Novel Cobalt-catalyzed [2+2] Reaction (IMAGE) Princeton University Caption Researchers at Princeton have developed a cobalt-catalyzed [2π+2π] reaction that may give unprecedented access to cyclobutanes, four-membered ring-containing molecules. Credit Image courtesy of the Chirik lab Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.