Coplanar Atropochiral 5H-Cyclopenta[2,1-b:3,4-b']dipyridine Ligands: Synthesis and Applications in Asymmetric
Han Yang1, Xiaojie Sun1, Zhen Chen1
1Hefei National Research Center for Physical Sciences at the Microscale, Department of Chemistry, University of Science and Technology of China, 96 Jinzhai Road, Hefei, Anhui, 230026, P. R. China.
Abstract:
Bipyridines represent a class of ligands renowned for their versatility and efficacy in numerous transition metal-catalyzed reactions. Chiral bipyridine ligands are noted for their distinctive reactivity and stereoselectivity. In this work, we have designed and synthesized a class of bipyridine ligands endowed with an axially chiral scaffold. These ligands feature: (a) a precisely aligned coplanar bipyridine framework that is beneficial for metal chelation; (b) a spacious environment around the metal-bipyridine complexes, capable of hosting substrates with substantial steric bulk; (c) a chiral pocket induced by the axially chiral architecture. These atropochiral planar bipyridine ligands were successfully applied in copper-catalyzed ring-opening reactions of cyclic diaryliodoniums with bulky secondary amines, achieving high efficiency and stereoselectivity that were unsuccessful in our previous efforts.
More Related Videos
Related Concept Videos
Diels–Alder Reaction Forming Cyclic Products: Stereochemistry
[4+2] Cycloaddition of Conjugated Dienes: Diels–Alder Reaction
Cycloaddition Reactions: Overview
[3,3] Sigmatropic Rearrangement of 1,5-Dienes: Cope Rearrangement
Diels–Alder Reaction Forming Bridged Bicyclic Products: Stereochemistry
Thermal Electrocyclic Reactions: Stereochemistry
Selection Rules: Thermal Activation
Conjugated systems containing an even number of π-electron pairs undergo a conrotatory ring closure. For example, thermal electrocyclization of (2E,4E)-2,4-hexadiene, a conjugated diene containing two π-electron pairs, gives trans-3,4-dimethylcyclobutene.


