Asymmetric Construction of a SeCF₃-Substituted Stereocenter by CuH-Catalyzed Hydroboration of 1-SeCF₃-Alkenes

Organic Letters, Год журнала: 2025, Номер unknown

Опубликована: Фев. 20, 2025

A copper hydride (CuH)-catalyzed regio- and enantioselective hydroboration of 1-trifluoromethylseleno (SeCF3)-alkenes with H-Bpin has been developed. The hydrocupration an in situ generated CuH species is followed by a boration reaction to successfully construct SeCF3- Bpin-substituted chiral carbon center. key success the appropriate choice tBu-modified biphosphine ligands, which enables overwhelming high efficiency.

Язык: Английский

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Ligand-Controlled Enantioselective Copper-Catalyzed Hydroboration and Ring-Opening Dihydroboration of Arylidenecyclobutanes

Journal of the American Chemical Society, Год журнала: 2025, Номер unknown

Опубликована: Март 25, 2025

Arylidenecyclobutanes are readily accessible and versatile reagents in synthetic chemistry due to the multifaceted reactivity exhibited by their alkene strained cyclobutane moieties. However, metal-catalyzed enantioselective functionalization of arylidenecyclobutanes, particularly controllable ring-retaining ring-opening reactions, is rarely explored. Considering utility enantioenriched organoboronate compounds, herein we report ligand-controlled copper-catalyzed hydroboration dihydroboration reactions arylidenecyclobutanes that afford chiral α-cyclobutyl benzylboronate 1,5-diboronate compounds with high enantioselectivity when (S)-DTBM-Segphos (S,S)-Ph-BPE employed, respectively. Mechanistic studies reveal process via β-C elimination significantly slower than arylidenecyclopropanes presence CuOAc (S,S)-Ph-BPE. The these two protocols further demonstrated through conducting various stereospecific site-selective transformations organoboron products, including concise synthesis bioactive molecules.

Язык: Английский

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Mechanistic Insights into Molecular Copper Hydride Catalysis: the Kinetic Stability of CuH Monomers toward Aggregation is a Critical Parameter for Catalyst Performance

Journal of the American Chemical Society, Год журнала: 2025, Номер unknown

Опубликована: Март 31, 2025

The activity of molecular copper hydride (CuH) complexes toward the selective insertion unsaturated hydrocarbons under mild conditions has contributed significantly to versatile methodologies for upgrading these feedstocks. However, catalysts are particularly susceptible deleterious aggregation, leading depletion active CuH species. Little is known about mechanisms how it influences overall catalyst performance, and can be controlled. We address challenges with mechanistic studies on a model reaction unactivated alkene hydroboration catalyzed by (IPr*CPh3)CuH (LCuH). report comprehensive investigation this system, identifying an aggregation pathway that continuously depletes catalytically LCuH form inactive clusters during turnover. Deactivation controlled primarily competition between kinetics initial dimerization step into LCuH. therefore propose understanding performance must account step, revising previously explored thermodynamic where concentration species equilibria established monomers. With series (NHC)CuH congeners (NHC = N-heterocyclic carbene), we demonstrate ostensibly minor structural modifications ligand peripheries drastically affect kinetics, while maintaining reactivity on-cycle insertion. employed computational approach based dynamics simulations provide in-depth specific substantially increase kinetic stability monomeric catalysts. Our combined experimental suggest strategies rational design broadly applied systems deactivation via pathways.

Язык: Английский

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Relay C(sp3)-H bond trifluoromethylthiolation and amidation by visible light photoredox catalysis

Science China Chemistry, Год журнала: 2024, Номер 67(11), С. 3844 - 3850

Опубликована: Окт. 12, 2024

Язык: Английский

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