Catalytic Reduction of Nitriles by Polymethylhydrosiloxane Using a Phenalenyl-Based Iron(III) Complex

Abstract

The reduction of nitriles to primary amines using an inexpensive silane such as polymethylhydrosiloxane (PMHS) is an industrially important reaction. Herein we report the synthesis of an earth-abundant Fe(III) complex bearing a phenalenyl-based ligand that was characterized by mass spectroscopy, elemental analysis, cyclic voltammetry, and single-crystal X-ray diffraction. The complex showed excellent catalytic activity toward reduction of aromatic, heteroaromatic, aliphatic, and sterically crowded nitriles to produce primary amines using polymethylhydrosiloxane (PMHS).

Phenalenyl Radical: Smallest Polycyclic Odd Alternant Hydrocarbon Present in the Graphene Sheet

“…In this approach, a PLY-based multidentate ligand was utilized. Such phenalenyl ligand, PLY­(O,N,N,O) ( L8 ) was used to prepare Fe and Mn based metal complexes (Scheme a). These metal complexes were utilized in the catalytic reduction of amides and nitriles.…”

Tandem Fe/Zn or Fe/In Catalysis for the Selective Synthesis of Primary and Secondary Amines via Selective Reduction of Primary Amides

“…Thus, the obtained nitrile 2 should then react with the hydrosilane to lead to the N ‐silylimine A , and the disilylated amine B , both Zn(OTf) 2 and In(OTf) 3 possibly playing a role in activating the amide moiety. Noticeably these two reactions did not proceed in the absence of light activation [18,20–22] . It should be underlined that benzonitrile 2 a was not reduced to the corresponding amine 3 a using either Zn(OTf) 2 or In(OTf) 3 as the sole catalyst.…”

“…Noticeably these two reactions did not proceed in the absence of light activation. [18,[20][21][22] It should be underlined that benzonitrile 2 a was not reduced to the corresponding amine 3 a using either Zn(OTf) 2 or In(OTf) 3 as the sole catalyst. (Scheme 4b) It should be underlined that there are only scarce reports dealing with zinc-catalyzed hydrosilylation of benzonitrile derivatives, and that only the formation of silylated imines was described when using well defined zinc hydride complexes.…”

“…of PhSiH 3 led exclusively to benzylamine 3 a with only trace amount of 4 a. (Scheme 4a) [21,22] Importantly, no reaction occurred without light activation. (Scheme 4a) This result with In(OTf) 3 as a co-catalyst thus excludes the formation of the secondary amine 4 through a pathway involving the generation of the aldimine C resulting of the condensation of A with B.…”

Designing a Redox Noninnocent Phenalenyl-Based Copper(II) Complex: An Autotandem Catalyst for the Selective Oxidation of Polycyclic Aromatic Hydrocarbons (PAHs)

“…14 Vijaykumar and co-workers have shown that the ligand-based "electron reservoir" in the PLY−nickel(II) complex can assist in catalytic anti-Markovnikov's hydrosilylation reactions. 6 In the recent past, redox participation of the PLY-based ligand LH 2 , (9,9′-(ethane-1,2-diylbis-(azanediyl))bis(1H-phenalen-1-one)), resulted in the development of an iron-based catalyst [Fe III (L)Cl] 15 and a chemoselective manganese-based catalyst [Mn III (L)Cl]. 16 In fact, the [Mn III (L)Cl] complex is the first catalyst reported in the literature to facilitate a controlled catalytic transformation of chemically inert primary amides into amines as well as nitriles by a slight modification of the reaction conditions.…”