<b>PQXdpap</b>: Helical Poly(quinoxaline-2,3-diyl)s Bearing 4-(Dipropylamino)pyridin-3-yl Pendants as Chirality-Switchable Nucleophilic Catalysts for the Kinetic Resolution of Secondary Alcohols
Helically chiral poly(quinoxaline-2,3-diyl)s bearing 4-(dipropylamino)pyridin-3-yl pendants at the 5-position of the quinoxaline ring (PQXdpap) exhibited high catalytic activities and moderate to high selectivities (up to s = 87) in the acylative kinetic resolution of secondary alcohols. The solvent-dependent helical chirality switching of PQXdpap between pure toluene and a 1:1 mixture of toluene and
Optically pure bulky (hetero)arylalkyl carbinols via kinetic resolution
作者:Bin Hu、Meng Meng、John S. Fossey、Weimin Mo、Xinquan Hu、Wei-Ping Deng
DOI:10.1039/c1cc14591f
日期:——
Planar chiral nucleophilic catalyst Fc-PIP was employed in the kineticresolution of bulky (hetero)arylalkyl carbinols delivering unreacted alcohols with extremely high enantiomeric excess (>99.0% ees) in ideal conversions ranging from 50.4-56.7%.
Chiral phosphoric acid catalyzed asymmetric transfer hydrogenation of bulky aryl ketones with ammonia borane
作者:Qiwen Zhou、Wei Meng、Xiangqing Feng、Haifeng Du、Jing Yang
DOI:10.1016/j.tetlet.2019.151394
日期:2020.1
An asymmetrictransferhydrogenation of bulky aryl ketones with ammonia borane was successfully realized with chiral phosphoric acid (CPA) as catalyst and water as additive. A variety of optically active secondary alcohols were obtained in good to high yields with up to 77% ee. The reaction likely proceeded through a Brønsted acid-promoted double-hydrogen transfer between ketones and ammonia borane
Benzotetramisole: A Remarkably Enantioselective Acyl Transfer Catalyst
作者:Vladimir B. Birman、Ximin Li
DOI:10.1021/ol060065s
日期:2006.3.1
A commercially available pharmaceutical, tetramisole, was found to be a competent enantioselective acylation catalyst. Its benzannellated analogue, benzotetramisole (BTM), produced outstanding enantioselectivities in kinetic resolution of secondary benzylic alcohols.