Copper(I)‐Catalyzed Asymmetric Vinylogous Aldol‐Type Reaction of Allylazaarenes

A vinylogous aldol‐type reaction of allylazaarenes and aldehydes is disclosed that affords a series of chiral γ‐hydroxyl‐α,β‐unsaturated azaarenes in moderate to excellent yields with high to excellent regio‐ and enantioselectivities. With ( R , R P )‐TANIAPHOS and ( R , R )‐QUINOXP* as the ligand, the carbon‐carbon double bond in the products is generated in ( E )‐form. With ( R )‐DTBM‐SEGPHOS as the ligand, ( Z )‐form carbon‐carbon double bond is formed in the major product. In this vinylogous reaction, aromatic, α,β‐unsaturated, and aliphatic aldehydes are competent substrates. Moreover, a variety of azaarenes, such as pyrimidine, pyridine, pyrazine, quinoline, quinoxaline, quinazoline, and benzo[d]imidazole are well‐tolerated. At last, the chiral vinylogous product is demonstrated as a suitable Michael acceptor towards CuI‐catalyzed nucleophilic addition with organomagnesium reagents.