Noncovalent interaction-driven regio- and enantioselective hydroalkynylation of unactivated alkenes to access remote
Fanling Meng1, Xian He2, Rui He1
1Tianjin Key Laboratory of Structure and Performance for Functional Molecules, College of Chemistry, Tianjin Normal University, Tianjin 300387, P. R. China.
Abstract:
Unactivated alkenes represent a challenging substrate for selective functionalization, particularly in achieving both regioselectivity and enantioselectivity. In this study, we present a strategy for the regio- and enantioselective hydroalkynylation of unactivated alkenes through the integration of noncovalent π⋯π interactions between the cyano group of the substrate and a chiral bis(oxazoline) ligand. The weak π⋯π interaction was supported by control experiments and computational studies. The method provides a reliable approach for synthesizing chiral nitriles with remote (β-, γ-, and δ-) stereocenters, which exhibit orthogonal reactivities and serve as valuable intermediates for further derivatization into otherwise difficult-to-access compounds. Our work provides a strategy for olefin functionalization and opens up avenues for the selective synthesis of chiral nitriles with remote stereocenters.
Related Concept Videos
02:17Regioselectivity of Electrophilic Additions to Alkenes: Markovnikov's Rule
The hydrohalogenation of an unsymmetrical alkene can yield two haloalkane products, depending on which vinylic carbon takes up the halogen. However, one product usually predominates, where hydrogen adds to the vinylic carbon bearing the...
02:34Regioselectivity and Stereochemistry of Acid-Catalyzed Hydration
02:36Regioselectivity and Stereochemistry of Hydroboration
Hydroboration proceeds in a concerted fashion with the attack of borane on the π bond, giving a cyclic four-centered transition state. The –BH2 group is bonded to the less substituted carbon and –H to the more substituted carbon. The concerted nature requires the simultaneous addition of –H and –BH2 across the same face of the alkene giving syn stereochemistry.
02:17Reduction of Alkenes: Asymmetric Catalytic Hydrogenation
The metal catalyst used can be either heterogeneous or homogeneous. When hydrogenation of an alkene generates a chiral center, a pair of enantiomeric products is expected to form. However, an enantiomeric excess of one of the products can be facilitated using an enantioselective reaction or an...
01:25Radical Anti-Markovnikov Addition to Alkenes: Overview
01:10α-Alkylation of Ketones via Enolate Ions