Professor Ken Houk’s group joins with the Scott Denmark group at University of Illinois Urbana-Champaign to explain the autocatalytic Soai reaction.
The Soai reaction shown below was discovered in the 1990s and has been studied by many groups since then. It is the paradigm of an asymmetric autocatalytic reaction; a tiny amount of chiral catalyst leads to a highly stereoselective formation of the corresponding nearly optically pure product. A new paper in Nature Chemistry gives the first comprehensive explanation of how this reaction works.
Professor Scott Denmark (shown below right) and his former graduate student, Dr. Soumitra V. Athavale (now with Frances Arnold at Caltech) performed exhaustive experimental studies on a modification of the reaction, shown below.
Kinetic studies with a surrogate substrate and spectroscopic analysis of a series of zinc alkoxides that incorporate specific structural mutations reveal that a tetrameric cluster functions as a catalyst that activates the substrate.
Transition-state modeling carried out by graduate student Adam Simon (shown below left) in the Houk group with density functional theory calculations gave details about how this stereoselectivity arises. Moreover, experimental and computational analysis of the heterochiral complex provides a definitive explanation for the nonlinear behaviour of this system. This investigation of the Soai system revealed the structural logic for autocatalyst evolution, function and substrate compatibility—a central mechanistic aspect of this iconic transformation.
To learn about the Houk group’s research, visit their website.