Evidence against the reactive rotamer explanation of the gem-dialkyl effect
Acceleration of intramolecular reaction rates with increasing substitution has been known for a long time. The most common explanation used for this phenomenon is the 'Reactive Rotamer Effect' which states that "The ring closure reaction proceeds at a greater rate on geminal (or alkyl) substitution because of the resultant decrease in unprofitable rotamer distribution".1 This research presents evidence against this explanation and suggests an alternate explanation for the cause of the gem-dialkyl effect. © 1994.
Parrill, A., & Dolata, D. (1994). Evidence against the reactive rotamer explanation of the gem-dialkyl effect. Tetrahedron Letters, 35 (40), 7319-7322. https://doi.org/10.1016/0040-4039(94)85303-7