.omega.-Heteroaroyl(propionyl or butyryl)-L-prolines
申请人:American Cyanamid Company
公开号:US04299769A1
公开(公告)日:1981-11-10
This disclosure describes novel substituted .omega.-heteroaroyl(propionyl or butyryl)-L-prolines and the esters and cationic salts thereof which are useful as hypotensive agents in mammals.
Catalyst-Controlled, Enantioselective, and Diastereodivergent Conjugate Addition of Aldehydes to Electron-Deficient Olefins
作者:S. B. Jennifer Kan、Hiroki Maruyama、Matsujiro Akakura、Taichi Kano、Keiji Maruoka
DOI:10.1002/anie.201705546
日期:2017.8.1
A chiral-amine-catalyzed enantioselective and diastereodivergent method for aldehyde addition to electron-deficient olefins is presented. Hydrogen bonding was used as a control element to achieve unusual anti selectivity, which was further elucidated through mechanistic and computational studies.
Base-Promoted Annulative Difluoromethylenation of Enaminones with BrCF<sub>2</sub>CO<sub>2</sub>Et toward 2,2-Difluorinated 2,3-Dihydrofurans
作者:Jinbiao Ying、Ting Liu、Yunyun Liu、Jie-Ping Wan
DOI:10.1021/acs.orglett.2c00671
日期:2022.4.1
A practical method for the synthesis of 2,2-difluorinated 2,3-dihydrofurans has been established via the [4 + 1] annulation of enaminones and BrCF2CO2Et with Na2CO3 promotion. This new protocol does not employ any transition metal reagent and enables the annulative difluoromethylation by the partial cleavage of the C═C double bond. In addition, the further treatment with hydrochloric acid in one pot
通过烯胺酮和BrCF 2 CO 2 Et 与Na 2 CO 3促进的[4 + 1] 环化,建立了一种合成2,2-二氟代2,3-二氢呋喃的实用方法。该新方案不使用任何过渡金属试剂,并通过 C=C 双键的部分裂解实现环状二氟甲基化。此外,在一锅中用盐酸进一步处理会通过形式烯胺酮 C-N 羧化生成 β-酮烯酸(4-氧代-2-丁烯酸)。
Stereoselective sodium borohydride reduction, catalyzed by manganese(II) chloride, of γ-oxo-α-amino acids. A practical approach to syn-γ-hydroxy-α-amino acids
A highly stereoselective reduction of γ-oxo-α-amino acids by sodium borohydride in the presence of a catalytic amount of manganese(II) chloride gives syn-γ-hydroxy-α-amino acids. Enantiomerically pure syn-(2S,4R,1′S)-4-aryl-4-hydroxy-2-(1′-phenylethylamino)butanoic acids form stable gels in methanol.
A novel bifunctionalthioureacatalyzed formal [5 + 1] cycloaddition of oxindoles and ester-linked bisenones was successfully developed. This strategy involves two sequential Michael additions, leading to spirooxindole δ-lactones with three contiguous stereocenters including an all-carbon quaternary center with high diastereo- and enantioselectivites. In addition, a remarkable N-substituent effect