Tin Powder Mediatedd One-pot Synthesis Of ?-Trifluoromethyl-?-acylhydrazinyl Carbonyl Compounds

Trifluoromethyl containing organic compounds have been extensively applied in pharmaceuticals,agrochemicals and materials in recent years.There are two main ways to introducing trifluoromethyl group into organic molecules:direct trifluoromethylation and trifluoromethyl building block synthesis.The trifluoromethyl building block method has the advantages of good selectivity,mild condition and high yield.On the other hand,N-acylhydrazines are also one of the most important compounds in organic synthesis,and have been widely used in pesticide,pharmaceuticals,materials science and so on.Especially,trifluoromethylated N-acylhydrazines compounds were shown to be anticancer activity.Therefore,it is of great theoretical and practical significance to explore the synthesis of hydrazide-containing hydrazide compounds.So we explored the tin power-promoted"one-pot" synthesis ?-trifluoromethyl-?-hydrazines-based carbonyl compounds.It is a supplement and improved method for the synthesis trifluoromethyl-hydrazine compounds.The thesis includes four chapters:Chapter one:Research progress in Reformatsky-type reactionIn this chapter,we discussed the development and application research of Reformasky reaction in organic synthesis.The first part:zinc and its salts mediated Reformatsky reaction;the second part:other metals and their salts mediated Reformatsky reaction;the third part:the study of Reformasky reaction in aqueous phase.Chapter two:Tin powder-mediated "one-pot" preparation of?-trifluoromethyl-?-acylhydrazinyl carbonyl compoundsThe "one-pot" reactions of trifluoroacetaldehyde methyl hemiacetal with hydrazides,tin powder and ethyl bromoacetate were studied and a series of?-trifluoromethyl-?-acylhydrazine esters or ketones were synthesized with high yields.It was found that stannanes can be easily obtained in situ from a-ethyl bromoacetates and tin powder,which can carry out reformatsky-type reaction with N-acylhydrazones condensed from N-acylhydrazines and trifluoroacetaldehyde methyl hemiacetal.The method further extends the application of tin in organic synthesis.The results show that both aliphatic and aromatic hydrazide can be used in this reaction.At the same time,we found that boron trifluoride ether can be a good activation of trifluoromethyl acylhydrazone and can promote the Reformatsky-type reaction.The resulting?-trifluoromethyl-?-acylhydrazine esters or ketones compound provides feedstock support for its future drug activity assays and is expected to be useful in scientific research in medicine and pesticides.Chapter three:Base-promoted "one-pot" reaction of trifluoroacetaldehyde methyl hemiacetal,hydrazide and acetophenoneThe chapter explores the synthesis of trifluoromethyl 1,5-dicarbonyl compounds from N-acylhydrazones,which were condensed from N-acylhydrazines and trifluoroacetaldehyde methyl hemiacetal,with acetophenone under base condition.It provides a new approach for the synthesis of trifluoromethyl 1,5-dicarbonyl compounds.The method has potential industrial application prospects.