关键词： isoindolinones   asymmetric synthesis   hydrazones   1,2-addition   N-N bond cleavage  

摘要： The first asymmetric synthesis of 3-aryl substituted 2,3-dihydro-1H-isoindol-1-ones via a tandem nucleophilic 1,2-addition ring closure procedure from SAMP and (or) RAMP hydrazones and subsequent oxidative cleavage of the auxiliary is reported.

关键词： RHODIUM   LACTAMS  

摘要： Catalytic asymmetric synthesis of 4-aryl-2-piperidinones was realized for the first time by asymmetric 1,4-addition of arylboron reagents to 5,6-dihydro-2(1H)-pyridinones in the presence of a chiral bisphosphine-rhodium catalyst. In the reaction introducing 4-fluorophenyl group, the use of 4-fluorophenylboroxine and 1 equiv (to boron) of water at 40 degreesC gave the highest yield of the arylation product with high enantioselectivity (98% ee). The (R)-4-(4-fluorophenyl)-2-piperidinone obtained here is a key intermediate for the synthesis of (-)-Paroxetine.

关键词： Alcohols   Organic compounds   Anions   Stereoselectivity   Conjugate acid-base pairs  

摘要： [GRAPHICS] A practical, chromotography-free asymmetric synthesis was developed for the large scale preparation of an endothelin receptor antagonist 2. This synthesis includes a new efficient process for the preparation of 6-bromo-2,3-dihydrobenzofuran, a stereoselective conjugate addition of an aryllithium followed by stereospecific addition of the Grignard reagent of the top aryl bromide, and an aminophosphate-mediated sterospecific intramolecular enolate alkylation, which led to the formation of the five-membered ring bearing three contiguous asymmetric centers.

关键词： ASYMMETRIC synthesis   ALKALOIDS  

摘要： Several 2,6-disubstituted piperidin-3-ol alkaloids ahve been isolated formProsopis africana,whose leaves have been used in Africa to treat *** these variousnaturally occurring compounds are (+)-prosopinine (1) and (+-)-prosophylline (2).These alkaloidspostracted considerable interest as synthetic targets.A reduction analogue ofprosopinine,(+)-deoxoprosopinine number of syntheses of this derivative have been reported.

关键词： Enantioselective synthesis   Mixtures   Organic compounds   Molecular structure   Piperidines  

摘要： GRAPHICS The intramolecular Mannich reaction of delta -amino beta -keto esters with aldehydes and ketones is a new methodology for the synthesis of polysubstituted piperidines and is illustrated by the concise asymmetric synthesis of the dendrobate alkaloid (+)-241D and its C-4 epimer.

关键词： Peptides and proteins   Stereochemistry   Monomers   Stereoselectivity   Deprotonation  

摘要： [GRAPHICS] The asymmetric synthesis of a fully protected ent-actinoldinic acid derivative 14 is described. As key steps, an enantioselective deprotonation of an arenetricarbonylchromium(0) complex and a diastereoselective Suzuki coupling were applied. The asymmetric centers of the amino acid function were created via stereocontrolled Strecker reactions.

关键词： Enolates   Lactones   Organic compounds   Alkyls   Ketones  

摘要： [GRAPHICS] The L-callipeltose subunit of L-callipeltoside A has been synthesized in 10 steps and 13% overall yield from D-threonine. The key steps are a highly diastereoselective Felkin anti aldol addition to a methyl ketone and a selective methylation of a secondary alcohol in the presence of a secondary carbamate.

关键词： 2-位氧化糖   羰基转位反应   芳胺   氨基糖   不对称合成   α-甲基-D-葡萄糖苷   2-位羰基衍生物  

摘要： A novel carbonyl transposition reaction led by aromatic amines nucleophilic addition to \{2 oxo glycoside\} was discovered. The mechanism of the reaction was provided through tracing the change of 1H NMR of a hemiacetal intermediate which was obtained in the reaction of o phenylene diamine with 2 oxo glycoside. Both the intermediate and the product were identified by FTIR, 1H NMR, 13 C NMR, 1H 1H COSY and 1H 13 C COSY spectra. The other aromatic amines reaction with 2 oxo glycoside also proved the mechanism. This reaction provides a new method for preparing 2 deoxy 2 aromatic amino 3 oxo glycosides, which is a new kind of material used in assymetric synthesis.

关键词： m-甲基-8β-O-肉桂酰基-goniotriol   抗肿瘤   不对称合成  

摘要： 目的　为了研究哥纳香醇甲的构效关系和寻找更高抗肿瘤活性的化合物。方法　以α -D -葡庚糖酸内酯为原料 ,以 9步反应 ,不对称选择性地合成了m -甲基 - 8β -O -肉桂酰基 -goniotriol,总收率为 5 .7% ,并经MTT法检测了它们的抗肿瘤活性。结果　合成了m -甲基 - 8β -O -肉桂酰基 -goniotriol及其 3个中间体 ,均为新化合物。 结论　

关键词： 双E唑啉   手性双E唑啉酮配合物   不对称合成   配体   应用  

摘要： 综述了手性双唑啉配体的主要结构类型 ,并讨论了手性双唑啉铜配合物在不对称Diels Alder反应、Ene反应、Mukaiyamaadol反应、烯丙基氧化、环丙烷化、氮杂环丙烷化等反应中的应用。