Utility of the Nudged Elastic Band Method in Identifying the Minimum Energy Path of an Elementary Organometallic Reaction Step

The nudged elastic band (NEB) method has been used to re-examine the oxidative addition step in the classic rhodium-catalyzed hydroacylation reaction. Numerous additional intermediates were found on a pathway that is lower in energy than that originally reported. This study illustrates the potential limitations of the traditional approach to locating transition states in which a chemical-intuition-guided linear or quadratic synchronous transit is used to estimate the high point of the reaction trajectory. Utilization of that approach constrains the search so that the actual transition state and other possible intermediates and transition states may be missed.