Preparations of Secondary Amines and β-Amino Esters via Additions of Grignard and Reformatsky Reagents to Imines and by One-Pot Reactions of Primary Amines, Aldehydes, and Grignards

摘要

Additions of Grignard and Reformatsky reagents to imines in the presence of 1-(trimethylsilyl)-benzotriazole afforded in good yields the corresponding secondary amines and β-amino esters. The procedure is general as imines containing hydrogens α to both carbon and nitrogen can be employed. Extensions of this method to include imines containing other Lewis basic centers, e.g., those derived from furan-, thiophene-, indole-, and p-methoxybenzenecarboxaldehyde, have been successful in avoiding the potential complications which could result from the use of a Lewis acid as the activating species. The imines need not be isolated, and a one-pot method for the synthesis of secondary amines from aldehydes, primary amines, and Grignard reagents is described.