Acceleration of alkenyltrimethylsilane fluorination under mild conditions using ultrasound

Alkenyltrimethylsilanes are selectively fluorodesilated to alkenyl fluoride very readily by reaction with 1-chloromethyl-4-fluoro-1,4-diazoniabicyclo[2,2,2]octane bis-tetrafluoroborate (Selectfluor) and N-fluorobenzensulfonimids at room temperature under ultrasound. In the presence of ultrasound irradiation in the case atone of the reactions, the yield was 85% after 25 min, but using the previously established thermal method the yield was only 32% after 20 h. Crown Copyright (C) 2010 Published by Elsevier B.V. All rights reserved.