Diastereoselective Generation of C<sub>2</sub>-Azlactonized 2<i>H</i>-Chromenes via Brønsted Acid-Catalyzed Oxo-Cyclization of Propargyl Alcohols
Meng-Ying Hao, Minhua Huang, Xinyu Gu, Tian-Shu Zhang, Xiaotong Zhu, Wen‐Juan Hao, Bo Jiang
Abstract
A new Brønsted acid-catalyzed oxo-cyclization of propargyl alcohols with azlactones to synthesize C2-azlactonized 2H-chromenes has been established that uses 1,1′-binaphthyl-2,2′-diyl hydrogen phosphate (BiNPO4H) as the catalyst and gives excellent diastereoselectivities (≥19:1 dr) in most cases. This protocol has a high compatibility with various substituents of substrates, offering a catalytic and useful entry to the fabrication of the synthetically important C2-functionalized 2H-chromene scaffold.
Topics & Concepts
PropargylCatalysisChemistryBrønsted–Lowry acid–base theoryCompatibility (geochemistry)Combinatorial chemistryOrganic chemistryPhosphateMaterials scienceComposite materialCatalytic C–H Functionalization MethodsOxidative Organic Chemistry ReactionsCatalytic Alkyne Reactions