Grignard addition to imines derived from isatine: a method for the asymmetric synthesis of quaternary 3-aminooxindoles.
Addition of Grignard reagents to chiral imines derived from isatine afforded chiral, optically enriched 3-substituted 3-aminooxindoles in satisfactory yields and diastereoisomeric ratios. A general protocol is described for the addition of alkyl, alkenyl, and aryl Grignard reagents. In one case, the absolute configuration at C3 was determined and the selective N-deprotection was described, enabling further synthetic transformations of the reaction product.
Dipartimento di Chimica Organica e Industriale, Università degli Studi di Milano, via G. Venezian 21, 20133 Milano, Italy.
Giordano
G
Lesma
Nicola
N
Landoni
Tullio
T
Pilati
Alessandro
A
Sacchetti
Alessandra
A
Silvani
D007097:Imines / Q000737:chemistry*; D007211:Indoles / Q000138:chemical synthesis*; D000644:Quaternary Ammonium Compounds / Q000138:chemical synthesis*; D013237:Stereoisomerism
D007097:Imines; D007211:Indoles; D000644:Quaternary Ammonium Compounds