Synthesis of spiropyrans <i>via</i> the Rh(<scp>iii</scp>)-catalyzed annulation of 3-aryl-2<i>H</i>-benzo[<i>b</i>][1,4]oxazines with diazo ketoesters
Jing Jing Zhang, Mengying Zhang, Mingxin Lu, Yuhao He, Li Song, Liangxin Fan, Xinle Zhang, Jiakai Wu, Xifa Yang
Abstract
twofold C-H activation followed by unusual [3+3] and [4+2] annulation with decent functional group tolerance. Moreover, a pyranoid-skeleton intermediate was isolated as a key intermediate as a result of monoalkylation and enol oxygen annulation, which offers direct mechanistic insight.
Topics & Concepts
AnnulationChemistryDiazoOxazinesEnolArylCatalysisMedicinal chemistryStereochemistryCombinatorial chemistryOrganic chemistryAlkylCatalytic C–H Functionalization MethodsCyclopropane Reaction MechanismsSynthesis and Catalytic Reactions