title: DFT-based mechanistic insights into noble metal-catalyzed rearrangement of propargylic derivatives: chirality transfer processes.
abstract: Cascade transformations of enynes and propargylic acyl derivatives triggered by the π-acid activation of the alkyne by gold or platinum catalysts can afford diverse and complex molecular skeletons under mild conditions in an atom-economical manner. Often the rearrangements benefit from additional roles of the metal, either activating other functional groups and/or organizing the intermediates for further reactions. Mechanistic insights gleaned from kinetic and labeling studies have been complemented by quantum chemical calculations for different substrates and reaction types, which show some common features that can be traced back to the combination of the propargylic system and the noble metal catalyst. Among other results, theoretical studies of the reactivity of some systems revealed the prevalence of very low barriers for the bond-forming/bond-breaking processes along complex multistep mechanistic manifolds. As a consequence, the barriers corresponding to conformational changes (single bond rotations, helix inversions…) of the intermediates acquire unexpected importance. Thus, memory of chirality in reactions of enantiopure substrates is preserved, in some cases, in formally planar intermediates that however do not undergo conformational scrambling. In this chapter we will review how computational chemistry continues to play a key role in our understanding and interpretation of the catalytic cycles of complex transformations catalyzed by gold and platinum, in particular those involving transfer of chirality.
authors.affiliation: Departamento de Química Orgánica, Universidade de Vigo, As Lagoas/Marcosende, Spain. faza@uvigo.es
authors.forename: Olalla Nieto
authors.initials: ON
authors.lastname: Faza
authors.forename: Angel R
authors.initials: AR
authors.lastname: de Lera