Radical-Induced Cascade Annulation/Hydrocarbonylation for Construction of 2-Aryl-4H-chromen-4-ones

Abstract

A robust metal- and solvent-free cascade radical-induced C-N cleavage/intramolecular 6-endo-dig annulation/hydrocarbonylation for the synthesis of the valuable 2-aryl-4H-chromen-4-ones is described. This practical synthesis strategy utilizes propargylamines and air as the oxygen source and green carbonylation reagent, in which propargylamines are activated by the inexpensive and available dimethyl 2,2′-azobis(2-methylpropionate) (AIBME) and (PhSe)2 as the radical initiators. This simple and green protocol features wide substrate adaptability, good functional group tolerance, and amenability to scaling up and derivatizations.

Synthesis of Flavones through NaI‐Mediated Electrochemical Cyclization of Chalcones

“…The authors have cited additional references within the Supporting Information. [75][76][77][78][79][80][81][82][83][84][85][86]…”

Substituent-Controllable Cascade Regioselective Annulation of β-Enaminones with N-Sulfonyl Triazoles for Modular Access to Imidazoles and Pyrroles

“…In addition to common reactivities such as cyclopropanation [23,24], X-H insertion [25][26][27][28], and ylide formation [29][30][31], α-imino rhodium carbenes can also serve as [1C]-or aza-[3C]-synthons in stepwise cycloadditions, leading to the formation of various N-heterocycles [32][33][34][35]. As a major part of our research efforts in developing new methodologies for the construction of heterocycles [36][37][38][39], we herein describe an efficient strategy for the regioselective synthesis of trisubstituted imidazoles and pyrroles. This strategy involves the cascade N-H insertion to α-imino rhodium carbene, followed by…”