A rhodium-catalyzed heterocycloaddition route to 5-fluoroalkyl substituted 1,3-oxazoles
摘要:
In the presence of catalytic rhodium (II) acetate, ethyl 2-diazo-fluoroalkylacetoacetate, obtained from the reaction of ethyl fluoroalkylacetoacetate with perfluoroalkanesulfonyl azide or tosyl azide, reacted readily with nitriles to give a series of 5-fluoroalkyl substituted 1,3-oxazoles in fair to good yields. (C) 2000 Elsevier Science S.A. All rights reserved.
在本文中,我们报告了24种新的F-烷基-4香豆素及其合成中间体,即相应的F-烷基β-酮酯的合成和光谱特征。反应产率取决于原料和环化剂的性质。在每种化合物中都指定了1 H和19 F NMR化学位移和耦合常数,并且观察到了一种新型的长距离HF耦合常数5 J,并通过几何,空间和电子效应将其解释为通过空间耦合。
Reaction du carboéthoxyméthylènetriphénylphosphorane sur les F-nitriles : une nouvelle voie d'accès aux β-cétoesters perfluoroalkyles
作者:H. Trabelsi、E. Rouvier、A. Cambon
DOI:10.1016/s0022-1139(00)81436-0
日期:1986.4
We report a new method for the preparation of F-alkyl β-ketoesters from F-nitriles. This method has several advantages over the usual approach, namely quantitative yields, intermediate formation of F-alkyl iminophosphoranes which are useful in other syntheses and convenient preparation of a range of new carbonyl compounds.
A simple synthesis of fluoroalkyl substituted dihydrofurans by rhodium(II)-catalyzed 1,3-dipolar reactions
作者:Yanli Wang、Shizheng Zhu
DOI:10.1016/s0040-4020(01)00183-1
日期:2001.4
The rhodium(II)-catalyzed reactions of ethyl 2-diazo-fluoroalkylacetoacetate 1 with vinyl ethers have been studied. The reactions of 1a-e with isobutyl vinyl ethers afforded dihydrofuroates 3a-e in good to excellent yields. Further transformation of the dihydrofuroates by acid-catalyzed alcohol elimination could give alpha -fluoroalkyl-beta -furoates readily. Similarly, stable diazo compounds 1a and b reacted with cyclic vinyl ethers to give 1,3-dipolar cycloaddition products. Interestingly, only vinyl C-H insertion compound was obtained concerning the reaction of la with 2,5-dimethylfuran. The reaction mechanism was also discussed. (C) 2001 Elsevier Science Ltd. All rights reserved.
Synthesis of oxetanes with perfluorinated-alkyl substituents
作者:Marion Lanier、Raphael Pastor、Jean G. Riess
DOI:10.1016/s0040-4039(00)60684-6
日期:1993.8
Perfluoroalkylated oxetanes have been obtained exclusively, in 36% yield, by reduction of perfluoroalkylated beta-ketoester, followed by iodination and dehydroiodination.
Synthese et etude spectrale de F-alkyl-4 coumarines
作者:V. Bayer、R. Pastor、A. Cambon
DOI:10.1016/s0022-1139(00)82207-1
日期:1982.4
In this paper, we report synthesis and spectral characteristics of 24 new F-alkyl-4 coumarins and their synthetic intermediates, the corresponding F-alkyl β-keto esters. The reaction yields depend on the nature of the starting materials and the cyclisation agents. 1H and 19F N.M.R. chemical shifts and coupling constants are assigned in every compound and a new kind of long distance H-F coupling constant
在本文中,我们报告了24种新的F-烷基-4香豆素及其合成中间体,即相应的F-烷基β-酮酯的合成和光谱特征。反应产率取决于原料和环化剂的性质。在每种化合物中都指定了1 H和19 F NMR化学位移和耦合常数,并且观察到了一种新型的长距离HF耦合常数5 J,并通过几何,空间和电子效应将其解释为通过空间耦合。