4593-90-2Relevant articles and documents
Asymmetric conjugate addition reaction using pyrazole derivatives as a chiral catalyst
Kashima, Choji,Yokoyama, Hiroyo,Shibata, Saori,Fujisawa, Kiyoshi,Nishio, Takehiko
, p. 717 - 719 (2003)
The conjugate addition of Grignard reagent (2) onto 1-(α,β -unsaturated)acyl 3,5-dimethylpyrazole (1) was enantioselectively catalyzed by the copper complex from cuprous compounds and 3-phenyl-l-menthopyrazole (3).
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Stewart,Lipkin
, p. 3297 Anm. 2 (1939)
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Lipkin,Stewart
, p. 3295 (1939)
Photoredox Activation of Formate Salts: Hydrocarboxylation of Alkenes via Carboxyl Group Transfer
Huang, Yan,Hou, Jing,Zhan, Le-Wu,Zhang, Qian,Tang, Wan-Ying,Li, Bin-Dong
, p. 15004 - 15012 (2021/12/14)
A photoredox activation mode of formate salts for carboxylation was developed. Using a formate salt as the reductant, carbonyl source, and hydrogen atom transfer reagent, a wide range of alkenes can be converted into acid products via a carboxyl group tra
Asymmetric conjugate addition reactions with chiral oxadiazinones: Unusual conformational properties of the oxadiazinones
Obe, Fatima Olayemi,Davis, Ryan A.,Spurlock, Jennifer,Grunloh Barnes, Morgan M.,Lindvall, Tyler,Wendorf, Micah S.,Delach, Christina,Ferrence, Gregory M.,Standard, Jean M.,Hitchcock, Shawn R.
, (2021/02/26)
A series of Ephedra based oxadiazinones have been prepared, acylated, and examined in the asymmetric conjugate addition reaction with Grignard reagents in the presence of copper(I) bromide-dimethyl sulfide complex. The highest diastereoselectivity that was obtained in the conjugate addition reaction was observed with the (1R,2S)-ephedrine based N4-methyloxadiazinone (5:1 d.r.) favoring the formation of the (S)-configuration of the conjugate addition product. Efforts to enhance the level of diastereoselection via increasing the steric volume of the stereo-directing N4-substituent of the oxadiazinone (N4- = p-methoxyphenyl or -isopropyl) led to an observed decrease in the level of diastereoselection. A computational study was conducted to examine the conformations adopted by the N4-methyloxadiazinone vs. the N4-isopropyl-oxadiazinone that yielded the lower diastereoselectivity. An argument is made for the stereoelectronic properties of the N4-substituent being the cause of both the moderate diastereoselectivity and the unexpected facial preference for the conjugate addition.