title: An enantioselective approach toward 3,4-dihydroisocoumarin through the bromocyclization of styrene-type carboxylic acids.
abstract: A facile and enantioselective approach toward 3,4-dihydroisocoumarin was developed. The method involved an amino-thiocarbamate catalyzed enantioselective bromocyclization of styrene-type carboxylic acids, yielding 3-bromo-3,4-dihydroisocoumarins with good yields and ee's. 3-Bromo-3,4-dihydroisocoumarins are versatile building blocks for various dihydroisocoumarin derivatives in which the Br group can readily be modified to achieve biologically important 4-O-type and 4-N-type 3,4-dihydroisocoumarin systems. In addition, studies indicated that, by refining some parameters, the synthetically useful 5-exo phthalide products could be achieved with good yields and ee's.
authors.affiliation: Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543.
authors.forename: Jie
authors.initials: J
authors.lastname: Chen
authors.forename: Ling
authors.initials: L
authors.lastname: Zhou
authors.forename: Chong Kiat
authors.initials: CK
authors.lastname: Tan
authors.forename: Ying-Yeung
authors.initials: YY
authors.lastname: Yeung
mesh_terms: D002264:Carboxylic Acids / Q000138:chemical synthesis / Q000737:chemistry*; D060326:Chemistry Techniques, Synthetic; D003374:Coumarins / Q000737:chemistry*; D003500:Cyclization; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D013237:Stereoisomerism; D020058:Styrene / Q000737:chemistry*
chemical_list: D002264:Carboxylic Acids; D003374:Coumarins; D020058:Styrene; C026308:3,4-dihydrocoumarin