Entropy effects in temperature-regulated nickel-catalyzed regiodivergent alkene hydroalkylation

Abstract

Temperature-regulated nickel-catalyzed regiodivergent alkene hydroalkylation has been reported, yet there is a lack of a reasonable explanation for the regulation mechanism. Herein, we conduct a systematic analysis of the pertinent data, aiming to reveal the potential role and mechanism of temperature in regioselectivity. Alkyl radicals trapped by Ni(I) species are reasonably well-formed. Following this, entropic effects at different temperatures are found to be responsible for the regioselectivity turnover. Intramolecular transformation (β-H elimination) was less sensitive than the intermolecular step (radical addition and reductive elimination) for the entropy change; influencing the entropy response through temperature led to the regioselectivity regulation. These findings deepen our understanding of the influence of temperature on the regioselectivity of nickel-catalyzed alkene hydroalkylation.