802984-54-9Relevant articles and documents
Buttressing effects on haloarene deprotonation: A merely kinetic or also thermodynamic phenomenon?
Gorecka, Joanna,Heiss, Christophe,Scopelliti, Rosario,Schlosser, Manfred
, p. 4591 - 4593 (2004)
(Chemical equation presented) (2,6-Dichlorophenyl)- and (2,6-dibromophenyl)trialkylsilanes undergo hydrogen/metal interconversion preferentially at the 4- rather than 3-position. However, the organometallic species generated by such a meta metalation are thermodynamically less stable (i.e., more basic) than those that would result from an ordinary ortho metalation . This was demonstrated by equilibration experiments based on permutational halogen/ metal interconversion. A new buttressing effect can explain the unprecedented regioselectivity. It is supported by X-ray structures that reveal marked deformations of the benzene ring in halophenylsilanes.
