Premium
A Single Bioinspired Hexameric Nickel Catechol–Alloxazine Catalyst Combines Metal and Radical Mechanisms for Alkene Hydrosilylation
Author(s) -
Das Agnideep,
Schleinitz Jules,
Karmazin Lydia,
Vincent Bruno,
Le Breton Nolwenn,
Rogez Guillaume,
Guenet Aurélie,
Choua Sylvie,
Grimaud Laurence,
DesageEl Murr Marine
Publication year - 2022
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.202200596
Subject(s) - hydrosilylation , chemistry , catalysis , nickel , hydride , radical , alkene , isomerization , photochemistry , ligand (biochemistry) , reductive elimination , metal , combinatorial chemistry , organic chemistry , biochemistry , receptor
Mechanisms combining organic radicals and metallic intermediates hold strong potential in homogeneous catalysis. Such activation modes require careful optimization of two interconnected processes: one for the generation of radicals and one for their productive integration towards the final product. We report that a bioinspired polymetallic nickel complex can combine ligand‐ and metal‐centered reactivities to perform fast hydrosilylation of alkenes under mild conditions through an unusual dual radical‐ and metal‐based mechanism. This earth‐abundant polymetallic complex incorporating a catechol‐alloxazine motif as redox‐active ligand operates at low catalyst loading (0.25 mol%) and generates silyl radicals and a nickel‐hydride intermediate through a hydrogen atom transfer (HAT) step. Evidence of an isomerization sequence enabling terminal hydrosilylation of internal alkenes points towards the involvement of the nickel‐hydride species in chain walking. This single catalyst promotes a hybrid pathway by combining synergistically ligand and metal participation in both inner‐ and outer‐ sphere processes.