶(4),首次高收率合成了1,3-二苄基-6-(3,4-环氧丁基)尿嘧啶(5),并对其化学结构进行了表征.     

巴戟天内生真菌Trichoderma spirale A725中两个新的聚酮类化合物(英文)

综合运用硅胶柱色谱、反相硅胶柱色谱、Sephadex LH-20凝胶柱色谱以及制备型高效液相色谱技术对药用植物巴戟天内生真菌Trichoderma spirale A725的次生代谢产物进行分离纯化,得到6个聚酮类化合物,采用多种现代波谱技术确定其结构,分别为:6-羟基-4-异丙基-1,8-二甲基螺环[4.5]癸-1,8-二烯-7-酮(1),2-羟基-2,5-二甲基-7-氧代-5,7-二氢-2H-呋喃[3,4-b]吡喃-4-羧酸(2), 3-乙基-4-羟基-6-甲基-二氢-吡喃-2-酮(3),苯乙内酯A (4), 3-羟基-5-(4-羟基苄基)二氢呋喃-2(3H)-酮(5), 4-乙酰-3-羟基-6-甲基吡喃-2-酮(6).其中化合物1和2为新化合物,化合物3为新天然产物.此外,利用四株肿瘤细胞株(Hep G-2、MCF-7、SF-268及A549)对化合物1~6细胞毒活性进行评估,结果表明化合物1~6对上述肿瘤细胞均无明显的细胞毒活性.     

3,4-二氢-1-(4-哌啶基)-2(1H)-喹啉酮的合成

以苄胺为原料,经6步反应得到新型抗高血压药OPC-21268的中间体3,4-二氢-1-(4-哌啶基)-2(1H)-喹啉酮,总收率13．9％．     

有机催化不对称[3+3]环化合成新型光学活性稠合多环3,4-二氢吡喃并[4,3-b]吡喃-5-(2H)-酮（英文）

发展了一种手性双功能方酰胺催化的4-羟基-2(H)-吡喃并[2',3':4,5]吡喃并[2,3-c]吡唑-2,5(7H)-二酮与(E)-2-硝基烯丙基醋酸酯之间的对映选择[3+3]环化反应,为立体选择构筑稠合多环3,4-二氢吡喃并[4,3-b]吡喃-5-(2H)-酮骨架提供了途径.在衍生自(1R,2R)-1,2-二苯基乙-1,2-二胺的手性双功能方酰胺的催化下,以中等至较高产率、高的反式选择性和中等至优秀的对映选择性得到了一系列具有两个连续手性中心的新型稠合多环3,4-二氢吡喃并[4,3-b]吡喃-5-(2H)-酮衍生物.     

双(2-取代-3-羟基-4-吡喃酮)合铜(II)配合物的合成和降血糖作用

合成了双(2-取代-3-羟基-4-吡喃酮)合铜(II)配合物,采用元素分析、质谱、红外光谱、电子光谱、电子自旋共振谱表征了它们为平面正方型配合物,中心离子和配体的物质的量比为1∶2.在STZ-糖尿病小鼠模型上,其中双(2-乙基-3-羟基-4-吡喃酮)合铜(II)在10mg/kg的剂量下灌胃给药,能增加血清胰岛素的合成和分泌、降低糖尿病小鼠的血糖水平,显示出良好的抗糖尿病的作用.该配合物毒性低,对正常小鼠灌胃给药的半数致死量LD50是855.9mg/kg.     

两种苯并二氢吡喃-4-酮衍生物的合成

分别以间甲氧基苯酚与间苯二酚为原料,经过3步合成了(E)-7-甲氧基-3(4-甲氧基苯哑甲基)与(E)-7-羟基-3-(3',4',5'-三甲氧基苯哑甲基)取代的苯并二氢吡喃-4-酮.合成路线简单,易于操作,两者的最终收率分别为20.1%和15.3%.     

二氧化碳和丙烯直接合成甲基丙烯酸的NiPMo/TiO2催化剂的研究

用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%.     

Synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives

Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields.     

