Enantioselective Friedel–Crafts reactions between phenols and N-tosylaldimines catalyzed by a leucine-derived bifunctional catalyst
作者:Guo-Xing Li、Jin Qu
DOI:10.1039/c2cc31735d
日期:——
Enantioselective FriedelâCrafts reactions between phenols and N-tosylaldimines were developed using a bifunctional catalyst readily prepared from L-leucine. The chiral benzylic amine products were obtained in high yields (up to 96% yield) and good to high enantiomeric excesses (up to 95% ee).
N-Heterocyclic carbene-catalyzed [3+3] cyclocondensation of bromoenals with aldimines: highly enantioselective synthesis of dihydropyridinones
作者:Zhong-Hua Gao、Xiang-Yu Chen、Han-Ming Zhang、Song Ye
DOI:10.1039/c5cc04593b
日期:——
The N-heterocycliccarbene-catalyzed [3+3] cyclocondensation of bromoenals with aldimines was developed to give the corresponding dihydropyridinones in good yields with excellent enantioselectivies.
Triiodide-Mediated δ-Amination of Secondary C−H Bonds
作者:Ethan A. Wappes、Stacy C. Fosu、Trevor C. Chopko、David A. Nagib
DOI:10.1002/anie.201604704
日期:2016.8.16
amination of unactivated, secondary C−Hbonds to form a broad range of functionalized pyrrolidines has been developed by a triiodide (I3−)‐mediated strategy. By in situ 1) oxidation of sodium iodide and 2) sequestration of the transiently generated iodine (I2) as I3−, this approach precludes undesired I2‐mediated decomposition which can otherwise limit synthetic utility to only weak C(sp3)−H bonds. The mechanism
method for the efficient syntheses of optically active 1-alkyl homoallylic amines in yields up to 95%, 13.5:1 dr, and 98% ee under mild, aqueous reaction conditions, via the Rh-catalyzed asymmetric allylation of aliphatic aldimines. This method provides a streamlined synthetic platform for the preparation of indolizidine and piperidine alkaloids, thus demonstrating its usefulness.
Asymmetric Friedel−Crafts Reaction of Indoles with Imines by an Organic Catalyst
作者:Yong-Qiang Wang、Jun Song、Ran Hong、Hongming Li、Li Deng
DOI:10.1021/ja062700v
日期:2006.6.1
In this communication, we report an asymmetric Friedel-Craftsreaction of indoles with imines catalyzed by a bifunctional cinchona alkaloid catalyst. This is the first efficient organocatalytic asymmetric Friedel-Craftsreaction of indoles with imines. This reaction is operationally simple and, unprecedentedly, affords high enantioselectivity for a wide range of indoles and both aryl and alkyl imines