| Budget Amount *help |
¥2,100,000 (Direct Cost: ¥2,100,000)
Fiscal Year 1994: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1993: ¥1,500,000 (Direct Cost: ¥1,500,000)
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| Research Abstract |
We investigated the preparation and synthetic utilization of the fluorinated vinamidinium (1,5-diaza-1,3-pentadienium) salts, which have the potential of serving as fluorinated and conjugated three-carbon building blocks in organic synthesis.
1. Preparation of fluorinated vinamidinium salts :
We Prepared the beta-fluorovinamidinium salt (1) having various substituents on nitrogen by our previously developed method. We also tried the preparation of another fluorinated vinamidinium salt (2) by the new reaction of N- (2,3,3,4,4,5,5-heptafluoro-1-pentenyl) trimethylammonium iodide with dialkylamines.
2. Investigation on the utilization of beta-fluorovinamidium salt as synthon :
(1) The reactions of beta-fluorovinamidinium salt (1) with bifunctional nitrogen-nucleophiles (amidines, hydrazines) easily gave the corresponding monofluorinated heterocycles (5-fluoro-pyrimidines, 4-fluoropyrazoles) in good yields. (2) The reactions of 1 with enolates proceeded smoothly to afford multifunctionalized dienaminone derivatives having fluoro-substituent. (3) Although the existence of 2 as intermediate in the reaction described above was confirmed, its isolation was unsuccessful. However, when the reaction mixture was treated with water, fluorinated alpha, beta-unsaturated aldehydes and ketones were obtained. The treatment with methylhydrazine instead of water produced the corresponding pyrazole.
Present studies showed that fluorovinamidinium salts were very useful synthon to introduce fluorinated C3 unit into substrates. We also developed new facile and efficient method for synthesis of organofluorine compounds such as fluorinated heterocycles and dienaminones.
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