title: Enantioselective synthesis of 1,2-dihydronaphthalene-1-carbaldehydes by addition of boronates to isochromene acetals catalyzed by tartaric acid.
abstract: Tartaric acid is an ideal asymmetric catalyst as it is abundant, cheap, and environmentally friendly. (+)-Tartaric acid was found to catalyze a novel enantioselective [4 + 2] cycloaddition of isochromene acetals and vinylboronates. A variety of substituted isochromene acetals were tolerated, furnishing the desired dihydronaphthalenes and dihydrobenzofluorene products in good yields. High enantiomeric ratios (up to 98.5:1.5) and excellent diastereoselectivities (all >99:1) were observed employing 10 mol % of (+)-tartaric acid as the catalyst, in combination with 5 mol % of Ho(OTf)3.
authors.affiliation: Department of Chemistry, Boston University , 24 Cummington Street, Boston, Massachusetts 02215, United States.
authors.forename: Yi
authors.initials: Y
authors.lastname: Luan
authors.forename: Keith S
authors.initials: KS
authors.lastname: Barbato
authors.forename: Philip N
authors.initials: PN
authors.lastname: Moquist
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Kodama
authors.forename: Scott E
authors.initials: SE
authors.lastname: Schaus
mesh_terms: D000080:Acetals / Q000737:chemistry*; D000447:Aldehydes / Q000138:chemical synthesis / Q000737:chemistry*; D001896:Boron Compounds / Q000737:chemistry*; D060326:Chemistry Techniques, Synthetic; D009281:Naphthalenes / Q000737:chemistry*; D013237:Stereoisomerism; D013644:Tartrates / Q000737:chemistry*
chemical_list: D000080:Acetals; D000447:Aldehydes; D001896:Boron Compounds; D009281:Naphthalenes; D013644:Tartrates; C086079:1,2-dihydronaphthalene; C029768:tartaric acid