| Project/Area Number |
12650842
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Synthetic chemistry
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| Research Institution | HOKKAIDO UNIVERSITY |
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Principal Investigator |
ISHIYAMA Tatsuo Hokkaido Univ., Grad. School of Eng., Asso. Prof., 大学院・工学研究科, 助教授 (00232348)
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| Co-Investigator(Kenkyū-buntansha) |
YAMAMOTO Yasunori Hokkaido Univ., Grad. School of Eng., Inst., 大学院・工学研究科, 助手 (30271646)
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| Project Period (FY) |
2000 – 2001
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| Project Status |
Completed (Fiscal Year 2001)
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| Budget Amount *help |
¥3,200,000 (Direct Cost: ¥3,200,000)
Fiscal Year 2001: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 2000: ¥2,300,000 (Direct Cost: ¥2,300,000)
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| Keywords | Allylic Boron Compounds / Transition Metal Catalysts / Diborons / Allylic Electrophiles / Homoallylic Alcohols / 3-Alkoxyvinylboranes / Cyclic Ethers / クロスカップリング反応 / 二重結合異性化反応 |
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| Research Abstract |
1. Nucleophilic Borylation Reactions of Allylic Electrophiles with Diborons
(1) Nucleophilic borylation reactions of allylic acetates or halides with bis(pinacolato)diboron regio-and stereoselectively proceeded at 50 degree when using a combination of Pd(dba)2/DMSO or Pd(dba)2-2AsPh3/KOAc/toluene to afford allylic boron compounds in excellent yields. The reactions also tolerated various functionalities such as carbonyl groups. A catalytic cycle may involve oxidative addition of the allylic electrophile to a palladium(0) complex, transmetalation between the diboron and a palladium(II) intermediate, and reductive elimination of the allylic boron compound.
(2) Three-component reactions of bis(pinacolato)diboron, allylic acetates, and aldehydes smoothly occurred under the conditions optimized above (Pd(dba)2/DMSO/50 degree), resulting in high yields of acyclic homoallylic alcohols. Sequential reactions, involving nucleophilic borylation of allylic acetates substituted by a carbonyl group in the presence of a Pd(dba)2-2AsPh3 catalyst in toluene at 50 degree and intramolecular allylboration at 100 degree provided cyclic homoallylic alcohols in high yields with high cis-stereoselectivity.
2. Synthesis of Allylic Boron Compounds via Transition Metal-Catalyzed Isomerization Reactions of 3-Alkoxyvinylboranes
(1) Isomerization reactions of 3-alkoxyvinylboranes stereoselectively proceeded in the presence of [Ir(COD)(PPh2Me)2]PF6 and NiC12(PPh2Me)2 catalyst to give E- and Z-allylic boron compounds, respectively.
(2) 3-Alkoxyvinylboranes having a carbonyl functionality underwent the catalytic isomerization followed by intramolecular allylboration to give cyclic ethers in good yields.
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