title: Pd-catalyzed cascade reactions between o-iodo-N-alkenylanilines and tosylhydrazones: novel approaches to the synthesis of polysubstituted indoles and 1,4-dihydroquinolines.
abstract: Two different Pd-catalyzed cascade reactions between o-iodo-N-alkenylanilines and tosylhydrazones are described. The outcome of the cascade processes is determined by the substitution on the N-alkenyl fragment. The reactions with N-tosyl-N-ethylene-o-iodoanilines lead to indoles through a sequence that involves the sequential migratory insertions of a carbene ligand and a C-C double bond, featuring a 5-exo-trig cyclization. The reactions with N-alkyl-N-alkenyl-o-iodoanilines provide 1,4-dihydroquinolines through a cascade reaction that includes a formal 6-endo-trig cyclization. In both cases the benzofused heterocycles are built through the formation of two C-C bonds on the hydrazonic carbon atom.
authors.affiliation: Departamento de Química Orgánica e Inorgánica and Instituto Universitario de Química Organometálica "Enrique Moles", Universidad de Oviedo, c/ Julián Clavería 8, Oviedo, 33006, Spain. acvg@uniovi.es.
authors.forename: Miguel
authors.initials: M
authors.lastname: Paraja
authors.forename: Carlos
authors.initials: C
authors.lastname: Valdés
mesh_terms: D000814:Aniline Compounds / Q000737:chemistry*; D002384:Catalysis; D006835:Hydrazones / Q000737:chemistry*; D007211:Indoles / Q000138:chemical synthesis* / Q000737:chemistry; D015394:Molecular Structure; D010165:Palladium / Q000737:chemistry*; D011804:Quinolines / Q000138:chemical synthesis* / Q000737:chemistry
chemical_list: C544515:1,4-dihydroquinoline; D000814:Aniline Compounds; D006835:Hydrazones; D007211:Indoles; D011804:Quinolines; D010165:Palladium