Sonochemical fluorination of heterocyclic nitro compounds with Selectfluor™ (F-TEDA-BF4)
摘要:
CH and CH2 groups attached to a heterocycle and a nitro function were rapidly mono- or difluorinated by reaction with 1-chloromethyl-4-fluoro-1,4-diazoniabicyclo[2,2,2]octane bis-tetrafluoroborate (Selectfluor) in the presence of 1,8-diazabicyclo [5.4.0]undec-7-ene (DBU), preferably with Ultrasonic irradiation. (c) 2006 Elsevier Ltd. All rights reserved.
Fluorination and chlorination of nitroalkyl groups
摘要:
Heterocycles substituted with a nitromethyl (CH2NO2) or phenyl-nitromethyl (CHPhNO2) group were prepared by reaction of a methyl- or phenylmethyl-substituted heterocycle, respectively, with lithium di-isopropylamide followed by quenching the intermediate carbanion with methyl nitrate. Conversion of CH2NO2 attached to an alkyl or aryl moiety into a dichloronitromethyl (CCl2NO2) group was achieved using N-chlorosuccinimide and 1,8-diazabicyclo[5.4.0] undec-7-ene (DBU) in dichloromethane. Similarly, CH2NO2 attached to an alkyl or aryl group was converted into difluoronitromethyl (CF2NO2) using either 1-chloromethyl-4-fluoro-1,4-diazoniabicyclo[2.2.2]octane bis( tetrafluoroborate) (Selectfluor (TM)) or N-fluorobenzenesulfonimide with DBU as base and dichloromethane as solvent. Reaction of omega-nitroacetophenone with Selectfluor/DBU in dimethylformamide followed by acidification and distillation gave the parent difluoronitromethane in a useful 'one-pot' procedure. (c) 2007 Elsevier Ltd. All rights reserved.
Sonochemical fluorination of heterocyclic nitro compounds with Selectfluor
作者:Majid M. Sadeghi、Hossein Loghmani-Khouzani、Reza Ranjbar-Karimi、Philip Butler、Bernard T. Golding
DOI:10.1016/j.tetlet.2006.03.144
日期:2006.6
Fluorination and chlorination of nitroalkyl groups
作者:Philip Butler、Bernard T. Golding、Gilles Laval、Hossein Loghmani-Khouzani、Reza Ranjbar-Karimi、Majid M. Sadeghi
DOI:10.1016/j.tet.2007.08.020
日期:2007.11
Heterocycles substituted with a nitromethyl (CH2NO2) or phenyl-nitromethyl (CHPhNO2) group were prepared by reaction of a methyl- or phenylmethyl-substituted heterocycle, respectively, with lithium di-isopropylamide followed by quenching the intermediate carbanion with methyl nitrate. Conversion of CH2NO2 attached to an alkyl or aryl moiety into a dichloronitromethyl (CCl2NO2) group was achieved using N-chlorosuccinimide and 1,8-diazabicyclo[5.4.0] undec-7-ene (DBU) in dichloromethane. Similarly, CH2NO2 attached to an alkyl or aryl group was converted into difluoronitromethyl (CF2NO2) using either 1-chloromethyl-4-fluoro-1,4-diazoniabicyclo[2.2.2]octane bis( tetrafluoroborate) (Selectfluor (TM)) or N-fluorobenzenesulfonimide with DBU as base and dichloromethane as solvent. Reaction of omega-nitroacetophenone with Selectfluor/DBU in dimethylformamide followed by acidification and distillation gave the parent difluoronitromethane in a useful 'one-pot' procedure. (c) 2007 Elsevier Ltd. All rights reserved.
Sonochemical fluorination of heterocyclic nitro compounds with Selectfluor™ (F-TEDA-BF4)
作者:Majid M. Sadeghi、Hossein Loghmani-Khouzani、Reza Ranjbar-Karimi、Bernard T. Golding
DOI:10.1016/j.tetlet.2006.01.037
日期:2006.4
CH and CH2 groups attached to a heterocycle and a nitro function were rapidly mono- or difluorinated by reaction with 1-chloromethyl-4-fluoro-1,4-diazoniabicyclo[2,2,2]octane bis-tetrafluoroborate (Selectfluor) in the presence of 1,8-diazabicyclo [5.4.0]undec-7-ene (DBU), preferably with Ultrasonic irradiation. (c) 2006 Elsevier Ltd. All rights reserved.