Asymmetric Synthesis of β-Lactams Through the Staudinger Reaction and Their Use as Building Blocks of Natural and Nonnatural Products

In the last two decades, the better understanding of the mechanistic aspects of the β-lactams' biological activity and their inhibition, and the chemical exploitation of β-lactams as synthetic intermediates in organic chemistry, have experienced a continuous and somewhat complementary advance. A prerequisite for such a development has been the accessibility of enantiopure β-lactams. The latter are now routinely prepared most often through the ketene-imine cycloaddition reaction, also termed the Staudinger reaction. This review accounts for the recent progress made in the asymmetric synthesis of β-lactams (with special emphasis in the Staudinger reaction approach), as well as in their use as synthetic intermediates en route to natural products, including α- and β-amino acids and peptides derived therefrom.