Trifluoromethyl-substituted phenylsilanes: the regiochemical course of their metalation dictated by buttressing effects

Triethyl[(2-trifluoromethyl)phenyl]silane reacts with the superbasic LIC-KOR mixt. of butyllithium and potassium tert-butoxide exclusively at the 4-position ("meta-metalation") and not at all at the 3-position ("ortho-metalation"). Two further substrates which simultaneously contain two trifluoromethyl groups, triethyl[2,4- and 2,5-bis(trifluoromethyl)phenyl]silane, undergo deprotonation at the 5- and 4-position, resp. Thus, a buttressing effect blocks the attack of metalating agents on the ortho position of any trifluoromethyl group which is neighbored, on the other side, by a trialkyl substituent. [on SciFinder (R)]


Published in:
European Journal of Organic Chemistry, 3, 735-737
Year:
2006
Note:
29 Organometallic and Organometalloidal Compounds Institute of Chemical Sciences and Engineering,Ecole Polytechnique Federale,Lausanne,Switz. Journal 1434-193X written in English.
Laboratories:




 Record created 2006-03-03, last modified 2018-01-27


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