Synthesis of ortho-perfluoroalkyl phenones from hemifluorinated enones as key building blocks
摘要:
The title compounds are prepared by cycloaddition of perfluoroalkenyl ketones and 1,3-dienes, with a subsequent aromatization by basic dehydrofluorination. The perfluoroalkenyl ketones were prepared by the reaction of perfluoroorganometallic reagents with acylsilanes. The transformation may be performed more efficiently in a simplified process without purification of the intermediate cycloadducts. The overall methodology is an interesting entry to ortho-perfluoroalkyl phenones with the possibility to vary the substitution at the acyl and on the ring moiety. (c) 2006 Elsevier Ltd. All rights reserved.
Mixed organofluorine-organosilicon chemistry. 3. A highly efficient and convenient synthesis of aryl perfluoroalk-1-enyl ketones from perfluoroalkyl iodides and aroylsilanes
摘要:
A one-pot procedure is described to synthesize aryl perfluoroalkenyl ketones with high yields from perfluoroalkyl iodides and aroylsilanes. It consists of conversion of the iodide to the perfluoroorganomagnesium bromide followed by reaction with the aroylsilane, in ether, at low temperatures (-45-degrees-C). Warming to room temperature and addition of triethylamine accelerate the process leading quantitatively to the enones, which can be isolated in the pure E-configuration. The mechanism of this synthesis, involving a Brook rearrangement, is discussed. An alternative procedure is proposed to synthesize the same enones, with equivalent efficiency, from 1-aryl-1-(trimethylsilyl)perfluoroalkan-1-ols.
Perfluoroalkenyl ketones, obtained by reaction of perfluoroorganometallic reagents with acylsilanes, are shown to be versatile dienophiles in Diels–Alder reactions with various dienes.
Intra–Intermolecular Criss-cross Cycloaddition of Nonsymmetrical Allenylazines with Fluorinated Enones as an Initial Step in the Synthesis of4H-Pyrrolo[1,2-b]pyrazoles
Nonsymmetricalallenylazines undergo in boiling xylene intramolecular cycloaddition via formation of an unstable 1,3-dipole, which reacts with an added dipolarophile. In this paper we pay attention to the first intra-intermolecularcriss-crosscycloaddition with a fluorinatedenone. Although the expected products with three fused heterocycles were not isolated, new bicyclic products were found and
The title compounds are prepared by cycloaddition of perfluoroalkenyl ketones and 1,3-dienes, with a subsequent aromatization by basic dehydrofluorination. The perfluoroalkenyl ketones were prepared by the reaction of perfluoroorganometallic reagents with acylsilanes. The transformation may be performed more efficiently in a simplified process without purification of the intermediate cycloadducts. The overall methodology is an interesting entry to ortho-perfluoroalkyl phenones with the possibility to vary the substitution at the acyl and on the ring moiety. (c) 2006 Elsevier Ltd. All rights reserved.
Mixed organofluorine-organosilicon chemistry. 3. A highly efficient and convenient synthesis of aryl perfluoroalk-1-enyl ketones from perfluoroalkyl iodides and aroylsilanes
作者:Boniface Dondy、Charles Portella
DOI:10.1021/jo00076a028
日期:1993.11
A one-pot procedure is described to synthesize aryl perfluoroalkenyl ketones with high yields from perfluoroalkyl iodides and aroylsilanes. It consists of conversion of the iodide to the perfluoroorganomagnesium bromide followed by reaction with the aroylsilane, in ether, at low temperatures (-45-degrees-C). Warming to room temperature and addition of triethylamine accelerate the process leading quantitatively to the enones, which can be isolated in the pure E-configuration. The mechanism of this synthesis, involving a Brook rearrangement, is discussed. An alternative procedure is proposed to synthesize the same enones, with equivalent efficiency, from 1-aryl-1-(trimethylsilyl)perfluoroalkan-1-ols.