Development of Bismuth Compounds as A Organic Synthetic Reagent and It's Application to New Synthetic Reactions

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Organic synthesis by using bismuth is described as follows.1. Esterification Reaction Using Tributylbismuthine : Under an oxygen atmosphere, tributylbismuthine reacted with acid chlorides or carboxylic acids to give the corresponding butyl carboxylates in good yields.2. Catalytic Bismuth Triflate Promoted Stereoselective Aldol Reaction : In the presence of a catalytic amount of bismuth triflate, silyl enol ethers react with aldehydes to give the corresponding aldols in good yields. When the silyl enol ether of propiophenone was reacted with aldehydes, erythro aldol products were obtained stereoselectively. Asymmetric aldol reaction by chiral diethyl tartrate-bismuth triflate gave the product in low optical yield(only 12%ee).3. Reaction of Propargyl Bromide with Aldehydes in the Presence of Metallic Bismuth : In the presence of metallic bismuth, propargyl bromide reacted with aldehydes to give a mixture of the allen derivatives and acetylene derivatives.4. Synthesis of beta-Aminoalcohols by Bismuth Trichloride Mediated Aminolysis of Epoxides : In the presence of bismuth trichloride, epoxides reacted with aromatic amines to give the corresponding beta-aminoalcohols.5. Enantioselective Trimethylsilylcyanation of Aldehydes Catalyzed by Chiral Bismuth Compound : A variety of aldehydes were trimethylsilylcyanated in quantitative yields with bismuth trichloride or bismuth triflate. 2-Hydroxy-2-phenylacetonitrile was obtained in 58% ee with a catalyst prepared in situ from chiral diethyl tartrate, butyllithium, and bismuth trichloride.6. Synthesis of Pyran Derivatives from Allyltrimenthylsilane and Aldehydes in the Presence of Bismuth Trichloride : In the presence of bismuth trichloride, allyltrimenthylsilane reacted with 2 equivalents of aldehydes to afford pyran derivatives.7. Allylation of lmines by Using Bismuth Trichloride-Metallic Zinc : Allyl bromide reacted with imines to give the corresponding homoallylamines in the presence of bismuth trichloride-metallic zinc.