Oxidative Cyclization of Aryl Ynones with NaNO<sub>2</sub> for the Divergent Synthesis of NO<sub>2</sub>‐Containing Spiro[5.5]trienones, Indenones and Thioflavones
Wenchao Yang, Liu‐Yu Shen, Junnan Li, Jianguo Feng, Pinhua Li
Abstract
Abstract A K 2 S 2 O 8 ‐promoted nitration/spirocyclization of biaryl ynones using inexpensive NaNO 2 as nitro source has been described. This cascade reaction is triggered by nitration of alkyne and followed by 6‐exo‐trig spirocyclization, dearomatization, forming the NO 2 ‐containing spiro[5.5]trienones in 63–85% yields. The present reaction also provides a practical method for the synthesis of nitrated indenones and thioflavones with 58–85% yields. magnified image
Topics & Concepts
NitrationChemistryAlkyneArylOxidative phosphorylationCombinatorial chemistryNitroCascadeOrganic chemistryCatalysisBiochemistryChromatographyAlkylOxidative Organic Chemistry ReactionsCatalytic C–H Functionalization MethodsSynthesis of Organic Compounds