Chiral Phosphoric Acid Catalyzed Enantioselective Desymmetrization of 1,4‐Dihydropyridines by C(sp<sup>3</sup>)−H Bromination
Min Han, Shiqi Zhang, Xin Cui, Qiwei Wang, Guangxun Li, Zhuo Tang
Abstract
Described herein is the enantioselective synthesis of Hantzsch-type 1,4-dihydropyridines (DHPs), which are frequently contained in pharmaceuticals. Readily available symmetrical 1,4-DHPs were used as substrates, and the methyl group at the 2- or 6-position of the 1,4-DHP was selectively monobrominated by desymmetrizing enantioselective bromination. The inert C-H bond was converted into a versatile C-Br bond, which guaranteed the modification of the chiral 1,4-DHP derivatives with high efficiency. Furthermore, axially chiral 4-aryl pyridines were accessible by central-to-axial chirality conversion.
Topics & Concepts
Enantioselective synthesisDesymmetrizationHalogenationChemistryAxial chiralityCatalysisChirality (physics)Organic chemistryStereochemistryMedicinal chemistryPhysicsQuarkChiral symmetry breakingNambu–Jona-Lasinio modelQuantum mechanicsAxial and Atropisomeric Chirality SynthesisAsymmetric Synthesis and Catalysis