Stereodivergent Allylation of Azaaryl Acetamides and Acetates by Synergistic Iridium and Copper Catalysis

Enantioselective Reaction between 2-(Cyanomethyl)azaarenes and N-Boc-amino Sulfones

A series of 2-(cyanomethyl)azaarenes containing benzothiazole or benzoxazole were designed and synthesized for asymmetric α-functionalization with N-Boc-amino sulfones. The Mannich adducts were obtained in high yields with good diastereo- and enantioselectivities. Aryl-substituted amino sulfones were tolerated under the current conditions, and the reaction can be performed on gram scale in good results.

C-N Bond Formation from Allylic Alcohols via Cooperative Nickel and Titanium Catalysis

Amination of allylic alcohols is facilitated via cooperative catalysis. Catalytic Ti(O- i-Pr)₄ is shown to dramatically increase the rate of nickel-catalyzed allylic amination, and mechanistic experiments confirm activation of the allylic alcohol by titanium. Aminations of primary and secondary allylic alcohols are demonstrated with a variety of amine nucleophiles. Diene-containing substrates also cyclize onto the nickel allyl intermediate prior to amination, generating carbocyclic amine products. This tandem process is only achieved under our cooperative catalytic system.

Iridium-catalyzed enantioselective direct vinylogous allylic alkylation of coumarins

The first iridium-catalyzed enantioselective vinylogous allylic alkylation of coumarins is presented. Using easily accessible linear allylic carbonates as the allylic electrophile, this reaction installs unfunctionalized allyl groups at the γ-position of 4-methylcoumarins in an exclusively branched-selective manner generally in high yields with an excellent level of enantioselectivity (up to 99 : 1 er).