Facile synthesis of highly functionalized stable ketenimines by a three-component reaction of alkyl isocyanides, dialkyl acetylenedicarboxylates and ethyl carbazones
AbstractThe reactive intermediate generated by the reaction of alkyl isocyanides and dialkylacetylenedicarboxylates was trapped by ethyl carbazones to produce stable ketenimine derivatives in good yield. The reaction is characterized by mild conditions, high selectivity, and tolerance to various functional groups. Graphical abstract
A gold(I) autotandem catalysis protocol is reported for the de novo synthesis of densely substituted pyrazolines and dihydropyridines from the corresponding imine derivatives in a highly regioselective fashion via a one-pot aza-enyne metathesis/6π-electrocyclization sequence. The substituents on the nitrogen atom of the imine perfectly control the reaction pathways from the pivotal 1-azabutadiene intermediate;