Cobalt Nanoparticles Formed upon Reaction of Cp*Co(III) Metallacycles with Na[BHEt3] Show Catalytic Activity in the Hydrosilylation of Aryl Ketones, Aldehydes and Nitriles. Issue 6 (21st December 2022)

• Record Type: Journal Article
• Authors: Antuña‐Hörlein, Carmen; Wu, Fule; Deraedt, Christophe; Bouillet, Corinne; Djukic, Jean‐Pierre
• Is Part Of: European journal of inorganic chemistry. Volume 26:Issue 6(2023)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-12-21
• Subjects: Cobalt -- Hydrosilylation -- Homogeneous catalysis -- Metallacycle -- Nanoparticles; Chemistry, Inorganic -- Periodicals; Organometallic chemistry -- Periodicals; Bioinorganic chemistry -- Periodicals; Solid state chemistry -- Periodicals; 546
• DOI: 10.1002/ejic.202200563
• Languages: English
• ISSNs: 1434-1948

Abstract

Abstract: The reactivity of the 2‐phenylpyridine‐derived [Cp*CoI(phpy‐ κ C, N )] metallacycle towards Et3 SiH and hydrides was evaluated. The treatment of the same Co(III) complex with Na[BHEt3 ] resulted in its decomposition into cobalt nanoparticles. The hydride‐promoted decomposition of the metallacycle involves the transient formation of an elusive hydrido‐cobalt(III) intermediate, the traces of which were detected by 1 H NMR spectroscopy at sub‐ambient temperature. The Co nanoparticles produced from a 5 mol% and 10 mol% load of cobaltacycle and Na[BHEt3 ] respectively contain Co(0) that is responsible for the hydrosilylation by Et3 SiH of arylketones into silylalkyl ethers. To minimize the residual side reduction of carbonyls by Na[BHEt3 ], a mixture of 5 mol% of the latter with 5 mol% of BEt3 was found to produce optimal hydrosilylation yields at 40 °C in 2 h. Under similar conditions, several arylnitriles were mono‐hydrosilylated into N‐silyl‐imines in yields ranging from 68 to 100 %. Abstract : The treatment of a cobaltacycle with Na[BHEt3 ] produces Co nanoparticles that are active as catalyst for the hydrosilylation of aromatic aldehydes, ketones and nitriles.