Redox-Neutral α-Cyanation of Amines

Abstract

α-Aminonitriles inaccessible by traditional Strecker chemistry are obtained in redox-neutral fashion by direct amine α-cyanation/N-alkylation or alternatively, α-aminonitrile isomerization. These unprecedented transformations are catalyzed by simple carboxylic acids.

Copper‐Catalyzed Regioselective Intramolecular Oxidative α‐Functionalization of Tertiary Amines: An Efficient Synthesis of Dihydro‐1,3‐Oxazines

“…The reaction of ketone 3 a with pyrrolidine to form 17, and eventually to produce 2 a by iminium rearrangment, was not observed under the reaction conditions (Scheme 5). [21] To gain more insight into the SET mechanism, the model reaction was performed in the presence of radical scavengers such as 2,6-di-tert-butyl-4-methyl phenol (BHT) and thiophenol (1 equiv of each). A significant drop in yield was observed and only a trace of product 2 a was isolated, thus suggesting that this reaction includes a radical process.…”

Copper‐Catalyzed Regioselective Intramolecular Oxidative α‐Functionalization of Tertiary Amines: An Efficient Synthesis of Dihydro‐1,3‐Oxazines

“…[21] To gain more insight into the SET mechanism, the model reaction was performed in the presence of radical scavengers such as 2,6-di-tert-butyl-4-methyl phenol (BHT) and thiophenol (1 equiv of each). Cu I would presumably be reoxidized to Cu II by atmospheric oxygen.…”

Ruthenium and Iron‐Catalysed Decarboxylative N‐alkylation of Cyclic α‐Amino Acids with Alcohols: Sustainable Routes to Pyrrolidine and Piperidine Derivatives

“…A preliminary proposal for the formation of these regioisomers is provided (Supporting Information, Figure S5, Note 1). Basic DL ‐proline, used in slight excess in the system, is assumed to play a role in α‐aminonitrile isomerization in favour of regioisomer 5 (Supporting Information, Figure S5, Note 1) . This is supported by the fact that 5:5′ ratios followed a specific trend (Table ) related to the nature of the substituents on the aromatic ring, where electron‐withdrawing substituents would stabilize dipoles with a partial negative charge predominantly in the benzylic position.…”