| Budget Amount *help |
¥3,100,000 (Direct Cost: ¥3,100,000)
Fiscal Year 2000: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1999: ¥2,400,000 (Direct Cost: ¥2,400,000)
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| Research Abstract |
Fluorine compounds have been useful intermediates for organic synthesis in recent years. However, many difficulties in treating the F atom within theoretical method prevent the method from widely use for investigating mechanism of reactions with the atom. In the present study, we used ab intio molecular orbital calculations as well as the Density Functional theory, whose efficiency for the fluorine compounds was proved recently, were used to calculate physico-chemical property and the reaction mechanisms of unique fluorine compounds. We performed following investigations (1) A new usage of DAST for selective methylation of 2-hydroxypyrimidine using trimethyl-silyldiazomethane, (2) Theoretical Study of Fluorination mechanism of 2-hydroxy-3-phenylalkinate with DAST,(3) Ab initio Molecular orbital study on three feasible mechanisms for substitution of the vinyl carbon in F_2C=C(OMs)BMe_3^-, (4) Ab initio molecular orbital study on substitution on the vinylic carbon in F_2C=C(OMs)BMe_3^- under S_N1-like mechanism. The former two studies intended to prove unique properties of DAST(diethylaminosulfur hifluoride), a famous fluorination reagent. The Density Functional calculations showed that the reaction of DAST and H_2O produces a strong acid which is the key for selective methylation of 2-hydroxypyrimidine. The latter two were dedicated to clarify the mechanisms of substitution reactions on the sp^2 carbon in a fluorine compound, F_2C=C(OMs)BMe_3^-. The present study achieved the initial purpose sufficiently.
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