Dynamic Kinetic Resolution of Azlactones by a Chiral <i>N</i>,<i>N</i>-Dimethyl-4-aminopyridine Derivative Containing a 1,1′-Binaphthyl Unit: Importance of Amide Groups
作者:Hiroki Mandai、Kohei Hongo、Takuma Fujiwara、Kazuki Fujii、Koichi Mitsudo、Seiji Suga
DOI:10.1021/acs.orglett.8b01960
日期:2018.8.17
resolution (DKR) of azlactones in the presence of benzoic acid and a binaphthyl-based N,N-4-dimethylaminopyridine (DMAP) derivative 1i having two amide groups at the 3,3′-positions of a binaphthyl unit is developed. The reaction proceeded smoothly with a wide range of azlactones to provide α-amino acid derivatives with good to high enantiomeric ratios (er’s). A multigram-scale reaction (2.5 g) for the
Resolution of racemic carboxylic acid derivatives by Ti-TADDOLate mediated esterification reactions—A general method for the preparation of enantiopure compounds
作者:Dieter Seebach、Georg Jaeschke、Konstanze Gottwald、Keiji Matsuda、Roberto Formisano、David A Chaplin、Matthias Breuning、Gerhard Bringmann
DOI:10.1016/s0040-4020(97)00456-0
日期:1997.6
transfer of an alkoxide ligand from the chiral ligand sphere of Ti-TADDOLates 1 to cyclic carboxylic acidderivatives is described. The kineticresolution of dioxolanones, azlactones and biaryl lactones by the Ti-TADDOLates affords, after recrystallization, ester products in highly enantioenriched form (er ≥ 97:3). The enantiomer-differentiating ring-opening of a chiral cyclic anhydride by a Ti-TADDOLate
Chemoenzymatic synthesis of a novel ligand for rhodium-catalysed asymmetric hydrogenation
作者:Brian Adger、Ulrich Berens、Matthew J. Griffiths、Michael J.K elly、Ray McCague、John A. Miller、Christopher F. Palmer、Stanley M. Roberts、Rüdiger Selke、Ute Vitinius、Guy Ward
DOI:10.1039/a704136e
日期:——
The hydrogenation of alkenes 7a–g using a chiral rhodium catalyst
6 (based on a bicyclo[3.2.0]heptane framework) takes place to give the
phenylalanine derivatives 8a–g with remarkably high
stereoselectivity (59–92% ee).