Catalytic Strategies for the Asymmetric Construction of Cyclic Frameworks with a Halogenated Tetrasubstituted Stereocenter

Abstract

The efficient and enantioselective construction of cyclic compounds with a halogenated tetrasubstituted carbon through various catalytic strategies remains challenging. Thus, research on modern asymmetric catalysis is important. In this review, recent achievements that streamlined the synthesis of halogenated cyclic molecules through organocatalysis or transition-metal catalysis were introduced. 2.7. Chiral Boron Catalysis 2.8. Chiral Brønsted Acid Catalysis 2.9. Chiral Iodoarene Catalysis 2.10.

Recent Advances in Catalytic Asymmetric Syntheses of Functionalized Heterocycles via Halogenation/Chalcogenation of Carbon‐Carbon Unsaturated Bonds

“…Very recently, the group of Denmark reported catalyst 18 catalyzed enantioselective cascade-type sulfenocyclization of alkyl-tethered alcohol to afford [6,6]spiroketals in good yields (35-89%) and excellent enantioselectivities (70-98%) (Scheme 30). [47] In this process, catalyst 18 serves as a chiral Lewis base with an electrophilic sulfur source to deliver enantioenriched thiiranium ion with alkenes.…”

“…[5] In the past decade, the asymmetric versions of halofunctionalizations have become a hot topic in organic chemistry and significant advances in this nascent field have been achieved. [6] In general, asymmetric halocyclization reactions involve concomitant processes of stereocontrolled vicinal halo-carbon and heteroatom-carbon bonds formation. [7] This stepwise pathway refers to the initial formation of a bridged haliranium ion intermediate and subsequent anti-attack of the haliranium ion by the nucleophile to form exclusively anti-products through an S N 2 mechanism.…”

Recent Developments in Enantioselective Organocatalytic Cascade Reactions for the Construction of Halogenated Ring Systems

“…The literature on reactions leading to compounds bearing chiral halogen‐containing centers has been reviewed periodically [32–35] . In 2020 Li and coworkers surveyed the literature available on methods for the asymmetric construction of cyclic molecules, involving both organocatalysis and metal‐catalyzed processes, but concentrated exclusively on those containing a halogenated tetrasubstituted stereocenter, [34a] while China, Dohi and coworkers surveyed in the same year cyclization reactions, asymmetric or not, induced by a halogen [34b] . A few enantioselective halolactonizations were described, besides some racemic cascade processes.…”

Stereoselective α-Chlorination of β-Keto Esters in the Presence of Hybrid Amide-Based Cinchona Alkaloids as Catalysts

“…The challenge of stereoselectively introducing a halogen atom into organic compounds has become one of the forefront research issues in organic chemistry in recent years . The diverse pharmaceutical activity of optically active halogen-containing molecules, as well as their ability to undergo further stereoselective modifications, plays a key role in modern organic synthesis and, consequently, in the design of drug targets. , Halogenated molecules often display distinct characteristics compared to their parent compounds, owing to the unique hydrophobic, space-filling, and electronic properties of the halogen atom .…”