Arylboration of Enecarbamates for the Synthesis of Borylated Saturated N-Heterocycles

Two catalytic systems have been developed for the arylboration of endocyclic enecarbamates to deliver synthetically versatile borylated saturated N-heterocycles in good regio- and diastereoselectivities. A Cu/Pd dual catalytic reaction enables the synthesis of borylated, alpha-arylated azetidines, while a Ni-catalysed arylboration reaction efficiently functionalizes 5-, 6-, and 7-membered enecarbamates. In the case of the Cu/Pd-system, a remarkable additive effect was identified that allowed for broader scope. The products are synthetically useful, as demonstrated by manipulations of the boronic ester to access biologically active compounds.

Automated summary

Two catalytic systems have been developed for the arylboration of endocyclic enecarbamates, resulting in the synthesis of versatile borylated saturated N-heterocycles with good regio- and diastereoselectivities. The Cu/Pd dual catalytic reaction enables the synthesis of borylated, alpha-arylated azetidines, while the Ni-catalysed arylboration reaction efficiently functionalizes 5-, 6-, and 7-membered enecarbamates. The use of additives in the Cu/Pd system allows for a broader scope of reactions, and the products can be further manipulated to access biologically active compounds.