title: Catalytic enantioselective formal hetero-Diels-Alder reactions of enones with isatins to give spirooxindole tetrahydropyranones.
abstract: Organocatalytic formal hetero-Diels-Alder reactions of enones with isatins, which gave highly enantiomerically enriched functionalized spirooxindole tetrahydropyranones via an enamine-based mechanism, were developed. The catalyst systems were identified by a screen of combinations of amines, acids, and additives. With the identified catalyst systems, various spirooxindole tetrahydropyranones were synthesized in high yields with high diastereo- and enantioselectivities (see scheme).
authors.affiliation: Chemistry and Chemical Bioengineering Unit (Kyoto Lab), Okinawa Institute of Science and Technology Graduate University, Mikuruma, 448-5 Kajii, Kamigyo, Kyoto 602-0841, Japan.
authors.forename: Hai-Lei
authors.initials: HL
authors.lastname: Cui
authors.forename: Fujie
authors.initials: F
authors.lastname: Tanaka
mesh_terms: D000588:Amines / Q000737:chemistry; D002384:Catalysis; D061565:Cycloaddition Reaction; D007211:Indoles / Q000138:chemical synthesis* / Q000737:chemistry; D007510:Isatin / Q000737:chemistry*; D007659:Ketones / Q000737:chemistry*; D015394:Molecular Structure; D000078183:Oxindoles; D011753:Pyrones / Q000138:chemical synthesis* / Q000737:chemistry; D013141:Spiro Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D013237:Stereoisomerism
chemical_list: D000588:Amines; D007211:Indoles; D007659:Ketones; D000078183:Oxindoles; D011753:Pyrones; D013141:Spiro Compounds; C022960:2-oxindole; D007510:Isatin