Semicorrin metal complexes as enantioselective catalysts. Part 2. Enantioselective cyclopropane formation from olefins with diazo compounds catalyzed by chiral (semicorrinato)copper complexes
作者:Hugo Fritschi、Urs Leutenegger、Andreas Pfaltz
DOI:10.1002/hlca.19880710621
日期:1988.9.28
were obtained (Table 2). Usually, the reactions were carried out using bis(semicorrinato)copper(II) complexes as precatalysts. In order to produce active catalysts, these complexes had to be activated first by heating in the presence of diazoacetate or by treatment with phenylhydrazine. Experiments with (semicorrinato)copper(I) complexes, prepared in situ from copper(I) tert-butoxide (Scheme 4), suggest
Highly Diastereoselective Synthesis of Vinylcyclopropane Derivatives with (−)-8-Phenylmenthol as Chiral Auxiliary
作者:Song Ye、Yong Tang、Li-Xin Dai
DOI:10.1021/jo010121x
日期:2001.8.1
telluronium allylide 4, generated in situ from the corresponding telluronium salt in the presence of LiTMP, reacted with (-)-8-phenylmenthyl alpha,beta-unsaturated esters to afford trans-2-silylvinyl-trans-3-substituted cyclopropyl esters with high diastereoselectivity in high yields. The absolute configuration was determined by chemical transformation. A mechanistic rationale is proposed.
Syntheses of dictyopterene B (hormosirene) and its enantiomer via asymmetric ScN′ reactions
作者:Dieter Dorsch、Erika Kunz、Günter Helmchen
DOI:10.1016/s0040-4039(00)98287-x
日期:1985.1
HEPATITIS C INHIBITOR TRI-PEPTIDES
申请人:BOEHRINGER INGELHEIM (CANADA) LTD.
公开号:EP1105413B1
公开(公告)日:2009-04-29
Synthesis of the Prototypical Cyclopropyl Dipeptide Mimic and Evaluation of Its Turn-Inducing Capability
作者:Albane Neckebroeck、Sharon M. Kelly、Brian O. Smith、J. Stephen Clark
DOI:10.1021/acs.joc.1c02344
日期:2022.1.7
cyclopropyl dipeptide mimic have been synthesized and evaluated. The mimic derives its turn-inducing capabilities solely from the cyclopropyl group and without the conformational biasing that would be provided by side-chain substituents. The mimic and peptide-mimic hybrids prepared from it have been studied using a combination of spectroscopic techniques (NMR, IR, and CD). The dipeptide mimic itself displays
已经合成和评估了一种新的诱导转角的环丙基二肽模拟物的 (+) 和 (-) 对映异构体。该模拟物仅从环丙基基团中获得其转角诱导能力,而没有侧链取代基提供的构象偏差。已经使用光谱技术(NMR、IR 和 CD)的组合研究了从中制备的模拟物和肽模拟物杂化物。二肽模拟物本身在有机溶剂中显示出分子内氢键,这与在天然肽转角中观察到的不同。相比之下,更精细的肽模拟杂合体表现出氢键特征,该特征随溶剂而变化,但与天然 β-转角的四肽部分 ( i → i + 3) 中发现的结构一致。