Proton-Modulated Nickel Hydride Electrocatalysis for the Hydrogenation of Unsaturated Bonds and Olefin Isomerization DOI
Song Xue,

Yuanqiong Huang,

Bei Zhao

et al.

Journal of the American Chemical Society, Journal Year: 2025, Volume and Issue: unknown

Published: April 21, 2025

Transition-metal hydrides stand as indispensable intermediates in both energy conversion and organic synthesis. Their electrochemical generation represents a compelling sustainable approach, enabling precise control over the reactivity expanding scope of electrocatalytic hydrogenation isomerization. However, major challenge Ni-catalyzed is competing hydrogen evolution reaction (HER), which has led to various innovative strategies aimed at circumventing Ni-H formation. Here, we pursued an alternative approach by designing bifunctional ligand with pendant amine moiety promote This design enabled selective (semi)hydrogenation diverse range substrates, including terminal internal alkynes, alkenes, aldehydes, achieving unprecedented substrate scope. Remarkably, also demonstrated tunable positional selectivity for olefin isomerization employing different types proton sources. Our method exhibits excellent functional group tolerance, streamlining access pharmaceuticals their derivatives. Computational studies revealed crucial, noninnocent role source modulating metal hydride selectivity, either through bonding, direct protonation amine, or facilitation protodemetalation.

Language: Английский

Nickel-Catalyzed Cross-Electrophile Coupling of Aryl Triflates with Alkyl Halides: Mechanism-Informed Design of More General Conditions DOI
Seoyoung Kim, Matthew J. Goldfogel, Benjamin N. Ahern

et al.

Journal of the American Chemical Society, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 10, 2025

Aryl triflates make up a class of aryl electrophiles that are available in single step from the corresponding phenol. Despite known reactivity nickel complexes for C-O bond activation phenol derivatives, nickel-catalyzed cross-electrophile coupling using has proven challenging. Herein, we report method to form C(sp2)-C(sp3) bonds by with alkyl bromides and chlorides phenanthroline (phen) or pyridine-2,6-bis(N-cyanocarboxamidine) (PyBCamCN)-ligated catalysts. The scope reaction is demonstrated 38 examples (61 ± 14% average yield). Mechanistic studies provide rationale conditions used roadmap further applications coupling. First, rate radical generation controlled maintaining majority halide as chloride, which unreactive, utilizing dynamic exchange process adjust concentration reactive bromide iodide. Second, challenge electron-rich appears be due off-cycle transmetalation unproductive zinc reagents. optimal PyBCamCN ligand together LiCl avoids this deleterious step.

Language: Английский

Citations

0
Electrochemical Nickel-Catalyzed C(sp2)-H Functionalization of Tropones with Aldehydes DOI Creative Commons
Andrea Brunetti, Sofia Kiriakidi,

Mauro Garbini

et al.

ACS Catalysis, Journal Year: 2025, Volume and Issue: unknown, P. 3184 - 3190

Published: Feb. 6, 2025

A direct electroreductive functionalization of tropones employing aldehydes as alkylating agents is reported. This C(sp2)-H process leverages the mediation electroactive nickel complexes, enabling a wide range both native and substituted (44 examples) to be alkylated selectively at α-position in high yields (up 90%). Combined electrochemical, spectroelectrochemical, computational analyses disclosed whole mechanistic pathway revealed key role played by reduced Ni complexes activating tropone core toward condensation with aldehydes.

Language: Английский

Citations

0
Proton-Modulated Nickel Hydride Electrocatalysis for the Hydrogenation of Unsaturated Bonds and Olefin Isomerization DOI
Song Xue,

Yuanqiong Huang,

Bei Zhao

et al.

Journal of the American Chemical Society, Journal Year: 2025, Volume and Issue: unknown

Published: April 21, 2025

Transition-metal hydrides stand as indispensable intermediates in both energy conversion and organic synthesis. Their electrochemical generation represents a compelling sustainable approach, enabling precise control over the reactivity expanding scope of electrocatalytic hydrogenation isomerization. However, major challenge Ni-catalyzed is competing hydrogen evolution reaction (HER), which has led to various innovative strategies aimed at circumventing Ni-H formation. Here, we pursued an alternative approach by designing bifunctional ligand with pendant amine moiety promote This design enabled selective (semi)hydrogenation diverse range substrates, including terminal internal alkynes, alkenes, aldehydes, achieving unprecedented substrate scope. Remarkably, also demonstrated tunable positional selectivity for olefin isomerization employing different types proton sources. Our method exhibits excellent functional group tolerance, streamlining access pharmaceuticals their derivatives. Computational studies revealed crucial, noninnocent role source modulating metal hydride selectivity, either through bonding, direct protonation amine, or facilitation protodemetalation.

Language: Английский

Citations

0