Study On The Synthesis Of Ynones Derivatives By Oxidation Of Propargyl Alcohol With Weak Oxidant

Ynones and its derivatives,as an important organic structural unit,widely exist in various natural products and drug molecules.These compounds have special pharmacological and optical activities,and have important application value in biology,medicine,luminescent materials and other fields.Because of its special structure of alkyne bond and car bonyl bifunctional group,ynones are used as substrates with high reaction activity,which can be Michael added with various nucleophiles to form other molecules with complex structure.Therefore,acetylacetone has been considered as the key intermediate in the synthesis of natural products and complex compounds.In recent years,many synthetic methods of ynones have been reported,but these methods still have some shortcomings,such as: harsh reaction conditions,more by-products,poor selectivity,expensive catalysts or oxidants,environmental pollution,etc.Therefore,it is very valuable to develop an efficient,clean and mild oxidation method.In this paper,N-iodobutyrylimide was used to oxidize propargyl alcohol to propargyl acetone.First of all,we optimized the reaction conditions,and determined the optimized reaction condition as follows: 1,3-diphenylpropyl-2-alkyne-1-ol(1equiv),oxidant N-iodobutyrylimide(1.2equiv),acetonitrile(2mL)as solvent,reaction for 5h,reaction at room temperature.Then,we studied the application range of the reaction substrate under the optimal reaction conditions.The experimental results show that almost all the substrates with different substituents can produce ynones in a good yield.Finally,we proposed the possible mechanism of the reaction,and further studied the derivatization of ynones,and finally synthesized pyrazoles.This reaction not only has the characteristics of mild reaction conditions and good atom economy,but also provides a clean,mild and potential application method for the synthesis of alkyne acetone and its derivatives.