Synthesis Of ?'-aryloxide And ?'-arylamine-substituted ?,?-unsaturated Ketones Via Meyer-schuster Rearrangement

Including both carbonyl and alkenyl functional groups,the a,(3-unsaturated ketone has the chemical properties of ketone,olefin as well as conjugated diene.As an important intermediate,it acts as a good acceptor of Michael reaction or Diels-Alder reaction.It also has a wide application in medicine,pesticide,fine chemical and so on.For example,some ?,?-unsaturated ketones have the pharmacophore which can be used for the synthesis of anti-tumor inhibitors and some ?,?-unsaturated ketones have a natural fragrance which can be used for the synthesis of some fine chemicals.Aldol condensation is a classical method for the synthesis of ?,?-unsaturated ketones.However,its yield is often very low because the substrates can self-or crossed condensation reaction which result in the side reactions.So there is an important academic significance and application value to research a highly efficient method for the synthesis of ?,?-unsaturated ketones.Propargylic alcohols contain both terminal acetylenes and hydroxyl functional groups which can participate in several transformations.It's a very useful intermediate for the synthesis of natural medicine and drugs.The synthesis of ?,?-unsaturated ketones via Meyer-Schuster rearrangement is one of the important applications of propargylic alcohols.However,the Br(?)nsted acid often can't give the ideal yield.Furthermore,the metal complexes which are researched recently are expensive when they are used for this reaction.In this paper,we firstly synthesize the phenol-and amine-substituted propargylic alcohols.Then,?'-arlyoxide-and ?'-arylamine substituted a,p-unsaturated ketones were synthesized by the Meyer-Schuster rearrangement when the propargylic alcohols were catalyzed by FeCl3·6H2O.Part 1:Using the variety of substituted phenol and N-tosyl amine as the raw material which react with propargyl bromide,we synthesized eight kinds of aryloxides and arylamines.Part 2:13 Phenol-and amine-substituted propargylic alcohols were obtained by the reaction of aryloxide and arylamine with ethyl Grignard reagent and ketones.Part 3:12 ?'-arlyoxide-and a'-arylamine substituted ?,?-unsaturated ketones were synthesized by the Meyer-Schuster rearrangement of these propargylic alcohols using FeCl3·6H2O as the catalyst.According to the experiment,the optimal reaction conditions are as follows:acetonitrile as the solvent,20 mol%of FeCl3·6H2O as the catalyst,room temperature and 3 hours.In conclusion,we developed a convenient and efficient method for the synthesis of ?'-aryloxide-and ?'-arylamine-substituted ?,?-unsaturated ketones via Meyer-Schuster rearrangement of propargylic alcohols using inexpensive FeCl3·6H2O as the catalyst under the mild reaction conditions.