Preparation and Synthetic Application of Fluorinated Vinamidinium Salts as Building Unit for Synthesis of Organofluorine Molecules

本文研究了氟化维脒（1,5-二氮-1,3-戊二烯）盐的制备及其在有机合成中的应用，该盐具有作为氟化和共轭三碳基的潜力。氟化维酰胺盐的制备：我们用我们以前发明的方法制备了在氮上有多种取代基的-氟维酰胺盐(1)。我们还尝试用N-（2,3,3,4,4,5,5-七氟-1-戊基）三甲基碘化铵与二烷基胺的新反应制备另一种氟化氨基盐(2)。利用-氟维酰胺盐作合成体的研究：(1)-氟维酰胺盐(1)与双官能团亲氮核试剂（脒类、肼类）反应，可得到相应的单氟杂环（5-氟嘧啶类、4-氟吡唑类），产率高。(2) 1与烯醇酯的反应顺利进行，得到了含氟取代基的多功能化二胺酮衍生物。(3)虽然证实了2作为中间体存在于上述反应中，但未能成功分离。然而，当反应混合物与水处理时，得到氟化的α、β不饱和醛和酮。用甲基肼代替水处理产生相应的吡唑。目前的研究表明，氟维酰胺盐是将氟化C3单元引入底物的非常有用的合成物。我们还开发了合成氟化杂环和二胺酮等有机氟化合物的简便、高效的新方法。

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.