Smi < Sub > 2 < / Sub > Promote Intramolecular Class Which Alcohol Coupling Reaction Research And Coumarone Compounds Synthesis

The dissertation focused on the research about samarium diiodide (SmI2) promoted intramolecular reduction Pinacol-Coupling reactions and the high efficient synthesis of benzofuran substituted α,β-unsaturated esters.The first part of this dissertation based on the research about asymmetric synthesis of novel vicinal amino alcohols via intramolecular sulfinimine-ketone pinacol-type reductive coupling promoted by SmI2. A series of1-amino-1,2,3,4-tetrahydro-naphthalen-2-ols were obtained in modest to good yields with excellent ee and high dr. It was found that up to99:1dr value was obtained by sulfinimine reacting with aryl substituted ketone whereas the dr value was decreased by the decreasing group when alkyl substituted ketone was employed. The absolute configuration was determined by X-ray diffraction. Via this method, a new product indan-l-amino-2-ol was obtained in80%yield with up to99:1ee value. Also, we investigated the intramolecular disulfinimines asymmetric pinacol coupling reaction. Unfortunately, high yield and dr value was obtained only by the methyl substituted group while other substrates would make the reaction system complex, thus poorer dr value was obtained.In the second part, samarium diiodide promoted intramolecular elimination-pinacol-coupling reaction to prepare allyl-1,2-diols was presented. A series of novel vinyl-1,2-diols were obtained via self-diminished and pinacol-coupling process catalyzed by samarium diiodide in modoest to good yields. It was found that phenyl group with electron-withdraw-group would lower the yield by the substrates extension. Meanwhile we investigated the cross coupling of chalcone and alkyl acetone induced by SmI2. Unluckily, lower yield and a couple of side reactions were obtained in comparison to the intramolecular elimination-pinacol-coupling reaction. It is known that ether can be obtained by salicylic aldehyde reacting with methyl bromocrotonate under low temperature in the presence of base, however, benzofuran substituted α, β-unsaturated esters was obtained when the reaction system was heating. Further research showed that similar reaction also could work when salicylic acetone was employed. We tried to synthesize other heterocyclic compounds via this methodology as well, but the result was not too good.