Study On "one Pot" Allylation Reaction Of Aldehydes Mediated By Indium

As important organic synthesis intermediates, homoallyl alcohols andhomoallyl alcohol esters have important applications in the synthesis ofmedicines, pesticides and natural products, especially in the synthesis ofsome biological active molecules, such as macrolides, polyhydroxylatednature products, and polyether antibiotics. In particular, for the synthesisof homoallyl alcohol esters, the simultaneous addition and esterificationin one reactor can simplify the operational procedure to improve thesynthetic efficiency and to obtain high yields of the products. In thisthesis, the allylation reaction and allylation-esterification reaction ofaldehydes mediated by indium are studied in detail. The synthsis ofhomoallyl alcohols are conducted in pure THF as well as in THF aqueous.An efficient, one-pot, three component protocol is also developed forsimultaneous allylation-esterification of aldehydes by using allyl bromideand acylation reagents.This thesisincludesthree chapters:Chapter 1: Indium reagents-mediated reactions and the applications inorganic synthesis.In this section , the organic reactions mediated by indium metal,indium salt and organoindium reagents in recent years are reviewed. Thereactions involve allylation reaction, propargylation reaction, Diels-Alderreaction, Aldol condensation and coupling, etc. In particular, the newtypes and the advantages of indium reagents-mediated reactionsintroduced, the applications of other reageats and reaction in organicsynthesis are also described.Chapter 2:Indium-mediated one-pot synthesisof homoallyl alcohols In this section, two solvent systems, pure THF and THF aqueous, areused and contrasted for the synthesis of homoallyl alcohols from Barbier-type allylation reaction of aldehydes with allyl bromide mediated byindium. Twenty-seven products are obtained in high yields under mildconditions. The results show that the allylation of aldehydes in pure THFis inferior to the reaction in THF aqueous.An activator, TMSCl, is neededand the scope of substrates is limited to aromatic aldehydes in pure THF.On the contrary, the allylation reactions in THF aqueous afford 91%-97%yields of homoallyl alcohols, which show some advantageous,such asshort reaction times, excellent yields, small amount of solvents and widescope of substrates, in comparison with the reactions in pure THF and inwater.Chapter 3: Indium-mediated one-pot, three component synthesis ofhomoallyl alcoholestersA convenient and efficient one-pot three-component protocol for thesynthesisof homoallylalcoholestersmediated by indium using aldehydes,allyl bromide and acylation reagents is described in this section. Whenacyl chlorides are used as acylation reagents, nine products of homoallylalcohol esters are abtained with yields of 51%-92%. However, whenanhydrides are used, fourteen productds are afforded in 91%-96% ofyields. It is noted that aliphatic acylation reagents have higher reactivitiesthan those of aromatic ones, and that aliphatic aldehydes and heterocyclicaromatic aldehydes have lower reactivities than aromatic aldehydes,which might be due to the electron effect and steric hindrance ofsubstituents. The advantages of this method include easy workup,excellent yields, short reaction times, no use of catalystsand dehydrants.