Study On The Preparation Of Dienamide Compounds Via One Pot Tandem Reaction

Compounds containing dienamide structures are prevalent among biologically active molecules,which is a kind of very promising drug substance.In recent years,the organic chemical reactions catalyzed by small molecule N or P-containing catalyst have developed into a methodological system for the preparation of various functionalized unsaturated carbocyclic and heterocy clic compounds.Based on the work of tandem cyclization of formaldehyde-derived allyl carbonate catalyzed by tertiary phosphine,we studi ed the synthesis of the dienamide compounds containing trifluoromethyl tertiary alcohol structure by one-pot synthesis of tandem amidation reaction,and tried a method of preparing bicyclic lactone in a one pot process with electron-deficient allenoate through ring addition reaction.(1)Nucleophilic phosphine promotes the tandem reaction between allyl carbonate and two molecules of trifluoromethyl ketone to obtain the vinyl lactone intermediate,which can react with morphine in situ in the presence of DBU(1,8-Diazabicyclo[5.4.0]undec-7-ene).The whole reaction follows a sequence of addition / lactonization / Wittig / Amminolysis in one pot,and produces a series of dienamide compounds with trifluoromethyl tertiary alcohol structure.(2)Changing the reaction conditions,the lactone intermediate obtained by the phosphine-promoted tandem reaction was allowed to undergo the conventional P-catalyzed [3 + 2] cycloaddition reaction in situ with allenoate.This sequential transformation enabled a cost-effective and step-economical approach to access trifluoromethylated bicyclic lactone compounds with structural complexity from readily accessible reagent and starting materials.