10.1002/cber.19961290103
The research focuses on the reaction of alkylzirconocene cation complexes with bis(alkynyl)silane reagents, aiming to prepare heterodimetallic compounds containing an alkynyl ligand bridge between zirconium and silicon. The study utilized methylzirconocene cation as the reagent, specifically the tetrahydrofuran-stabilized form [Cp2ZrCH3(THF)+BPh4], and a series of bis(alkynyl)silane reagents (R'C≡C)2SiR2, prepared by reacting alkynyl lithium reagents with Cl2SiR2. The reactions resulted in the formation of heterobimetallic four-membered ring systems, where the silicon and zirconium centers were connected by both an alkenyl and an alkynyl bridging ligand. The research concluded that the reaction pattern observed was typical when alkyl group 4 metallocene cation reagents and bis(alkynyl)silane derivatives are combined, leading to a stable cationic four-membered main group/transition metal dimetallic system that shows interesting o-alkynyl bridging. This finding is significant for understanding the behavior of alkyl zirconocene cations in reagents and catalysts.
10.1002/cssc.202000856
The research explores a novel method for synthesizing primary amines using an iron catalyst. The purpose of this study is to develop a sustainable and efficient process for the reductive amination of ketones and aldehydes using ammonia as the nucleophile, leveraging an earth-abundant metal catalyst. The researchers synthesized an iron catalyst by impregnating a specific Fe complex onto a nitrogen-doped silicon carbide (N-doped SiC) support, followed by pyrolysis and reduction steps. This catalyst demonstrated broad substrate scope, converting various ketones and aldehydes, including purely aliphatic, aryl-alkyl, dialkyl, and heterocyclic compounds, into their corresponding primary amines with good to excellent yields. The catalyst also tolerated multiple functional groups such as hydroxy, methoxy, dioxol, sulfonyl, and boronate esters. Key chemicals used in the research include the Fe complex (complex I), N-doped SiC as the support material, ammonia dissolved in water as the nitrogen source, and hydrogen gas. The study concludes that the developed iron catalyst is easy to handle, selective, reusable, and suitable for upscaling, making it a promising alternative to traditional noble metal catalysts for the synthesis of primary amines.