title: Titanium-catalyzed stereoselective synthesis of spirooxindole oxazolines.
abstract: A regio- and stereoselective cyclization between isatins and 5-methoxyoxazoles has been developed using catalytic titanium(IV) chloride (10 or 20 mol %) to afford spiro[3,3'-oxindoleoxazolines] in excellent yield (up to 99%) and diastereoselectivity (dr >99:1). Substitution at the 4-position of the oxazole controls nucleophilic attack to provide either the 2-oxazoline or 3-oxazoline spirocycle with excellent (>99:1) regiocontrol.
authors.affiliation: Department of Chemistry, University of California, One Shields Avenue, Davis, California 95616, USA.
authors.forename: Joseph J
authors.initials: JJ
authors.lastname: Badillo
authors.forename: Gary E
authors.initials: GE
authors.lastname: Arevalo
authors.forename: James C
authors.initials: JC
authors.lastname: Fettinger
authors.forename: Annaliese K
authors.initials: AK
authors.lastname: Franz
mesh_terms: D002384:Catalysis; D020650:Combinatorial Chemistry Techniques; D003500:Cyclization; D007211:Indoles / Q000138:chemical synthesis* / Q000737:chemistry*; D007510:Isatin / Q000737:chemistry*; D015394:Molecular Structure; D010080:Oxazoles / Q000138:chemical synthesis* / Q000737:chemistry*; D013141:Spiro Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D013237:Stereoisomerism; D014025:Titanium / Q000737:chemistry*
chemical_list: D007211:Indoles; D010080:Oxazoles; D013141:Spiro Compounds; D007510:Isatin; D014025:Titanium