Access to beta-Lactams by Enantioselective Palladium(0)-Catalyzed C(sp(3))-H Alkylation
beta-Lactams are very important structural motifs because of their broad biological activities as well as their propensity to engage in ring-opening reactions. Transitionmetal- catalyzed C-H functionalizations have emerged as strategy enabling yet uncommon highly efficient disconnections. In contrast to the significant progress of Pd-0-catalyzed C-H functionalization for aryl-aryl couplings, related reactions involving the formation of saturated C(sp(3))-C(sp(3)) bonds are elusive. Reported here is an asymmetric C-H functionalization approach to beta-lactams using readily accessible chloroacetamide substrates. Important aspects of this transformation are challenging C(sp(3))-C(sp(3)) and strain-building reductive eliminations to for the four-membered ring. In general, the blactams are formed in excellent yields and enantioselectivities using a bulky taddol phosphoramidite ligand in combination with adamantyl carboxylic acid as cocatalyst.