Rh-catalyzed asymmetric hydrogenation of 2-substituted 4H-thiochromenes and 4H-chromenes was successfully developed. This method provided highly efficient access to a series of chiral 2-substituted thiochromanes and chromanes in high yields with excellent enantioselectivities (up to 99% yield, 86–99% ee). The obtained chiral 2-substituted thiochromane products were also successfully transformed to
Structure−Activity Relationships and Molecular Modeling Analysis of Flavonoids Binding to the Benzodiazepine Site of the Rat Brain GABA<sub>A</sub> Receptor Complex
The affinities for the benzodiazepine binding site of the GABA(A) receptor of 21 flavonoids have been studied using [(3)H]flumazenil binding to rat cortical membranes in vitro. We show that flavonoids with high affinity for the benzodiazepinereceptor in vitro spanning the whole efficacy range from agonists (1q) to inverse agonists (1l) can be synthesized. The receptor binding properties of the flavonoids