1992 Fiscal Year Final Research Report Summary
Studies on the Development for New Synthetic Reagents of Organic Sulfur and Selenium Compounds and their Organization
| Project/Area Number |
02453018
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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 | University of Tsukuba |
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Principal Investigator |
FURUKAWA Naomichi TSUKUBA UNIV.,DEPT.OF CHEM.,PROFESSOR, 化学系, 教授 (80015966)
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| Project Period (FY) |
1990 – 1992
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| Keywords | Coupling Reaction / PyridylSulfoxide / Optically Active Compound / Carbanion / Thianthrene / Pentalene / Thiophene / Ring Contraction and Enlargement |
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| Research Abstract |
1.It was found that phenyl 3- and 4-pyridyl sulfoxides underwent Grignard exchange reactions to afford readily 3-and 4-pyridyl magnesium bromide which reacted with various aldehydes and ketones to give the corresponding addition products. By using this exchange reactions, optically active 3-and 4-pyridylphenyl sulfoxides were prepared. On the other hand, 2-pyridyl phenyl sulfoxide gave under similar condition to provide the ligand coupling products.i.e., 2-pyridyl derivatives in high yields. The reaction of 2-PyS(O) Ph with LDA (lithium diisopropylamide) gave highly regioselectively the 3-lithiated sulfoxide which then reacts with electrophiles to result in the formation of the 3-substituted 2-phenylsulfinyl pyridines. These pyridyl derivatives gave finally optically active 2-phenyl pyridines on treatment with Grignard reagents. Also first synthesis of optically active 2-p-tolyl pyridyl sulfoxide was performed by employing the above mentioned procedure.
2. On treatment with LDA and then with ArCHO,optically pure 2-PyCH_2S(O)-Tol-p gave a-phenyl alkoxyl substituted sulfoxides by asymmetric induction. After desulfinylation, optically active 1-aryl-2-(2-pyridyl)ethanols were synthesized.
3. Monooxides of thianthrene and selenanthrene were converted to 4,6-disubstituted derivatives by treatment with LDA and electrophiles such as (PhS)_2. Furthermore,4,6-disubstituted thianthrene and selenanthrene 1-oxides were found to react with n-BuLito give the ring contracted 1,9-disubstituted dibenzothiophenes and dibenzoselenophenes. These 1,9-disubstituted dibenzothiophenes and dibenzoselenophenes provide [3.4, bc]thienothiophene and selenophene on pyrolysis and photolysis.
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