Divergent Catalysis: Catalytic Asymmetric [4+2] Cycloaddition of Palladium Enolates

An
asymmetric decarboxylative [4+2] cycloaddition from a catalytically
generated chiral Pd enolate was developed, forging four contiguous
stereocenters in a single transformation. This was achieved through
a strategy termed divergent catalysis, wherein departure from a known
catalytic cycle enables novel reactivity of a targeted intermediate
prior to re-entry into the original cycle. Mechanistic studies including
quantum mechanics calculations, Eyring analysis, and KIE studies offer
insight into the reaction mechanism.