Asymmetric Synthesis of α-Amino Acids: Preparation and Alkylation of Monocyclic Iminolactones Derived from α-Methyl <i>trans</i>-Cinnamaldehyde
作者:Ta-Jung Lu、Cheng-Kun Lin
DOI:10.1021/jo801514g
日期:2008.12.19
monocyclic iminolactones 14a and 14b have been prepared. The chiral auxiliary 12 was obtained from alpha-methyl-trans-cinnamaldehyde through reduction, methylation, Sharpless asymmetric dihydroxylation, and oxidation in 87% overall yield. Esterification of compound 12 with the respective protected aminoacids followed by deprotection and cyclization provided the corresponding iminolactones, each in 82%
A Modified System for the Synthesis of Enantioenriched
<i>N</i>
‐Arylamines through Copper‐Catalyzed Hydroamination
作者:Saki Ichikawa、Shaolin Zhu、Stephen L. Buchwald
DOI:10.1002/anie.201803026
日期:2018.7.9
Despite significant recent progress in copper‐catalyzed enantioselective hydroamination chemistry, the synthesis of chiral N‐arylamines, which are frequently found in natural products and pharmaceuticals, has not been realized. Initial experiments with N‐arylhydroxylamine ester electrophiles were unsuccessful and, instead, their reduction in the presence of copper hydride (CuH) catalysts was observed
New Method for Oxidative Carbon-carbon Bond Formation by the Reaction of Allyl Ethers, 2,3-Dichloro-5,6-dicyano-<i>p</i>-benzoquinone(DDQ) and Silyl Carbon Nucleophiles
作者:Yujiro Hayashi、Teruaki Mukaiyama
DOI:10.1246/cl.1987.1811
日期:1987.9.5
Allylethers are oxidized by DDQ to generate the corresponding cationic species, which in turn react with silyl carbon nucleophiles in the presence of a catalytic amount of lithium perchlorate to afford the coupled products in a one-pot procedure in good yields.
A facile TfOH-catalyzed oxidative cyclization of allyl compounds and isocyanide has been developed with the assistance of DDQ, where isocyanide is used as the crucial "N" and "CN" sources. Highly functionalized 2-cyanopyrroles are constructed efficiently through a new formal [3 + 2] mode, demonstrating diverse reactivity and synthetic utility in organic chemistry. 2-Cyanopyrrole is converted into a