Well‐Defined Cyclopentadienyl NHC Iron Complex as the Catalyst for Efficient Hydrosilylation of Amides to Amines and Nitriles

Abstract

International audienceIron comes first, second, and third: By using the well-defined Cp-IMes iron cationic complex ([Fe], see scheme) as the catalyst, an efficient and versatile hydrosilylation reduction reaction of secondary and tertiary amides is performed in solvent-free conditions at 100 °C under visible light irradiation for 16 h to give the corresponding amines in good yields. When the reaction is performed with primary amides, the corresponding nitrile derivatives are obtained

Direct Hydrosilylation of Tertiary Amides to Amines by an In Situ Formed Iron/N‐Heterocyclic Carbene Catalyst

“…Iron, being the most abundant transition metal and displaying low toxicity, is an interesting alternative for this transformation, and there are some [ recent examples on the use of iron catalysts for the reduction of amides under hydrosilylation conditions. [15] An efficient protocol for the reduction of primary amides to their corresponding amines was recently presented by Beller and co-workers. [11] Simultaneously, the group of Nagashima presented that the iron-carbonyl complexes [Fe(CO) 5 ] and [Fe 3 (CO) 12 ] efficiently catalyzed the same transformation.…”

Synthesis, reactivity, and some photochemistry of ortho-N,N-dimethylaminomethyl substituted aryl and ferrocenyl pentamethylcyclopentadienyl dicarbonyl iron complexes

“…More recently, efficient visible lightpromoted reduction of aldehydes, ketones, esters, imines and amides has been described by Darcel et al using NHC and phosphine complexes 3 and 4 as well as some of their derivatives. [25][26][27][28][29][30]. [33,34] despite the presence of the sterically demanding N-heterocyclic carbene-functionalized cyclopentadienyl ligand, while…”

Hydrosilylative Reduction of Tertiary Amides to Amines Catalyzed by N‐(Phosphinoaryl)anilido Complexes of Iron and Cobalt

“…In the context of amide hydrosilylation, early efforts towards this goal were reported concurrently by Beller and Nagashima, who demonstrated the utility of Fe carbonyl species in such catalysis under both thermal (6–30 mol % Fe, 100 °C, 24 h) and photochemical (10 mol % Fe, RT, 9 h) conditions. Since these initial reports, the groups of Sortais and Darcel, Buitrago and Adolfsson, and Driess have each reported on the utility of Fe complexes supported by N ‐heterocyclic carbene ligation for amide hydrosilylation catalysis. Although the natural abundance of Fe makes it the top choice amongst the transition metals from the perspective of sustainability, a handful of noteworthy examples of amide hydrosilylation mediated by other base metals, such as Mn‐, Co‐, and Ni‐, as well as Cu‐ and Zn‐based catalysts, have also been disclosed, and efforts to develop non‐metal catalysts have also been undertaken .…”