1997 Fiscal Year Final Research Report Summary
Cationic Palladium Complex-Catalyzed Hetero Diels-Alder Reaction
| Project/Area Number |
08651015
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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 | Tohoku University |
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Principal Investigator |
OI Shuichi Tohoku University, Graduate School of Engineering, Department of Materials Chemistry, Lecturer, 大学院・工学研究科, 講師 (00241547)
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| Project Period (FY) |
1996 – 1997
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| Keywords | palladium complex / hetero Diels-Alder reaction / asymmetric reaction / dihydropyran |
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| Research Abstract |
The hetero Diels-Alder reaction using carbonyl compounds as dienophiles has been a very useful method to construct the dihydropyran skeleton. However, it is necessary to use activated dienes containing strong electron-donating groups and/or activated carbonyl compounds containing electronwithdrawing groups to conduct the reaction smoothly under mild conditions. In this research project, we found that the hetero Diels-Alder reaction of nonactivated simple dienes with aldehydes is catalyzed by cationic palladium (II) complexes. Thus, the reaction of 2-methyl and 2,3-dimethyl substituted 1,3-butadienes with aromatic and aliphatic aldehydes proceeded smoothly at 50ﾟC for 20 h in the presence of 2 mol% of the cationic palladium (II) complexes, such as [Pd (dppp) (PhCN) _2] (BF_4) _2. In this reaction, we assume that the palladium complex acts as a Lewis acid catalyst. In the research of 1997, we investigated asymmetric hetero Diels-Alder reaction using chiral palladium complex. The reaction of phenylglyoxal with 2,3-dimethyl-1,3-butadiene, 1,3-cyclohexadiene, and 1,2-dimethylenecyclopentane in the presence of [Pd (S-BINAP) (PhCN) _2] (BF_4) _2 afforded the cyclization products in 95 to 99 %ee, respectively. It can be assumed that chelate coordination of the two carbonyl group of phenylglyoxal to palladium give rise to the high enantioselectivity.
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