Phosphorus in organic synthesis—XI Amino acids and peptides—XXI
作者:T. Shioiri、Y. Yokoyama、Y. Kasai、S. Yamada
DOI:10.1016/0040-4020(76)85134-4
日期:——
Diethyl phosphorocyanidate(DEPC) reacts with carboxylic acids in the presence of triethylamine leading to transient formation of acyl cyanides, but in presence of alcohols or amines, carboxylic esters or amides are produced. DEPC is especially effective for the synthesis of amides and peptides, and showed a satisfactory result on the Young racemization test.
Photoredox Catalysis Enables Access to <i>N</i>-Functionalized 2,1-Borazaronaphthalenes
作者:Xie Wang、Geraint H. M. Davies、Adriel Koschitzky、Steven R. Wisniewski、Christopher B. Kelly、Gary A. Molander
DOI:10.1021/acs.orglett.9b00884
日期:2019.4.19
The synthesis and utilization of a class of 2,1-borazaronaphthyltrifluoroborate reagents that provide a general solution to the challenge of N-functionalization of the 2,1-borazaronaphthalene core is described. By adorning the nitrogen of this core with a trifluoroboratomethyl unit, a suite of odd-electron processes can be executed, installing motifs that would otherwise be inaccessible using a two-electron
Catalytic Asymmetric Propionate Aldol Reactions via Acyl Halide−Aldehyde Cyclocondensations
作者:Scott G. Nelson、Zhonghui Wan
DOI:10.1021/ol005968e
日期:2000.6.1
Catalyzedasymmetricacylhalide-aldehydecyclocondensation (AAC) reactions afford highly enantiomerically enriched 3,4-disubstituted-2-oxetanones. These reactions constitute catalyticasymmetric propionate aldol additions. An optically active Al(III)-triamine complex (10 mol %) catalyzes the di(isopropyl)ethylamine-mediated cyclocondensation of propionyl bromide and a variety of aldehydes to afford
Csp<sup>3</sup>–H monofluoroalkenylation <i>via</i> stereoselective C–F bond cleavage
作者:Ying Hu、Xingchen Liu、Zhouyang Ren、Binjing Hu、Jie Li
DOI:10.1039/d1cc06247f
日期:——
A practical nickel- and photoredox-catalyzed Csp3–H monofluoroalkenylation with gem-difluoroalkenes for the synthesis of stereodefined tetrasubstituted fluoroalkenes with complete control of stereoselectivity has been developed.
Method for racemization of optically active chrysanthemic acid or its derivatives
申请人:SUMITOMO CHEMICAL COMPANY, LIMITED
公开号:EP0299760A1
公开(公告)日:1989-01-18
Optically active chrysanthemic acid or its derivatives of the formula
(wherein X represents a hydroxyl group, a halogen atom, a C₁₋₂₀ alkoxy group or a 2,2-dimethyl-3-isobutenyl-cyclopropane carboxyl group and * mark shows asymmetric carbon atom) is racemized by allowing it to react with a bromine compound or a SH compound, in the presence of light.
光学活性菊酸或其衍生物,其式为
(其中 X 代表羟基、卤素原子、C₁₋₂₀烷氧基或 2,2-二甲基-3-异丁烯基环丙烷羧基,* 标记表示不对称碳原子)在光照下与溴化合物或 SH 化合物反应,使其发生外消旋化。