β‐Lactam Synthesis through Diodomethane Addition to Amide Dianions

Abstract

We present a novel route for the quick and easy synthesis of a broad range of β‐lactams. The synthesis involves a [3+1] cyclization of amide dianions with diiodomethane. In contrast to the seminal work of Hirai et al. from 1979, the reaction proved to be a general and efficient approach towards azetidinones. The ease of the process was confirmed by DFT calculations and its power demonstrated by a diversity‐oriented synthesis of β‐lactams with four points of diversity determined by the choice of Ugi adducts as starting materials.

A Mn(OAc)3-Triggered Formation of Cyclopropanes from Ugi Adducts

“…Finally, Ugi adduct 1i was prepared using the N - tert -butyl mono amide of malonic acid as starting acidic partner instead of the previous malonic ester. 8 The oxidation of amide 1i led to the expected cyclopropane 2i obtained in a low 37% isolated yield, a result that could be explained by a higher steric hindrance of the amide compared to the previous esters.…”