Mechanistic aspects of the Strecker aminonitrile synthesis

Abstract

Asymmetric a-aminonitriles could not be prepared by the Strecker procedure catalysed by optically active acids or bases. Benzylideneaniline reacted readily and quantitatively with hydrogen cyanide to give a-cyanobenzylaniline, while mandelonitrile reacted very slowly with aniline, indicating that benzylideneaniline or a Schiff base may be an intermediate for the Strecker synthesis. The addition of hydrogen cyanide to benzylideneaniline in acetonitrilemethanol at 25 "C follows a third-order rate equation :The rate is higher in protic dipolar solvents than in aprotic non-polar solvents. An electron-releasing group on either of the rings increases the rate with Hammett p values of -1.1 1 in the benzylidene and -1.39 in the aniline ring. A mechanism involving methanol-catalysed addition of hydrogen cyanide to benzylideneaniline is postulated and discussed.Chikusa-ku, Nagoya, Japan

A theoretical study of imine hydrocyanation catalyzed by halogen‐bonding

“…In Figures , the relative energy profiles of the reaction pathways according to Figures and in the gas phase and in toluene are displayed. In general, an imine hydrocyanation reaction benefits from polar and protic solvents such as methanol and is decelerated in nonpolar aprotic solvents such as toluene . In this case, however, toluene is chosen as a solvent in view of an application of this system in asymmetric catalysis, as the catalysis of imine hydrocyanation by chiral Lewis or Brønsted acids is considered to be most effective in this environment …”

“…In general, an imine hydrocyanation reaction benefits from polar and protic solvents such as methanol and is decelerated in nonpolar aprotic solvents such as toluene. [36] In this case, however, toluene is chosen as a solvent in view of an application of this system in asymmetric catalysis, [37,38] as the catalysis of imine hydrocyanation by chiral Lewis or Brønsted acids is considered to be most effective in this environment. [39][40][41] For all considered reactions, the activation energy barriers are lowered in the case of the reaction in toluene in comparison to the gas phase.…”

Stereoselective Synthesis of α-Arylalkylamines by Glycosylation-induced Asymmetric Addition of Organometallic Compounds to Imines

“…To overcome this disadvantage, the structure of the model imine was modified, and N-benzylidene-pmethoxy-aniline [19] (8) was investigated as the substrate (Scheme 5).…”

“…In this case, 0.16 g (0.75 mmole) N-benzylidene-(4-methoxyphenyl)amine [19] (8) N-(4-methoxy-phenyl)-(1-phenyl)-propylamine (11) was neutralized with 1N NaOH. To the neutral solution 0.825 g (1.5 mmol) of ceric ammonium nitrate was added.…”

Synthesis and Characterization of New Metal Complexes of α-Aminonitriles Derived from P- Toluidine and Aromatic Aldehydes

“…Furthure more aminonitrile is potentially a chelating ligand [9,10]. These amino nitriles were synthesized by a modified Strecker's procedure [11,12], all above gave us the motives to synthesis and characterization of a new series of transition metal ions Co(II), Cu(II), Cd(II) and Zn(II) complexes by their reaction with two -aminonitriles HL I and HL II which were previously prepared [13].…”