title: Intramolecular [3 + 2]-cycloadditions of azomethine ylides derived from secondary amines via redox-neutral C-H functionalization.
abstract: Azomethine ylides are accessed under mild conditions via benzoic acid catalyzed condensations of 1,2,3,4-tetrahydroisoquinolines or tryptolines with aldehydes bearing a pendent dipolarophile. These intermediates undergo intramolecular [3 + 2]-cycloadditions in a highly diastereoselective fashion to form polycyclic amines with four new stereogenic centers. Challenging substrates such as piperidine, morpholine, and thiomorpholine undergo the corresponding reactions at elevated temperatures.
authors.affiliation: Department of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey , Piscataway, New Jersey 08854, United States.
authors.forename: Kempegowda
authors.initials: K
authors.lastname: Mantelingu
authors.forename: Yingfu
authors.initials: Y
authors.lastname: Lin
authors.forename: Daniel
authors.initials: D
authors.lastname: Seidel
mesh_terms: D000447:Aldehydes / Q000737:chemistry; D000588:Amines / Q000138:chemical synthesis / Q000737:chemistry*; D001391:Azo Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D019817:Benzoic Acid / Q000737:chemistry*; D002384:Catalysis; D003500:Cyclization; D061565:Cycloaddition Reaction; D006576:Heterocyclic Compounds, 4 or More Rings / Q000138:chemical synthesis* / Q000737:chemistry; D015394:Molecular Structure; D010084:Oxidation-Reduction; D013237:Stereoisomerism; D044005:Tetrahydroisoquinolines / Q000737:chemistry*; D013882:Thiosemicarbazones / Q000138:chemical synthesis* / Q000737:chemistry
chemical_list: D000447:Aldehydes; D000588:Amines; D001391:Azo Compounds; D006576:Heterocyclic Compounds, 4 or More Rings; D044005:Tetrahydroisoquinolines; D013882:Thiosemicarbazones; C512188:azomethine; D019817:Benzoic Acid