Radical selenylative cyclization of trifluoromethyl propargyl imines for the synthesis of trifluoromethyl- and seleno-azaspiro[4,5]-tetraenones and quinolines

Abstract

A radical selenylative cyclization of trifluoromethyl propargyl imines with diselenides for the regiodivergent construction of diversely functionalized azaspiro[4,5]-tetraenones and quinolines has been developed, which enable dual incorporation of CF3 and...

Recent advances in the synthesis of trifluoromethyl-containing heterocyclic compounds via trifluoromethyl building blocks

“…In 2023, Wu's group 92 introduced the oxone-promoted radical selenylative cyclization of trifluoromethyl propargyl imines and diselenides to selectively synthesize azaspiro [4,5]tetraenones and quinolines containing CF 3 and Se substitu- ents (Scheme 64). In addition, the reaction proceeds by oxidative dearomative ipso-annulation or intramolecular orthoannulation using oxone as a green oxidant, resulting in the formation of several heterocyclic products with excellent regio-selectivity.…”

Construction of trifluoromethyl-containing heterocycles from trifluoroacetimidoyl chlorides and derivatives

“…Wu, Chen and co-workers presented an Oxone-promoted radical selenylative cyclization of trifluoromethyl propargyl imines and diselenides for the assembly of trifluoromethyl and seleno-azaspiro[4,5]-tetraenones and quinolines (Scheme 25). 35 The trifluoromethyl propargyl imines could be easily prepared by palladium-catalyzed coupling of trifluoroacetimidoyl halides and terminal alkynes. When the R 2 group was methoxy group located at para -position of aryl ring, the oxidative dearomative ipso -annulation took place to give azaspiro[4,5]-tetraenone products by a sequential demethoxylation and a proton elimination process.…”

Recent Developments in the Synthesis of Organoselenium Compounds Based on the Reactions of Organic Diselenides with Acetylenes

“…Over the past few decades, this green oxidative reagent has become a powerful tool in organic synthesis [116]. Recently, potassium peroxymonosulfate was successfully used in a number of promising transformations with the formation of valuable organoselenium compounds including heterocyclic products [118][119][120][121][122][123][124][125][126][127][128].…”

“…Very interesting regiodivergent syntheses of diversely functionalized azaspiro [4,5]tetrae nones (26-92% yields, Scheme 38) and quinolines (38-99% yields, Scheme 39) via the radical cyclization reaction of trifluoromethyl propargyl imines with organic diselenides under the action of Oxone ® were recently developed [128]. In the case of the preparation of azaspiro [4,5]tetraenones, the starting substrates contained a strong electron-donating 4-methoxy substituent (Scheme 38).…”

“…The method provided the dual incorporation of both selenium and trifluoromethyl groups into heterocyclic molecules via a one-pot procedure. The synthetic utility of this method was shown by a scale-up reaction and the further modification of the obtained products [128].…”