关键词： 雪松烯衍生物   手性助剂   不对称  

摘要： ***利用α-蒎烯作为手性助剂合成了多种手性硼试剂,并成功地将它们用于不对称合成反应,对不对称有机合成的发展作出了杰出的贡献.工作者课题组用雪松烯制得相应的手性硼烷,并成功地进行了不对称硼氢化反应、不对称还原和不对称烯丙基化等反应.该论文是工作者对雪松烷基作为手性助剂的性质有了较为深刻认识的基础上,合成了雪松烯的两个衍生物-雪松烷二醇和雪梭烷氨基醇,研究了它们在不对称合成中的应用,得出了如下结果:雪松烷二醇硼酸酯的不对称同系化反应;雪松烷二醇硼烷对前手性酮的不对称还原反应;雪松烷氨醇催化下的不对称还原反应;雪松烷氨醇催化下前手性酮不对称还原反应的理论研究.

关键词： 金属卟啉   不对称催化   手性识别   轴向配位   不对称合成   分子力学MM2方法   分子静电势   摩擦发光  

摘要： 该文以L-(+)-酒石酸作为手性源,合成了一类新型的手性金属卟啉配合物,并初步研究了这类手性卟啉配合物对某些咪唑类含氮配体进行轴配反应的热力学性质;对于反应过程中出现的各类实验进行了探讨;比较全面的对化合物结构和热力学性质之间的关系进行了考查,并从理论上加以解释;对于应用于防伪技术的发光材料也进行了初步的研究.

关键词： 萘普义生   不对称合成   消旋萘普生   发   工业化生产(S)-萘普生的方法  

摘要： 该文主要从工业应用角度研究了萘普义生的不对称合成和消旋萘普生的拆分,开发出适用于工业化生产(S)-萘普生的方法.

关键词： 苯并二氧化六环新木脂素   黄酮木脂素立体选择性合成   合成路线   不对称合成  

摘要： 该论文对一些苯并二氧六环新木脂素和黄酮木脂素进行了全合成研究,内容包括以下七部分:一、苯并二氧六环新木脂素及黄酮木脂素的研究进展.综述了近年来苯并二氧六环类木脂素及黄酮木脂素的研究进展,重点论述了建立苯并二氧六环及黄酮环的黄酮环的构筑方法.二、Methyl ether of Americanol A和Methyl ether of Americanin A的合成研究.三、Isoamericanol A,Isoamericanin A(±)-3-甲氧基-4,9,9\'-三羟基苯并二氧六环木 脂素及其衍生物的全成研究.四、(±)-Sinaiticin的首次全合成研究.五、黄酮木脂素Jydnocarpin的首次全合成研究.六、Dimethyl Ethers of Americanol A,Americanin A和Methyl Ether of Silandrin的合成研究.七、(7R,8R)-Hydnocarpin的不对称合成研究.通过对以上六个天然产物、七个衍生物合成,分别建立了两条立体选择性合成苯并二氧六环新木脂素、黄酮木脂素的合成路线,并对其不对称合成做了探索.在此过程中,共涉及了50个化合物的合成,其中33个化合物尚未见文献报道,通过波谱确证了上述化合物的结构.

关键词： 氨基酸   合成   不对称合成   热力学  

摘要： 从热力学角度分析了氨基酸不对称化学合成中光学收率与构型熵及温度的关系。

关键词： oxazoles   marine natural products   oxabicyclic ketones   cytotoxicity   HWE reaction   E,E-selectivity  

摘要： The phorboxazoles A and B are a new class of biologically highly active macrolides. The enantiopure C28-C41 segment containing four stereogenic centers, an E-configurated trisubstituted double bond and the 2,4-difunctionalized oxazole moiety has been prepared in 16 steps in 10% overall yield. The synthesis represents advances in strategy and methodology.

关键词： Hydrogen   Hydrocarbons   Catalysts   Catalytic reactions   Hydrogenation  

摘要： A greatly improved process has been developed for synthesis of the glutarate derivative 2, a key intermediate required for Pfizer's drug candoxatril. The cationic (R,R)-Me-DuPHOS-Rh catalyst was found to allow highly efficient and enantioselective hydrogenation of a unique carboxylate substrate (5) to afford the desired product in >99% ee and high yield (95%). The robust nature of the process was validated on a 12 kg reaction scale. A novel mechanism for the hydrogenation process is proposed. Through use of a labile eta(6)-benzene-Rh-Me-DuPHOS complex, the postulated catalytic intermediates have been synthesized by independent means. Detailed spectroscopic analyses of these intermediates corroborate the mechanistic hypotheses. Interconversion of these key catalytic intermediates has been demonstrated.

关键词： ALKYLATION   COMPLEXES  

摘要： Ir-catalysed allylic alkylations of enantiomerically enriched monosubstituted allylic acetates proceed with up to 79% retention of configuration using P(OPh)(3) as ligand;further evidence supports the assumption of sigma-allyl complexes as intermediates, and high regio- and enantioselectivity in asymmetric allylic alkylations of achiral or racemic substrates is achieved with phosphorus amidites as ligands.

关键词： .ethanoate   oxazines   butyldimethylsilyloxy   oxathianes   Piperidineethanols   perhydro   ethan ol  

关键词： Alcohols   Organic compounds   Ligands   Cyclization   Substitution reactions  

摘要： Palladium-catalyzed asymmetric allylic alkylations have been explored in the context of medium-sized ring substrates, intramolecular vs intermolecular processes involving attack on a formally meso pi-allyl intermediate in the desymmetrization, and the presence of electron-withdrawing groups on the cationic pi-allylpalladium intermediate. The synthesis of anatoxin-a, also known as the "very fast death factor", raises all of these questions. Ligands derived from trans-1,2-diaminocyclohexane and 2-diphenylphosphinobenzoic acid effect asymmetric alkylations with an allyl substrate bearing an electron-withdrawing group. On the other hand, a new type of ligand wherein the diamine is derivatized with both 2-diphenylphosphinobenzoic acid and 2-picolinic acid was required to effect asymmetric cyclization to form the 9-azabicyclo[4.2. 1]non-2-ene system. A total synthesis of anatoxin-a from 5-hydroxy-1,8-nonadiene employing a metathesis reaction to form the cycloheptene and a palladium-catalyzed asymmetric cyclization to form the bicyclic ring system is achieved in 15% overall yield.