TY - JOUR

T1 - Anion-Controlled Regioselectivity in Halonium-Mediated Arylations: A Kinetic and Mechanistic Study

AU - Ильин, Михаил Вячеславович

AU - Болотин, Дмитрий Сергеевич

AU - Сафинская, Яна Валерьевна

AU - Сысоева, Александра Александровна

AU - Новиков, Александр Сергеевич

PY - 2025/8/29

Y1 - 2025/8/29

N2 - Hypervalent halonium salts are versatile arylating agents. While the reactivity of iodonium salts is well-studied, the reactivity of bromonium and chloronium salts remains underexplored. Here, we investigate the interplay between σ-hole coordination and aryl transfer in cyclic chloronium and bromonium salts, demonstrating how external anions modulate their reactivity and the regioselectivity of their transformations. Kinetic studies reveal that fluoride and chloride additives activate chloronium and bromonium salts. DFT calculations support a concerted nucleophilic substitution mechanism, where anion coordination influences transition-state energetics. Notably, fluoride anions completely invert selectivity in chloronium-mediated arylations, favoring meta-substitution via a proposed aryne intermediate. These findings expand the synthetic utility of halonium salts, offering new strategies for regiocontrolled functionalization.

AB - Hypervalent halonium salts are versatile arylating agents. While the reactivity of iodonium salts is well-studied, the reactivity of bromonium and chloronium salts remains underexplored. Here, we investigate the interplay between σ-hole coordination and aryl transfer in cyclic chloronium and bromonium salts, demonstrating how external anions modulate their reactivity and the regioselectivity of their transformations. Kinetic studies reveal that fluoride and chloride additives activate chloronium and bromonium salts. DFT calculations support a concerted nucleophilic substitution mechanism, where anion coordination influences transition-state energetics. Notably, fluoride anions completely invert selectivity in chloronium-mediated arylations, favoring meta-substitution via a proposed aryne intermediate. These findings expand the synthetic utility of halonium salts, offering new strategies for regiocontrolled functionalization.

UR - https://pubs.acs.org/doi/full/10.1021/acs.joc.5c00805

UR - https://www.mendeley.com/catalogue/10cca7e3-c68d-3b01-89f4-f46048dd71b5/

U2 - 10.1021/acs.joc.5c00805

DO - 10.1021/acs.joc.5c00805

M3 - Article

VL - 90

SP - 12080

EP - 12087

JO - Journal of Organic Chemistry

JF - Journal of Organic Chemistry

SN - 0022-3263

IS - 34

ER -