Substrate-Controlled Product Divergence: Silver-Catalyzed Reaction of Trifluoromethyl Ketones with Terminal Alkynes

Abstract

A distinct dichotomy in product distribution was initially observed in the silver-catalyzed reaction of trifluoromethyl (CF 3 ) ketones with terminal alkynes having two different types of electronic natures. The domino reaction smoothly proceeded almost exclusively with high stereoselectivity with terminal alkynes containing ester groups, whereas alkynylation occurred in good yield when terminal alkynes containing aryl or alkyl groups were present. The results indicated that the electronic nature of terminal alkynes can act as a switch that enables either the domino reaction or alkynylation between terminal alkynes and CF 3 ketones.

Application of Silver Compounds in Fluoroorganic Synthesis: A Minireview

“…Mechanism of silver-catalyzed reaction of trifluoromethyl ketones with terminal alkynes depending on functional group near triple bond: (a) propargylate esters; (b) terminal alkynes, R 2 = alkyl or aryl. [132] Scheme 3. Synthesis of β-fluoroenones from acetylenic ketones using AgF.…”

“…The alkylation or domino reaction between aryl trifluoromethyl ketones and terminal alkynes using silver(I) as the catalyst (with AgCl as initiator, which is partly solubilized using potassium salts) has been reported by Dai group in 2017 [132] . In this method, the reaction path is determined by the electronic substituents of the terminal alkynes.…”

“… Silver‐catalyzed reaction of trifluoromethyl ketones with terminal alkynes [132] with scope of tested substrates.…”

“…The alkylation or domino reaction between aryl trifluoromethyl ketones and terminal alkynes using silver(I) as the catalyst (with AgCl as initiator, which is partly solubilized using potassium salts) has been reported by Dai group in 2017. [132] In this method, the reaction path is determined by the electronic substituents of the terminal alkynes. Alkynylation ensued with exceptionally high yields when aryl or alkyl substituents are present in the terminal alkynes (Scheme 1), whereas the domino reaction progressed exclusively with excellent stereoselectivity when propargylate esters were utilized.…”

Solvent-Controlled Switchable Domino Reactions of MBH Carbonate: Synthesis of Benzothiophene Fused α-Pyran, 2,3-Dihydrooxepine, and Oxatricyclodecene Derivatives

“…The development of switchable intermolecular domino reactions from identical substrates in different regioselective methods is very challenging yet highly desirable in modern organic chemistry, especially organocatalytic switchable intermolecular domino reactions. Such reactions have many advantages: they are atom-economical, have fewer synthetic steps, and minimize the amount of purification required . Thus, considerable effort has gone into developing efficient domino reactions.…”