Discovery of Novel Catalysts for Allylic Alkylation with a Visual Colorimetric Assay.

The first non-phosphane iridium catalyst, made from [{IrCl(cod)}(2)] and iPr-pybox (shown schematically; cod=1,5-cyclooctadiene), for allylic alkylation in neutral medium was discovered by a simple, rapid, and inexpensive screening assay. The red coloration upon treatment of the reaction mixtures with Fast Red (see the 96-well plate) indicates the presence of 1-naphthol and thus the occurrence of allylic alkylation.