Stereoselective quaternization of alpha-amino phenylacetonitriles mediated by a remote sulfinyl group.
Enantiomerically pure alpha-substituted alpha-amino phenylacetonitriles have been readily prepared from 2-p-tolylsulfinylbenzaldimines following a two-step sequence: a moderately stereoselective hydrocyanation of the imines and a completely stereoselective quaternization of the resulting diastereoisomeric mixture of alpha-amino phenylacetonitriles with different alkylating or acylating reagents in the presence of KHMDS. Theoretical calculations support a stereoselectivity control exerted by the remote sulfinyl group, as long as it is responsible for the conformational preferences of the benzyllithium intermediates, which suffer the attack of the electrophiles to the less hindered diastereotopic face.
Ruano
José Luis García
JL
Departamento de Química Orgánica, Universidad Autónoma de Madrid, Cantoblanco, 28049 Madrid, Spain. joseluis.garcia.ruano@uam.es
Martín-Castro
Ana M
AM
Tato
Francisco
F
Alonso
Inés
I
D000097:Acetonitriles / Q000737:chemistry*; D000477:Alkylating Agents / Q000737:chemistry; D000838:Anions / Q000737:chemistry; D001554:Benzene / Q000737:chemistry; D002244:Carbon / Q000737:chemistry; D002625:Chemistry, Organic / Q000379:methods*; D008094:Lithium / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D008956:Models, Chemical; D008958:Models, Molecular; D008968:Molecular Conformation; D010100:Oxygen / Q000737:chemistry; D011522:Protons; D013237:Stereoisomerism; D013455:Sulfur / Q000737:chemistry
D000097:Acetonitriles; D000477:Alkylating Agents; D000838:Anions; D011522:Protons; C006725:benzyl cyanide; D013455:Sulfur; D002244:Carbon; D008094:Lithium; D001554:Benzene; D010100:Oxygen