Visible-light photoredox catalyzed oxidative Strecker reaction

Abstract

An aerobic photocatalytic oxidative cyanation of tertiary amines providing valuable α-aminonitriles in good to excellent yields was developed. Mild reaction conditions and low catalyst loading are attractive features of the protocol.

PEGylated magnetic nanoparticles (PEG@Fe 3 O 4 ) as cost effective alternative for oxidative cyanation of tertiary amines via C H activation

“…So far a number of metal-based catalysts, such as Fe [26][27][28], Ru [29,30], V [31], Mo [32], Au [33] and Re [34] in the presence of oxidants such as molecular oxygen, hydrogen peroxide, tert-butyl hydroperoxide (TBHP) have been reported for the direct oxidative cyanation of tertiary amines. Photoredox catalysts mainly based on ruthenium have also been reported for the oxidative ␣-cyanation of sp 3 C H bonds of tertiary amines [35][36][37][38]. However, the use of expensive metals such as ruthenium, rhenium, multi-step as well as high cost synthesis of catalysts make these methods less desirable from environmental and economic points of view.…”

Sunlight assisted synthesis of α-aminonitrile using Capillary flow microreactor: A new approach

“…Amongst the various methods known for the synthesis is the oxidative cyanation of sp 3 CÀ ÀH adjacent to the nitrogen atom which represents one of the best approaches to prepare these compounds [7]. Earlier works showed the formation of reactive iminium ion intermediates by treating tertiary amines with various metal catalysts in the presence of stoichiometric amounts of oxygen which is intercepted with HCN to give the equivalent a-cyanation product [5].…”

“…a-Aminonitriles are known to be an essential category of so many intermediates for an extensive variety of biological products and pharmaceuticals since a-amino acids are produced from the hydrolysis of the nitrile function [5]. Also, the hydrogenation of nitriles yields useful 1,2-diamines.…”

“…Rueping et al [5] carried out this type of reaction using a cyclic amine, tetrahydroisoquinoline derivatives, an inorganic iridiumbased poly pyridyl complex [Ir(tbp-py) 2 (bpy)]PF 6 ] where "tbp-py" stands for 2-(4-tBu-phenyl)-pyridine, as a catalyst, acetic acid as a co-catalyst, and reaction was irradiated under 5 W fluorescent bulb. They were able to isolate the corresponding product with about 96% yield after 20 h of reaction.…”

α‐Cyanation of Aromatic Tertiary Amines using Ferricyanide as a Non‐Toxic Cyanide Source

“…[2] Another common approach for the synthesis of aamino nitriles is cross-dehydrogenative coupling (CDC) [3] in which tertiary amines are oxidized to the corresponding iminium ions in the presenceo fac yanide source. [4] Apart from homogeneous transition metal catalysts, [4d,5] photoredox systemss uch as RuCl 3 /O 2, [6] RuCl 3 /H 2 O 2, [7] [Ir(tbppy) 2 (bpy)]PF 6 /O 2 , [8] [Ru(bpy) 3 ]Cl 2 /BrCCl 3, [9] Pd(II) complexes, [10] or organogold species [11] have been shown to be efficient catalysts.F urthermore,h eterogeneous systems [12] have also been applied. While most of these procedures rely on the use of expensive transitionm etal catalysts, cheaper alternativess uch as TiO 2 /air, [13] organic dyes such as rose bengal [14] or eosin Y/air [15] have been reported as well.…”