title: [3+2] coupling of quinone monoacetals by combined acid-hydrogen bond donor.
abstract: The expeditious and efficient [3+2] coupling approach of quinone monoacetals 1 with alkene nucleophiles 2 by the action of an activated Brønsted acid in the presence of a hydrogen bond donor perfluorinated alcohol has been achieved. With the optimized combined acid, the reaction could proceed under mild conditions by only mixing the two reactants to afford the cycloadducts 3 in a short time (within 10 min) with good to quantitative yields.
authors.affiliation: College of Pharmaceutical Sciences, Ritsumeikan University, 1-1-1 Nojihigashi, Kusatsu, Shiga, 525-8577, Japan.
authors.forename: Toshifumi
authors.initials: T
authors.lastname: Dohi
authors.forename: Yinjun
authors.initials: Y
authors.lastname: Hu
authors.forename: Tohru
authors.initials: T
authors.lastname: Kamitanaka
authors.forename: Naohiko
authors.initials: N
authors.lastname: Washimi
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Kita
mesh_terms: D000080:Acetals / Q000737:chemistry*; D000143:Acids / Q000737:chemistry*; D000475:Alkenes / Q000737:chemistry; D016227:Benzoquinones / Q000737:chemistry*; D003500:Cyclization; D004987:Ethers / Q000138:chemical synthesis* / Q000737:chemistry; D006860:Hydrogen Bonding; D015394:Molecular Structure; D013237:Stereoisomerism
chemical_list: D000080:Acetals; D000143:Acids; D000475:Alkenes; D016227:Benzoquinones; D004987:Ethers; C004532:quinone