1989 Fiscal Year Final Research Report Summary
Development of Highly Stereoselective Carbon-Carbon Bond Forming Reactions
| Project/Area Number |
63470018
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
有機化学一般
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| Research Institution | Science University of Tokyo |
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Principal Investigator |
MUKAIYAMA T. Science Univ. of Tokyo, Fac. of Sci., Prof, 理学部, 教授 (60016003)
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| Project Period (FY) |
1988 – 1989
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| Keywords | chiral diamine / tin(II) enolate / aldol reaction / Michael reaction / 1,2-cis Ribofuranoside / tin(II) triflate / diphosphonium salt / Prins-type reaction |
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| Research Abstract |
New synthetic methods for highly stereoselective carbon-carbon bond formations have been developed.
1. In the presence of trimethylsilyltriflate, chiral diamine coordinated tin(II) enolates react with alpha,beta-unsaturated ketones to afford the corresponding Michael adducts in good ees. This reaction is applied to the catalytic asymmetric Michael reaction of tin(II) enethiolates with alpha,beta-unsaturated ketones.
2. Acetals smoothly react with activated or simple 1,1-di-substituted olefins to give the corresponding adducts in the coexistence of catalytic amounts of trimethylsilyl chloride (trityl-chloride) and tin(II) chloride with a stoichiometric amount of lithium perchlorate. Aldehydes also react with the olefins to form the Prins-type reaction products by further addition of alkoxy trimethylsilane to the above catalyst system.
3.1,2-cis-Ribofuranosides are stereoselectively prepared in high yields by the reaction of 1-0-acetyl-beta-D-ribose with silylated nucleophiles by the promotion of a new catalyst system, the combined use of a catalytic amount of tin(IV) chloride and tin(II) triflate with a stoichiometric amount of lithium perchlorate.
4. In the presence of a catalytic amount of diphosphonium salt, aldol reaction of silyl enol ethers with aldehydes or acetals and the Michael reaction of silyl enol ethers with alpha,beta-unsaturated ketones or acetals smoothly proceed to produce the corresponding adducts in fairly good yields. Imines also react with ketene silyl acetals to give the corresponding beta-aminoesters in good yields in the presence of the above catalyst.
5. In the presence of a catalytic amount of (Rh(COD)Cl)_2, trimethyl cyanide reacts with acetals derived from aliphatic, unsaturated or aromatic aldehydes to form the corresponding alpha-cyano derivatives of [Rh(COD)Cl]_2 and trimethylsilyl cyanide, silyl enol ethers also react with acetals to yield the corresponding aldol adducts under almost neutral conditions.
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