下垣 実央

Abstract Tetrathia[8]circulene is a heteroaromatic framework consisting of an eight‐membered ring fused with four thiophene and four benzene units, whose electronic properties are highly tunable by peripheral substituents. Herein, we report the synthesis of a perfluorinated tetrathia[8]circulene bearing hexafluorocyclopentene rings via sequential Suzuki–Miyaura and C─H/C─Cl coupling reactions. Single‐crystal X‐ray diffraction analysis revealed a highly planar π‐conjugated core with dense F···F contacts, leading to a two‐dimensional layered and one‐dimensional columnar packing structure. UV–vis absorption spectroscopy and cyclic voltammetry demonstrated that the electron‐withdrawing hexafluorocyclopentene units substantially lower the LUMO energy level, resulting in a reduced HOMO–LUMO gap and enhanced electron‐accepting character. Density functional theory calculations further supported these findings by correlating the perfluoroalkyl annulation with frontier orbital stabilization and excited‐state properties.

Three contiguous stereocenters were constructed by an amino acid-catalyzed asymmetric aldol reaction of α-siloxyketones with racemizable α-haloaldehydes via dynamic kinetic resolution. One-pot catalytic asymmetric synthesis of the highly functionalized products...

Chiral tandem modifiers linking two or three cinchonidine molecules at the 2′-position of the quinoline ring are highly effective at low concentrations for the enantioselective hydrogenation of PCA over Pd/C.