title: Intramolecular Redox-Mannich Reactions: Facile Access to the Tetrahydroprotoberberine Core.
abstract: Cyclic amines such as pyrrolidine undergo redox-annulations with 2-formylaryl malonates. Concurrent oxidative amine α-CH bond functionalization and reductive N-alkylation render this transformation redox-neutral. This redox-Mannich process provides regioisomers of classic Reinhoudt reaction products as an entry to the tetrahydroprotoberberine core, enabling the synthesis of (±)-thalictricavine and its epimer. An unusually mild amine-promoted dealkoxycarbonylation was discovered in the course of these studies.
authors.affiliation: Department of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey, Piscataway, NJ 08854 (USA) http://seidel-group.com.
authors.forename: Longle
authors.initials: L
authors.lastname: Ma
authors.affiliation: Department of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey, Piscataway, NJ 08854 (USA) http://seidel-group.com. seidel@rutchem.rutgers.edu.
authors.forename: Daniel
authors.initials: D
authors.lastname: Seidel
mesh_terms: D000588:Amines / Q000737:chemistry*; D001600:Berberine Alkaloids / Q000138:chemical synthesis* / Q000737:chemistry; D002384:Catalysis; D003500:Cyclization; D015394:Molecular Structure; D010084:Oxidation-Reduction; D011759:Pyrrolidines / Q000737:chemistry*
chemical_list: D000588:Amines; D001600:Berberine Alkaloids; D011759:Pyrrolidines; C014845:berbine; C032519:pyrrolidine
keywords: CH functionalization; azomethine ylides; heterocycles; redox chemistry; synthetic methods