Enantioselective synthesis of functionalized 1,4-dihydropyrazolo-[4′,3′:5,6]pyrano[2,3-<i>b</i>]quinolines through ferrocenyl-phosphine-catalyzed annulation of modified MBH carbonates and pyrazolones
Xiao Xiao, Bingxuan Shao, Jingyi Li, Zehui Yang, Yin‐Jie Lu, Fei Ling, Weihui Zhong
Abstract
An enantioselective synthesis of highly functionalized 1,4-dihydropyrazolo[4',3':5,6]pyrano[2,3-b]quinolines from modified MBH carbonates and pyrazolones via a chiral phosphine-mediated alkylation/annulation sequence has been realized. The chiral dihydropyrano[2,3-c]pyrazoles bearing bio-active condensed heterocycles were facilely formed in good chemical yields and with high to excellent enantioselectivity by utilizing low catalyst loading.
Topics & Concepts
PyrazolonesAnnulationEnantioselective synthesisPhosphineChemistryAlkylationCatalysisCombinatorial chemistryStereochemistryMedicinal chemistryOrganic chemistryAsymmetric Synthesis and CatalysisSulfur-Based Synthesis TechniquesCatalytic C–H Functionalization Methods