关键词： 手性   铜催化剂   环丙烷羧酸酯   制备  

摘要： ３类手性配体ｄ－１０－樟脑磺酸及其衍生物，α－（－）－羟蒎酮及其衍生物，双唑啉衍生物分别与铜（Ⅱ）形成手性铜配合物，催化重氮乙酸酯与１，１－二苯乙烯或异丁烯的环丙烷化加成反应，得到光学活性环丙烷羧酸酯，不对称诱导最高可达９５％ｅ．ｅ．

关键词： 不对称合成   光学活性   消旋化   孤电子对   亚砜   化学工作者   化学合成方法   立体选择性   格氏试剂   环氧化  

摘要： 手性亚砜具有孤电子对,结构上呈锥形结构,由于R₁≠R₂,所以呈光学活性.又由于手性亚砜的消旋化能量和消旋温度较高（分别为146～176kJ/mol和200℃）,所以在反应过程中手性亚砜不易发生消旋化,是比较稳定的.虽然人们早已了解这一点,但是真正合成与应用手性亚砜还是七十年代才发展起来的.近年来,手性亚砜作为合成试剂,随着化学工作者对它研究的进一步深入和有机化学合成方法的不断创新与完善,它在有机合成特别是在不对称合成这一重要合成领域中的应用更加广泛。

关键词： .Recent advances   asymmetric hydroboration   scope   asymmetric reduction   successes   CHCH   Pure enantiomers   asymmetric homologation   crotylboration   boron route   Chiral organoboranes   general asymmetric synthesis   Fig Asymmetric  

摘要： Chiral organoboranes, readily available via asymmetric hydroboration or the Matteson asymmetric homologation reaction, have been successfully utilized for a general asymmetric synthesis of pure enantiomers. The recent continued successes achieved in our three-pronged approach to asymmetric synthesis - (1) asymmetric hydroboration, (2) asymmetric reduction, and (3) asymmetric allyl- and crotylboration, coupled with developments in asymmetric homologation, reveal the broad scope of these methodologies for the synthesis of stereoisomers in purities approaching 100 % ee.

关键词： 不对称合成方法   合成研究   辅助物   反应温度   苯乙酸   芳香族羧酸   烷基   取代基  

摘要： α—烷基—α—羟基苯乙酸的不对称合成研究王大升，恽榴红（军事医学科学院毒物药物研究所）对三种不同的不对称合成方法进行了研究，系统地考察了α－烷基－α－羟基苯乙酸的不对称合成方法，研究了手性辅助物的合成，不对称诱导机制，有机锌试剂的反应性能，反应温度和...

关键词： 樟脑   硫亚胺   不对称合成   手性胺  

摘要： 合成了四种含樟脑巯基手性助剂的光学活性的硫亚胺化合物。

关键词： 金鸡纳碱   化合物   不对称合成   催化   鎓盐  

摘要： 本文介绍了金鸡钠碱及其鎓盐作为催化剂催化的一些反应,这些反应包括C-C,C-P,C-S键的形成.本文还讨论了催化反应的特点及催化剂结构与催化活性之间的关系,金鸡纳碱催化属于一般的不对称诱导催化,而其鎓盐则属于不对称相转移催化.

摘要： This thesis is presented in two parts. Part 1. Asymmetric Synthesis via Chiral Sulfoximines. Chapter 1. Asymmetric Synthesis of Chiral Alcohols and Ketones from Sulfoximines The application of chiral sulfoximines to the asymmetric synthesis of chiral alcohols and ketones is described historically in Chapter 1. Chapter 2. Asymmetric Synthesis of Chiral Alcohols and Chiral Ketones from (+)-(S)-N-t- B u t y l d i p h e n y l s i l y l - S - M e t h y l - S-Phenylsulfoximine. The synthesis and applications of (+)-(S)-N-t-butyldiphenylsilyl- S-methyl-S-phenylsulfoximine to the asymmetric synthesis of chiral alcohols is described in Chapter 2. The diastereoselectivities of all these reactions have been documented. The stereochemistry of some major adducts was determined by X-ray crystallography. Two racemic ketones, 2-tbutyl- cyclohexanone and 2-methyl-cyclohexanone were successfully resolved by diastereoselective addition of lithiated (+)-(S)-N-t-butyldiphenylsilyl-S-methyl-S-phenylsulfoximine, followed by separation of the diastereomeric adducts and then thermolysis. Chapter 3. Diastereoselective Conjugate Addition Reactions of Lithiated Allylic Sulfoximine to Cyclic and Acyclic Enones. The asymmetric conjugate addition reactions of racemic S-allyl S-phenyl-N-tosylsulfoximine with Michael acceptors and carbonyl compounds is described in Chapter 3. The diastereoselective ratio of all reactions have been documented. The stereochemistry of two major adducts was determined by Xray crystallography analysis. Part 2. Diasteroselective Synthesis of p-Azido Sulfoxides. Chapter 4. Addition of Nitrogen Nucleophiles to Vinyl Sulfoxides. A survey of the conjugate addition reactions of vinyl sulfoxides with nitrogen nucleophiles is described. Chapter 5. Addition of Azide to Vinyl Sulfoxides. The conjugate addition reaction of azide ion to p - a r y l - a - phenylsulfinylacrylates is reported in Chapter 5. Reactions in the presence of acetic acid gives triazoles while reactions in the

关键词： 手性化合物   不对称合成   膦配体  

摘要： 不对称催化是由潜手性反应物合成光活性化合物的有效途径,α,β-不饱和氨基酸的氢化立体选择性已达90％以上,L-Dopa的工业化生产则标志着不对称催化氢化开始走向实际应用。高选择性的催化剂一般是一价铑的手性双膦配体络合物,其中DIOP[2,3-O-异丙叉-

关键词： 羰基   不对称合成   加成反应