检索结果-南通市图书馆

Enantioselective addition of diethylzinc to aryl aldehydes catalyzed by 1,2,3,4-tetrahydroisoquinoline β-amino alcohol

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2010年第3期21卷 309-311页

作者： Geng Xu[a] zhan zhu liu[a] [a] Key Laboratory of Bioactive Substances Resources Utilization of Chinese Herbal Medicine (Peking Union Medical College) Ministry of Education. Institute of Materia Medica Peking Union Medical College & Chinese Academy of Medical Sciences Beijing 100050 China

A highly effective,new chiral 1,2,3,4-tetrahydroisoquinoline catalyst 1 for the diethylzinc addition to aryl aldehydes has been *** 10 mol%of this chiral catalyst,secondary alcohols can be obtained in up to 87%yield a... 详细信息

关键词： β-Amino alcohol Tetrahydroisoquinoline Diethylzinc Asymmetric addition

Synthesis of new chiral 1,2,3,4-tertrahydroisoquinoline β-amino alcohol for asymmetric diethylzinc addition to aryl aldehydes(Ⅰ)

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2009年第12期20卷 1393-1396页

作者： Geng Xu zhan zhu liu Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine (Peking Union Medical College) Ministry of Education Institute of Materia Medica Peking Union Medical College & Chinese Academy of Medical Sciences Beijing 100050 China

Four new chiral 1,2,3,4-tetrahydroisoquinoline-derived G-amino alcohols were synthesized from commercially available LDOPA. These ligands were evaluated in the asymmetric addition of diethylzinc to benzaldehydes and showed different catalytic activities （up to 86% ee）. The solvent played an important role in the enantioselective process. The transition state models were proposed to explain the reversion of the product configuration.

关键词： β-Amino alcohol Tetrahydroisoquinoline Diethylzinc Asymmetric addition

Synthetic Studies of Et-743, Preparation of A Racemic Amino Alcohol Precursor

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2003年第11期14卷 1127-1129页

作者： zhan zhu liu Shi Zhi CHEN Institute of Materia Medica Chinese Academy of Medical Sciences&Peking Union Medical CollegeBeijing 100050

A mild two-step method was used to cleave the lactam ring of the tricyclic intermediate 1. A key racemic amino alcohol precursor 5 for the construction of Et-743 skeleton was synthesized from 1 through four steps in ... 详细信息

关键词： Et-743 lactam cleavage.

A Case of Abnormal Bishler-Napieralski Cyclization Reaction,Leading to Form Benzyl Oxazole Derivatives

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2001年第3期12卷 195-196页

作者： zhan zhu liu Shi Zhi CHEN Institute of Materia Medica Chinese Academy of Medical Sciences&Peking Union Medical CollegeBeijing 100050

A benzyl oxazole compound 3 was obtained with an excellent yield of 90% when N-acetyl-(2'-methoxy-4',5'-methylenedioxy)-phenylalanine methyl ester 1 was refluxed in POCl1/benzene. However, the anticipated product 3,4-dihydrosioquinoline-3-carboxylic acid methyl ester 2 could not be found. The mechanism was discussed in this article.

关键词： N-Acetyl amino acid oxazole Bishler-Napieralski reaction.

Construction of the Skeleton of Phthalascidin, Mechanism of the Formation of the Key Tricyclic Lactam Intermediate

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2002年第8期13卷 701-704页

作者： zhan zhu liu Ye WANG Shi Zhi CHEN Institute of Materia Medica Chinese Academy of Medical Sciences&Peking Union Medical CollegeBeijing 100050

The mechanism of the formation of a key tricyclic lactam intermediate 3 was studied. It was found that the E-form compound 3 was transformed from the Z-form compound 4. The formation of 4 was a kinetically controlled process while the formation of 3 was a thermodynamically favorable one. A possible mechanism was given in this paper.

关键词： Lactam phthalascidin mechanism Et-743.

Synthesis and cytotoxic activities of a series of novel N-methylbisindolylmaleimide amino acid ester conjugates

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2012年第4期23卷 462-465页

作者： Ke Wang Zheng Yan Nan Wang zhan zhu liu State Key Laboratory of Bioactive Substance and Function of Natural Medicines Institute of Materia MedicaPeking Union Medical College and Chinese Academy of Medical SciencesBeijing 100050China Beijing Key Laboratory of Active Substance Discovery and Druggability Evaluation Institute of Materia MedicaPeking Union Medical College and Chinese Academy of Medical SciencesBeOing 100050China

A series of novel N-methylbisindolylmaleimides and natural amino acid conjugates were synthesized and evaluated for their inhibitory activity against six tumor cell *** of the compounds exhibited moderate in vitro cyt... 详细信息

关键词： Bisindolylmaleimide Amino acid Synthesis Cytotoxicity

New Approach to Synthesis of 6,7-Dimethoxyisatin

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2003年第5期14卷 468-470页

作者： Hong Min MA zhan zhu liu Shi Zhi CHEN Institute of Materia Medica Peking Union Medical College&Chinese Academy of Medical SciencesBeijing 100050

A new approach to synthesis of 6,7-dimethoxyisatin is reported. 2-nitro-3, 4- dimethoxy mandelonitrile in glacial acetic acid was treated with the solution of stannous chloride in hydrochloric acid to give 6, 7-dimet... 详细信息

关键词： Isatin stannous chloride mandelonitrile synthesis.

Formation of Benzyl Oxazole, A Competitive Path with the Classical Bishler-Napieralski Reaction

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2001年第11期12卷 947-950页

作者： zhan zhu liu Ye Feng TANG Shi Zhi CHEN Institute of Materia Medica Chinese Academy of Material Sciences&Peking Union Medical CollegeBeijing 100050

Several aromatic ring-substituted N-acetyl-phenylalanine methyl esters were treated with POCl3 in refluxing benzene, which is the typical condition of B-N reaction. It was found that the normal B-N product 3, 4-dihydroisoquinoline-3-carboxylic acid methyl ester and/or 5-benzyl-2-methyl-4-methoxy oxazole could be obtained. The result depended mainly upon the electron-donating property of the substitutes on the benzene ring. Strong electron-donating groups located at para- or ortho- to the cyclization site will facilitate the formation of the normal B-N product 2. On the other hand, the absence or weak electron-donating groups tended to yield the oxazole product 3. It was established that the formation of benzyl oxazole is the competitive path with the B-N reaction. In this article, an explanation was given based on the mechanism of Bishler-Napieralski reaction.

关键词： Bishler-Napieralski reaction benzyl oxazole 1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid N-acetyl-phenytalanine methyl ester

Regioselective Bromination of 3, 4-Dimethoxytoluene with N-Bromosuccinimide

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2003年第4期14卷 371-374页

作者： Hong Min MA zhan zhu liu Shi Zhi CHEN Institute of Materia Medica Peking Union Medical College&Chinese Academy of Medical SciencesBeijing 100050

The selective brominations of 3, 4-dimethoxytoluene with N-bromosuccinimide were reported. The nuclear and side-chain brominated products were obtained under different reaction conditions. The mechanism was also discu... 详细信息

关键词： Bromination 3, 4-dimethoxy toluene N-bromosucinimide regioselective bromination.