First Application on Furans: Selective control of TMS migration and its prevention

In extending the scope of this reaction the rearrangement was also tested extensively on furan derivatives. The substrates were not only subjected to migrations conditions (i.e.: warming up to ambient temperature), but also quenched with appropriate electrophiles at low temperatures. In those cases - after completion of the furan metalation - only and exclusively retained products could be obtained.

Further investigations on suitable phenyl acetylenes are now in progress, a promising preliminary result regarding the first TMS-migration on to a benzene moiety is displayed in the following scheme:



Scheme 29