RESUMO
A straightforward and selective way for the preparation of amides from nitroarenes and carboxylic acids using carbon monoxide as a reductant was developed. This protocol does not require any non-gaseous additives, thus simplifying product isolation. Aliphatic carboxylic acid was modified in the presence of aromatic ones, and reducible functional groups such as CîC, Ar-Br, and R-NO2 were saved.
RESUMO
Nowadays, design of the new chiral ligands for organometallic catalysts is often based on the step-by-step increase in their complexity to improve efficiency. Herein we describe that simple in situ addition of the fluoride source to the asymmetric organometallic catalyst can improve not only activity but also enantioselectivity. Bromide-nickel diimine complexes were found to catalyze asymmetric Michael addition in low yields and ee, but activation with fluoride leads to a significant improvement in catalyst performance. The developed approach was applied to prepare several enantioenriched GABA analogues.