High-pressure mechanistic delineation based on activation volumes

High‐pressure kinetics is a useful tool for the determination and the assessment of mechanisms in organic chemistry. The volume of activation ΔV* deduced from these kinetic measurements is an indicator of the position of the transition state. In addition, if accurately determined, ΔV* permits the detection of fine mechanistic effects such as alteration of mechanism according to substrates within the same reaction type, operation of secondary orbital interactions in Diels–Alder cycloadditions, angular hydrogen transfer in ene reactions, etc. Copyright © 2001 John Wiley & Sons, Ltd.