Asymmetric Hydrogenation of Ketones and Enones with Chiral Lewis Base Derived Frustrated Lewis Pairs
作者:Bochao Gao、Xiangqing Feng、Wei Meng、Haifeng Du
DOI:10.1002/anie.201914568
日期:2020.3.9
The concept of frustratedLewispairs (FLPs) has been widely applied in various research areas, and metal-free hydrogenation undoubtedly belongs to the most significant and successful ones. In the past decade, great efforts have been devoted to the synthesis of chiral boron Lewis acids. In a sharp contrast, chiral Lewisbase derived FLPs have rarely been disclosed for the asymmetric hydrogenation.
Development of inhibitors to antagonize the activities of antiapoptoticBcl-2familyproteins is of particular interest in cancer chemotherapy. We discovered a quinazoline-2(1H)-thione derivative (DCBL55) as a new Bcl-xL, Bcl-2, and Mcl-1 inhibitor by virtual database screening. We systematically modified the structure of compound 1 by chemical synthesis. The interactions of the compounds with Bcl-xL
An in situ formed porphyrin-inspired iron complex that catalyzesasymmetricepoxidation of di- and trisubstituted enones is described. The reaction provides highly enantioenriched α,β-epoxyketones (up to 99% ee). The practical utility of the new catalyst system is demonstrated by the gram-scale synthesis of optically pure epoxide. Hammett analysis suggests that the transition state of the reaction
Gerinnungsphysiologische Aktivität von 2-Aryl-2,3,4,5-tetrahydro-1H-benzocyclohepten-1,3-dionen
作者:Klaus Rehse、Thomas Lang、Norbert Rietbrock
DOI:10.1002/ardp.19773101206
日期:——
14 Titelverbindungen wurden synthetisiert. Neun zeigten nach einmaliger oraler Applikation bei Ratten blutgerinnungshemmende Eigenschaften. Fünf verringerten die Gerinnungsfähigkeit des Blutes (Quick‐Zeit) auf weniger als 25% der Norm. Bei 4i (340 mg/kg) wurde dieses Niveau nach 5 h erreicht und 50 h lang aufrechterhalten. Die maximale Verlängerung der Quick‐Zeit wurde hier nach 24 h beobachtet.