An Efficient Photoinduced Iodoperfluoroalkylation of Carbon−Carbon Unsaturated Compounds with Perfluoroalkyl Iodides
- 8 September 2004
- journal article
- research article
- Published by American Chemical Society (ACS) in The Journal of Organic Chemistry
- Vol. 69 (20), 6658-6665
- https://doi.org/10.1021/jo0495889
Abstract
Dependent on the selection of the light sources employed, the photoinduced iodoperfluoroalkylation of a variety of unsaturated compounds takes place efficiently via a radical mechanism. Upon irradiation with a xenon lamp through Pyrex (hnu >300 nm), terminal alkenes (R-CH=CH2) and alkynes (R-C triple bond CH) undergo iodoperfluoroalkylation with perfluoroalkyl iodides (RF-I) regioselectively, providing R-CH(I)-CH2-RF and R-C(I)=CH-RF, respectively. In the case of terminal allenes (R-CH=C=CH2), the photoinduced iodoperfluoroalkylation occurs selectively at the terminal double bond, giving the corresponding beta-perfluoroalkylated vinylic iodides (R-CH=C(I)-CH2-RF) in good yields. The photoinitiated reaction of vinylcyclopropanes (c-C3H5-C(R)=CH2) with RF-I proceeds via the rearrangement of cyclopropylcarbinyl radical intermediates to the homoallylic radical intermediates, and the corresponding 1,5-iodoperfluoroalkylated products (I-(CH2)2CH=C(R)-CH2-RF) are obtained in high yields. Isocyanides (R-NC), as C-N unsaturated compounds, also undergo the xenon-lamp-irradiated iodoperfluoroalkylation to provide the corresponding 1,1-adducts (R-N=C(I)-RF) in good yields. Furthermore, the present photoinitiation procedure can be applied to the iodotrifluoromethylation of unsaturated compounds, when the xenon-lamp-irradiated reactions are conducted under the refluxing conditions of excess CF3-I.Keywords
This publication has 48 references indexed in Scilit:
- Syntheses with perfluoroalkyl radicals from perfluoroalkyl iodides. A rapid survey of synthetic possibilities with emphasis on practical applications. Part one: alkenes, alkynes and allylic compoundsJournal of Fluorine Chemistry, 1999
- Generation and Synthetic Utilization of Highly Reactive Fluorinated Intermediates.Journal of Synthetic Organic Chemistry, Japan, 1997
- Free‐Radical Carbonylations: Then and NowAngewandte Chemie, 1996
- Reaction of Perfluoroalkyl Iodides with Electron-Deficient Olefins under UV IrradiationThe Journal of Organic Chemistry, 1995
- Synthetic Blocks for Organofluorine Compounds : Chemistries of Trifluoroacetimidoyl HalidesJournal of Synthetic Organic Chemistry, Japan, 1995
- N-Substituted 2,2,2-trifluoroethanimidic acid 1-methylethylidene hydrazides as synthetic blocks for trifluoromethylated nitrogen heterocycles: syntheses and oxidative cyclizationsThe Journal of Organic Chemistry, 1992
- Photochemical addition of perfluoro-n-butyl iodide to alkynes and olefinsJournal of Fluorine Chemistry, 1991
- Recent Advances in Trifluoromethylation.Journal of Synthetic Organic Chemistry, Japan, 1991
- Kinetics and regioselectivity of ring opening of substituted cyclopropylmethyl radicalsThe Journal of Organic Chemistry, 1989
- Rate constants and Arrhenius parameters for the reactions of primary, secondary, and tertiary alkyl radicals with tri-n-butyltin hydrideJournal of the American Chemical Society, 1981