Stereoselective Synthesis of Diazabicyclic β‑Lactams through Intramolecular Amination of Unactivated C(sp3)–H Bonds of Carboxamides by Palladium Catalysis

An efficient C­(sp3)–H bond activation and intramolecular amination reaction via palladium catalysis at the β-position of carboxyamides to make β-lactams was described. The investigation of the substrate scope showed that the current reaction conditions favored activation of the β-methylene group. Short sequences were developed for preparation of various diazabicyclic β-lactam compounds with this method as the key step from chiral proline and piperidine derivatives.