Sulfonic acid supported on hydroxyapatite-encapsulated-γ-Fe2O3 nanocrystallites as a magnetically separable catalyst for one-pot reductive amination of carbonyl compounds
2-Phenyliminomethylphenols, 2-phenylaminomethylphenols and their copper(II) complexes
作者:H.J. Harries、B.F. Orford、J. Burgess
DOI:10.1016/s0020-1693(00)88934-3
日期:1983.1
2-phenyliminomethylphenols (I) and 2-phenylaminomethylphenols (II) are described. Acid dissociation constants, determined potentiometrically, for the amines (II) are related to substituent constants; values are not obtained for Schiff bases(I) due to their hydrolysis. IR spectra of the amines (II) indicate chelate ring formation via OH⋯N hydrogen bonding. NMR spectra for Schiff bases (I) are consistent
作者:Shunxi Dong、Marcus Frings、Duo Zhang、Qianqian Guo、Constantin G. Daniliuc、Hanchao Cheng、Carsten Bolm
DOI:10.1002/chem.201703263
日期:2017.10.9
An N-heterocyclic carbene (NHC)-catalyzed highlydiastereo- and enantioselective formal [3+2] reaction of o-hydroxy aromatic aldimines and cinnamaldehydes leading to enantioenriched trans-γ-lactams was developed. Subsequent transformations allowed modifying the heterocyclic core of the products. An organocatalytic kinetic resolution of chiral lactams was demonstrated in a first proof-of-principle study
Catalytic Asymmetric Inverse-Electron-Demand (IED) [4+2] Cycloaddition of Salicylaldimines: Preparation of Optically Active 4-Aminobenzopyran Derivatives
The catalyticasymmetricinverse-electron-demand (IED) [4+2] cycloaddition of various salicylaldehyde-derived N-arylimines with electron-rich alkenes in the presence of chiral BINOL-derived phosphoric acid catalysts has been studied with the aim of obtaining opticallyactive4-aminobenzopyranderivatives. Dienophiles such as 2,3-dihydro-2H-furan, benzyl N-vinylcarbamate and 2-vinylindole have been
The reactions of salicylaldimines with electron‐rich alkenes (2,3‐dihydro‐2H‐furan and 3,4‐dihydro‐2H‐pyran) catalyzed by N,N′‐dioxide–Sc(OTf)3complexes were investigated. The methodology was successfully applied to the asymmetricsynthesis of cis‐4‐aminobenzopyran derivatives. Excellent yields, diastereo‐ and enantioselectivities were observed for a broad range of substrates under mild conditions
Brønsted acids of anionic chiral Co(<scp>iii</scp>) complexes as catalysts for the stereoselective synthesis of cis-4-aminofuranobenzopyrans
作者:Hua-Jie Jiang、Kun Liu、Jing Wang、Na Li、Jie Yu
DOI:10.1039/c7ob02452e
日期:——
A highly enantioselective interrupted Povarov reaction of salicylaldimines and 2,3-dihydrofuran was developed, through the elegant Brønsted acid catalysis of anionic chiral Co(III) complexes. This reaction affords the cis-4-aminofuranobenzopyran derivatives with up to 95% yield, >20:1 dr and 96:4 er. Moreover, a one-pot three-component procedure of salicylaldehydes, anilines, and 2,3-dihydrofuran proves