Addition of Grignardreagents 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 arylGrignardreagents. In one case, the absolute configuration at C3 was determined and the selective N-deprotection was described, enabling
An unprecedented chiral spiropiperidine oxindole system quaternary 3-aminooxindole and relying on a ring closing acts as an highly constrained Freidinger gamma-lactam, adopting assessed by modelling and spectroscopical studies. was synthesized starting from enantiopure metathesis as the key step. This compound a type II beta-turn conformation in solution, as (C) 2010 Elsevier Ltd. All rights reserved.