Highly Enantioselective Reactions of Cyclohexanone and<i>β</i>,<i>γ</i>-Unsaturated<i>α</i>-Keto Ester: The Tuning of Chemo-selectivities by Secondary and Primary Amine Catalysts
作者:Jianwei Wei、Wengang Guo、Xin Zhou、Xin Du、Yan Liu、Can Li
DOI:10.1002/cjoc.201400431
日期:2014.10
amphiphilic imidazole based secondary and primaryaminecatalysts were synthesized and shown to be very effective with an acid cocatalyst for the asymmetric reaction of cyclohexanone to β,γ‐unsaturated α‐keto ester. Interestingly, primary and secondaryaminecatalysts show different regio‐selectivities in this reaction. Under the catalysis of secondaryamine 1, excellent enantioselectivities were observed for
The electrochemical reduction of O-2 (E = -1.0 V vs SCE) in dipolar aprotic solvents in the presence of CO2 gave a carboxylating reagent (O-2(.-)/CO2) able to convert amines and different types of their derivatives into carbamates. Primary and secondary aliphatic and aromatic amines were converted into the corresponding ethyl carbamates by the addition of EtI to the carbamate anions generated in the first step of the reactions. The yields were dependent on the nucleophilicity of the nitrogen atom. beta-Bromoethyl- and propylamine gave 2-oxazolidinone and tetrahydro-1,3-oxazin-2-one in moderate yields. N-Acyl or N-(alkoxycarbonyl)alkylamines bearing a leaving group at the beta position of the alkyl substituent were converted into 3-substituted-2-oxazolidinones in high yields. By using chiral substrates, enantiopure 3-alkoxycarbonyl(or acyl)-4-substituted oxazolidin-2-ones (70-85% isolated yields) were obtained. This represents a new mild and safe route to these important auxiliaries for asymmetric synthesis. Some limitations of the process are also evidenced and accounted for.
US5244905A
申请人:——
公开号:US5244905A
公开(公告)日:1993-09-14
[EN] N-SUBSTITUTED CYCLOALKYL AND POLYCYCLOAKYL POLYHYDRO- BETA -CARBOLINE-PHENYLALANINE-AND PHENETHYLAMINE DERIVATIVES
申请人:WARNER-LAMBERT COMPANY
公开号:WO1992004348A1
公开(公告)日:1992-03-19
(EN) Novel substituted polyhydro-$g(B)-carboline derivatives useful as agents in the treatment of obesity, hypersecretion of gastric acid in the gut, gastrin-dependent tumors, or as antipsychotic agents are disclosed. Further the compounds are antianxiety agents and antiulcer agents. Further, the compounds are useful for treating and/or preventing panic attacks. They are agents useful for preventing the response to withdrawal from chronic treatment with or use of nicotine, caffeine, diazepam, alcohol, cocaine or opioids. Also disclosed are pharmaceutical compositions and methods of treatment using the compounds as well as processes for preparing them and novel intermediates useful in their preparation. An additional feature of the invention is the use of the subject compounds in diagnostic compositions.(FR) Nouveaux dérivés polyhydro-$g(B)-carboline substitués utiles comme agents dans le traitement de l'obésité, de l'hypersécrétion d'acide gastrique dans l'intestin, de tumeurs engendrées par la gastrine ou comme agents neuroleptiques. De plus, les composés sont des agents anxiolitiques et contre les ulcères. Les composés sont également utiles dans le traitement et/ou la prévention de crises de panique. Ils constituent des agents utiles prévenant la réaction suivant l'arrêt d'un traitement chronique à la nicotine, la caféine, le diazépam, l'alcool, la cocaïne ou des opioïdes. L'invention concerne également des compositions pharmaceutiques ainsi que des méthodes de traitement utilisant les composés, et des procédés de préparation de ces derniers ainsi que de nouveaux intermédiaires utiles dans leur préparation. Une caractéristique supplémentaire de l'invention est l'emploi desdits composés dans des compositions de diagnostic.
Synthesis of the orthogonally protected amino alcohol Phaol and analogs
作者:Jo Nelissen、Koen Nuyts、Wim Dehaen、Wim M. De Borggraeve
DOI:10.1002/psc.1362
日期:2011.7
The development of a multigram synthesis of the orthogonally protected amino acid‐derived Phaol [2‐[(2S)‐2‐amino‐3‐phenylpropyl]amino}ethanol] is described. The goal of this work is to synthesize an orthogonally protected Phaol in a multigram scale up to 10 g (Cbz‐Phaol), so it can be used in solution‐based peptide synthesis of peptaibols. Two synthetic schemes were proposed and examined. Between