Highly chemo- and stereoselective borrowing hydrogen processes are reported in which various target products are obtained through fine-tuning of the reaction conditions. By employing a robust Ru-catalyst of minimal stereogenicity, both kineticresolution and asymmetric induction were achieved simultaneously through a borrowing hydrogen cascade.
Phase-Transfer-Catalyzed Asymmetric Synthesis of Chiral<i>N</i>-Substituted Pyrazoles by Aza-Michael Reaction
作者:Su-Jeong Lee、Ju-Yeon Bae、Chang-Woo Cho
DOI:10.1002/ejoc.201500940
日期:2015.9
cinchona-based phase-transfer-catalyzed asymmetric aza-Michael reaction of pyrazole with various α,β-unsaturated ketones has been developed for the preparation of chiral N-substituted pyrazoles. This reaction provided the desired products in good yields (up to 99 %) with excellent enantioselectivities (87–94 % ee). In addition, the reaction of 3-methyl-1H-pyrazole, an unsymmetrically substituted pyrazole
Synthesis of a pyrenophorin precursor, 7-hydroxy-4-oxo-2-octenoic acid by the direct palladium catalyzed coupling of an acrylic tin reagent with an acid chloride
作者:Jeff W. Labadie、J.K. Stille
DOI:10.1016/s0040-4039(00)88321-5
日期:1983.1
A palladium catalyzed coupling reaction of an organotin reagent bearing acrylate functionality with an acidchloride serves as a method to introduce both a ketone and an acrylate functionality into a carbon framework; thus the coupling reaction of 4-t-butyldiphenylsiloxypentanoyl chloride with benzyl 3-tributylstannylacrylate gave a 71% yield of benzyl 7-t-butyldiphenylsiloxy-4-oxo-2-octenoate, which