Synthesis Of α-oxygenated Ketones From Alkynes By Using Iodobenzene Dicarboxylate As Transferrable Oxygen Sources

Theα-Oxygenated ketones are common structural motifs in a variety of naturalproducts and represent one class of important intermediates in the synthesis ofbiologically active compounds and pharmaceuticals. In view of the importance of theα-Oxygenated ketones,many organic chemists and medicinal chemists have beendeveloped to prepareα-Oxygenated ketones.This paper developed a simple and efficient, the environmental pollution-freeand practical new method for the synthesis ofα-Oxygenated ketones. Under thecondition of room temperature,we set off from the alkyne, hypervalent iodine(III)reagents as oxidant, hypervalent iodine(III) reagents itself as a source of oxygen at thesame time, the efficient synthesis of a series of aα-Oxygenated ketones products.Compared with the traditional synthesis method, not only to broaden the scope of thesubstrate, but also friendly to the environment, easy to operate, and could be reactedin gram scale. The optimal reaction conditions are as follows:1equivalents ofalkyne,1.2equivalents of iodobenzene dicarboxylates, dichloromethane as solvent, inthe closed system under room temperature. The experimental results show that whenthe alkynyl substituents are electron-withdrawing groups, the yields are lower, whenthe alkynyl substituents are electron-donating groups, the yields are lower. The scopeof hypervalent iodine(III) reagents was investigated, While iodobenzene ditriflateafforded-hydroxy ketones in high to excellent yields. The dual role of thehypervalent iodine(III) reagents as both an oxidant and transferrable O-nucleophile(s)were highlighted. The protocol represents a direct, atom-efficient and metal-freeconversion of alkynes intoα-Oxygenated ketones under mild conditions.