α-Amino acid derived enaminones and their application in the synthesis of N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates and other heterocycles

A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.     

Specific intramolecular aromatic CH insertion of diazosulfonamides

The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp³)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp²)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp²)?H and aliphatic 1,5- and 1,6-C(sp³)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp³)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp²)?H insertion.     

A general and convenient synthesis of 4-(tosylmethyl)semicarbazones and their use in amidoalkylation of hydrogen,heteroatom, and carbon nucleophiles

A general synthesis of previously unknown semicarbazone-based α-amidoalkylating reagents, 4-(tosylmethyl)semicarbazones, has been developed. The synthesis involved three-component condensation of semicarbazones of aliphatic or aromatic aldehydes with the same or other aldehydes and p-toluenesulfinic acid. The scope and limitations of this reaction were investigated. The compounds obtained were demonstrated to be an efficient α-(4-semicarbazono)alkylating agents. They were reacted with H- (sodium borohydride), O- (sodium methylate), S- (sodium phenylthiolate), N- (pyrrolidine, sodium succinimide), P- (trialkyl phosphites), and C-nucleophiles (sodium diethyl malonate) to give the corresponding products of the tosyl group substitution, 4-substituted semicarbazones, including analogues of nitrofurazone. Among the prepared compounds tested in vitro for antibacterial and antifungal activity, three nitrofuryl-containing semicarbazones exhibited high biological activities with minimum inhibitory concentration (MIC) values of 8–32 μg/mL.     

Synthesis of novel chiral bidentate hydroxyalkyl-N-heterocyclic carbene ligands and their application in palladium-catalyzed Mizoroki–Heck couplings and asymmetric addition of diethylzinc to benzaldehyde

A small library of new chiral bidentate hydroxyalkyl-imidazolium salts 1 is conveniently synthesized on multi-gram scale from inexpensive and commercially available chiral pool amino acids. The corresponding carbenes, generated by deprotonation of imidazolium salts 1, in combination with palladium(II) chloride were tested in the Mizoroki–Heck coupling reaction. The most significant results in terms of yields and reactivities were achieved with low catalyst loading. The catalytic activities of these imidazolium salts were also investigated in the asymmetric addition of diethylzinc to benzaldehyde. The use of MgO nanoparticles as an additive in conjunction with these ligands played a crucial role in increasing the efficiency of these reactions.     

N-Heterocyclic carbene-palladacyclic complexes: synthesis,characterization and their applications in the C-N coupling and α-arylation of ketones using aryl chlorides

N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%).     

Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction

In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments.     

Iodine-mediated oxidative Pictet-Spengler reaction using terminal alkyne as the 2-oxoaldehyde surrogate for the synthesis of 1-aroyl-β-carbolines and fused-nitrogen heterocycles

An efficient iodine-mediated oxidative Pictet-Spengler reaction in dimethyl sulphoxide (DMSO) using terminal alkynes as the 2-oxoaldehyde surrogate for the synthesis of aryl (9H-pyrido[3,4-b]indol-1-yl)methanones is described. The scope of the protocol includes the total synthesis of Fascaplysin, Eudistomins Y₁ and Y₂. The methodology is extended for preparing pyrrolo[1,2-a]-quinoxaline and indolo[1,5-a]quinoxaline derivatives. The utility of 1-aroyl-β-carbolines was demonstrated by performing palladium-catalyzed β-carboline directed ortho-C(sp2)-H functionalization of the phenyl ring with thiomethyl (SMe) group using DMSO as source and for accessing 4-aryl-canthin-6-ones.     

Facile synthesis of bicyclic 1-arylpyrazol-5-ones

In this Letter, we described a facile method for constructing fused bicyclic 1-arylpyrazol-5-one ring system. We employed various methylene-containing carboxylic acids as the substrates and proved that the pyrazolone ring closure requires activated methylene group in intermediate II. Accordingly, a series of structurally diversified, fused bicyclic 1-arylpyrazol-5-ones was prepared in moderate to high yields using the requisite substrates.