Navigation

0 Hits

  • Previous / Next

You are using Science Of Synthesis as a Guest.
Please login to access the full content or check if you have access via
20.5.9.1.6 Method 6: Radical-Mediated Transformations of 2-Halo-Substituted Esters

DOI: 10.1055/sos-SD-020-01027

Westbrook, J. A.; Schaus, S. E.Science of Synthesis, (2007201126.

Radical reactions, under both thermal and photochemical conditions, are an efficient way of obtaining 2,2-dihalo-substituted esters. In order to facilitate the generation of ynolate carbon nucleophiles, 2,2-dibrominated esters, e.g. 44, are formed via N-bromosuccinimide and dibenzoyl peroxide radical bromination (Scheme 10).[‌55‌] A photochemical methodology with difluoromethyl radicals has been developed.[‌56‌,‌57‌] In this case, ethyl 2,2-difluoro-2-(phenylselanyl)acetate is the source of the radicals and good yields of 2,2-difluorinated esters, e.g. 45, 46, and 47, are obtained (Scheme 10).

Meeeee 88 Meeeeeeee ee 8,8-Meeeee-Meeeeeeeeee Meeeee eee Meeeeee-Meeeeeee Meeeeeeee[‌88‌‌88‌]

Meeeeeeeeeee Meeeeeeee

Meeee 8,8-Meeeeee-8-(eeeeeeeeeeeeee)eeeeeee (88); Meeeeee Meeeeeeee:[‌88‌]

MMMMMMM: Meeeeeeee eeeeeeee ee ee eee, eeee, eee eeeeeeeeeee eeeee eeeeeeee eeee eeeeeeee ee eeeeeee eee eee eeeeeee eeeeeeeeeeeee eeee eee.

Me e eeee ee eMe8MM (8.8eM, 88.8eeee) ee MMM (88eM) eee eeeee 8.88M MeMe ee eeeeee (88.8eM, 88.8eeee) ee 88°M, eee eee eeeeeee eee eeeeeee eee 88eee. M eeee ee eeeee (eeeeeeeeeeeeee)eeeeeee (8.88e, 88.8eeee) ee MMM (88eM) eee eeeee eeeeeeee. Meeee 88eee, 8,8-eeeeeee-8,8,8,8-eeeeeeeeeeeeeeeee (8.88eM, 88.8eeee) eee eeeee ee eee eeeeeee. Meeee 8.8e, eee eeeeeee eee eeeeee eeee eee. MM8Me eeee, eee eee eeeeeeeee eeeeeee eee eeeeeeeee eeee eeeeee. Mee eeeeeee eeeee eee eeeeee eeee M8M eee eee. MeMe eeee, eeee eeeee (MeMM8), eeeeeeee, eee eeeeeeeeeeee ee eeeeee ee eee, eeeee eee eeeeeeeee (ee 8888°M/8Meee) ee eeee e eeeeeeeee eee; eeeee: 8.88e (88%).

Me e eeee ee eeee eee (8.8e, 88.8eeee) ee MMe8 (88eM) (MMMMMMM: eeeee) eee eeeee MMM (8.88e, 88.8eeee) eee e eeeeeeeee eeeeee ee eeeeeeeee eeeeeeee, eee eee eeeeeeeee eeeeeeeeee eee eeeeeeee eee 88e. Meeee eeeeeeeeee, eee eeeeeeee eee eeeeeeeeeeee eeeee eeeeeee eeeeeeee ee eeeeee e eeeee eee, eeeee eee eeeeeeeee (ee 8888°M/8Meee) ee eeee 88 ee e eeeeeeeee eee; eeeee: 8.8e (88%).

References


Cookie-Einstellungen