Copper-Catalyzed Hydroamination of Oxa- and Azabenzonorbornadienes with Pyrazoles

An efficient and highly chemo- and stereoselective copper-catalyzed hydroamination of oxa- and azabenzonorbornadienes with various pyrazole derivatives is described. This catalytic process is promoted by the presence of N-heterocyclic carbene ligands and KOt-Bu under mild and simple reaction conditions, and allows for the direct synthesis of new and versatile functionalized oxa(aza)benzonorbornyl pyrazoles starting from readily available oxa(aza)bicyclic alkenes. The synthetic utility of this method was demonstrated by the transformation of the obtained products into pyrazolyl-substituted naphthalenes.

Catalytic asymmetric transformations of oxa- and azabicyclic alkenes

This review provides an overview of the fundamental concepts and recent developments in a wide range of enantioselective transformations involving oxa- and azabicyclic alkenes.

Oxa- and Azabenzonorbornadienes as Electrophilic Partners under Photoredox/Nickel Dual Catalysis

Herein, the introduction of oxa- and azabenzonorbornadienes into photoredox/nickel dual catalysis in a regioselective and diastereoselective transformation is disclosed. The inherent advantages of this dual catalytic system allow the use of alkyl motifs forming exclusively cis-1,2-dihydro-1-naphthyl alcohol backbones using readily accessible 4-alkyl-1,4-dihydropyridines (DHPs). Whereas previous studies have emphasized the use of nucleophilic organometallic coupling partners, this protocol grants access to a rather unexplored core featuring alkyl residues, while avoiding the use of highly reactive organometallic species (i.e., M = Al, Mg, Li, Zn, Zr). DFT calculations support a oxidative addition/reductive elimination mechanism, followed by a Curtin-Hammett scenario that controls the regioselectivity of the process, unlike previously reported transformations that proceed via a carbometalation/ β-oxygen elimination mechanism.