Functionalizations of Mixtures of Regioisomeric Aryllithium Compounds by Selective Trapping with Dichlorozirconocene
作者:Alicia Castelló-Micó、Simon A. Herbert、Thierry León、Thomas Bein、Paul Knochel
DOI:10.1002/anie.201508719
日期:2016.1.4
The reaction of mixtures of aryllithium regioisomers obtained either by directed lithiation or by Br/Li exchange with substoichiometric amounts of Cp2ZrCl2 proceeds with high regioselectivity. The least sterically hindered regioisomeric aryllithium is selectively transmetalated to the corresponding arylzirconium species leaving the more hindered aryllithium ready for various reactions with electrophiles
A novel Brønsted acid catalyst for Friedel–Crafts acylation
作者:Anna G. Posternak、Romute Yu. Garlyauskayte、Lev M. Yagupolskii
DOI:10.1016/j.tetlet.2008.11.038
日期:2009.1
Bis(trifluoroalkylsulfonylimino)trifluoromethanesulfonic acid has demonstrated remarkable catalytic ability in the electrophilic acylation of aromatic substrates. Various perfluoroalkyl substituted aroyl chlorides are employed in Friedel–Crafts acylation typically using 1 mol % of catalyst.