title: Alkynyl Acylammoniums as Electrophilic 3C Synthons in a Formal [3 + 3] Annulation: Access to Functionalized 4H-Pyran-4-ones.
abstract: Alkynyl acylammoniums generated in situ from alkynyl acids are first used as electrophilic 3C synthons in a formal [3 + 3] annulation with 1,3-dicarbonyl compounds for regioselective synthesis of functionalized 4H-pyran-4-ones via a 4-(dimethylamino)pyridine/Lewis acid dual-activation strategy. This protocol paves the way for further investigation of alkynyl acylammoniums as 3C synthons for construction of diverse heterocyclic skeletons.
authors.affiliation: State Key Laboratory of Natural Medicines, Department of Organic Chemistry, China Pharmaceutical University , Nanjing 210009, P. R. China.
authors.forename: Shuding
authors.initials: S
authors.lastname: Dong
authors.affiliation: State Key Laboratory of Natural Medicines, Department of Organic Chemistry, China Pharmaceutical University , Nanjing 210009, P. R. China.
authors.forename: Chao
authors.initials: C
authors.lastname: Fang
authors.affiliation: State Key Laboratory of Natural Medicines, Department of Organic Chemistry, China Pharmaceutical University , Nanjing 210009, P. R. China.
authors.forename: Weifang
authors.initials: W
authors.lastname: Tang
authors.affiliation: State Key Laboratory of Natural Medicines, Department of Organic Chemistry, China Pharmaceutical University , Nanjing 210009, P. R. China.
authors.forename: Tao
authors.initials: T
authors.lastname: Lu
authors.affiliation: State Key Laboratory of Natural Medicines, Department of Organic Chemistry, China Pharmaceutical University , Nanjing 210009, P. R. China.
authors.forename: Ding
authors.initials: D
authors.lastname: Du