Facile, Novel Methodology for the Synthesis of Spiro[pyrrolidin-3,3′-oxindoles]: Catalyzed Ring Expansion Reactions of Cyclopropanes by Aldimines

• Published in: Angewandte Chemie (International ed.) Vol. 38; no. 21; pp. 3186 - 3189
• Main Authors: Alper, Phil B., Meyers, Christiane, Lerchner, Andreas, Siegel, Dionicio R., Carreira, Erick M.
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY-VCH Verlag GmbH 02.11.1999; WILEY‐VCH Verlag GmbH; Wiley
• Subjects: Alkaloids; Catalysts; Chemistry; Chemistry, Multidisciplinary; Cyclopropanes; Iodides; Lewis acid; Magnesium; Methodology; Nucleophilic additions; Organic compounds; Physical Sciences; Ring expansions; Science & Technology; Spiro compounds; Synthesis; ORGANIC-SYNTHESIS; ASYMMETRIC-SYNTHESIS; STEREOCONTROLLED TOTAL SYNTHESIS; ring expansions; alkaloids; cyclopropanes; nucleophilic additions; spiro compounds; DERIVATIVES; (+/-)-GELSEMINE; EFFICIENT

The role of the bifunctional catalyst is decisive: The magnesium ion as Lewis acid and its nucleophilic iodide counterion contribute in synergy to the successful ring expansion of the cyclopropane 1 by aldimine 2 [Eq. (1)]. This reaction offers a novel route to spiro[pyrrolidin‐3,3′‐oxindoles] 3....