Asymmetric catalysis on sequentially-linked columns.

We report a catalytic asymmetric reaction process that involves the use of solid-phase reagents and catalysts that constitute the packing of a series of "reaction columns". This process was applied to the catalytic asymmetric synthesis of beta-lactams, to yield pure products with excellent enantio- and diastereoselectivity. We have identified several advantages to conducting chemical reactions on sequential columns, including ease of catalyst and reagent recovery and simplified purification steps that preclude the need for chromatography.