A novel type of phosphoric acid catalyst with enhanced reactivity is reported. These compounds possess one or two positively charged centers which electrostatically activate them. This is illustrated in several bond-forming transformations including Friedel-Crafts and Diels-Alder reactions as well as a ring-opening polymerization. Rate accelerations corresponding to orders of magnitude are observed.
Bibliographical noteFunding Information:
We thank Ms. Deborah K. Schneiderman (University of Minnesota) for helpful discussions. Generous support from the National Science Foundation (CHE-1361766) and the Petroleum Research Fund (556313-ND4) as administered by the American Chemical Society is also gratefully acknowledged.
© 2016 American Chemical Society.