ortho-Arylation of ortho-substituted benzoic acids is a challenging process due to the tendency of the reaction products toward Pd-catalyzed protodecarboxylation. A simple method for preventing decarboxylation in sterically hindered benzoic acids is reported. The method described represents a reliable and broadly applicable entry to 2-aryl-6-substituted benzoic acids.
Carboxylic Acids as Traceless Directing Groups for Formal meta-Selective Direct Arylation
作者:Josep Cornella、Marika Righi、Igor Larrosa
DOI:10.1002/anie.201103720
日期:2011.9.26
Without a trace: The first meta‐selective direct CH arylation that uses iodoarenes as coupling partners is reported (see scheme, EWG=electron‐withdrawing group). This process utilizes carboxylicacid units as temporary directinggroups that are cleaved during the reaction, leaving no trace in the resulting biaryl products.