title: Cu-catalyzed aerobic oxidative cyclizations of 3-N-hydroxyamino-1,2-propadienes with alcohols, thiols, and amines to form α-O-, S-, and N-substituted 4-methylquinoline derivatives.
abstract: A one-pot, two-step synthesis of α-O-, S-, and N-substituted 4-methylquinoline derivatives through Cu-catalyzed aerobic oxidations of N-hydroxyaminoallenes with alcohols, thiols, and amines is described. This reaction sequence involves an initial oxidation of N-hydroxyaminoallenes with NuH (Nu = OH, OR, NHR, and SR) to form 3-substituted 2-en-1-ones, followed by Brønsted acid catalyzed intramolecular cyclizations of the resulting products. Our mechanistic analysis suggests that the reactions proceed through a radical-type mechanism rather than a typical nitrone-intermediate route. The utility of this new Cu-catalyzed reaction is shown by its applicability to the synthesis of several 2-amino-4-methylquinoline derivatives, which are known to be key precursors to several bioactive molecules.
authors: Department of Chemistry, National Tsing-Hua University, Hsinchu (30013) (Taiwan).
authors: Pankaj
authors: P
authors: Sharma
authors: Rai-Shung
authors: RS
authors: Liu
mesh_terms: D000438:Alcohols / Q000737:chemistry*; D000466:Alkadienes / Q000737:chemistry*; D000588:Amines / Q000737:chemistry*; D002384:Catalysis; D003300:Copper / Q000737:chemistry*; D003500:Cyclization; D005609:Free Radicals / Q000737:chemistry; D009584:Nitrogen / Q000737:chemistry; D009589:Nitrogen Oxides / Q000737:chemistry; D010084:Oxidation-Reduction; D010100:Oxygen / Q000737:chemistry; D011804:Quinolines / Q000737:chemistry*; D013438:Sulfhydryl Compounds / Q000737:chemistry*; D013455:Sulfur / Q000737:chemistry
chemical_list: D000438:Alcohols; D000466:Alkadienes; D000588:Amines; D005609:Free Radicals; D009589:Nitrogen Oxides; D011804:Quinolines; D013438:Sulfhydryl Compounds; C015388:nitrones; C057608:4-methylquinoline; C025947:propadiene; D013455:Sulfur; D003300:Copper; D009584:Nitrogen; D010100:Oxygen
keywords: 4-methylquinolines; aerobic oxidation; copper; hydroxyaminoallenes; radical reactions