Direct organocatalytic synthesis of enantiopure succinimides from β-lactam aldehydes through ring expansion promoted by azolium salt precatalysts

摘要

A single-step catalytic ring expansion approach from 4-oxoa-zetidine-2-carbaldehydes to enantiopure succinimides has been achieved by the use of a base (DBU) and a thiazolium salt precatalyst. Succinimides constitute an important compound class due to their wide profile of biological activity. Besides, the succinimide nucleus is a useful building block for the synthesis of natural as well as unnatural products, and succinimide-based pseudopeptides have been shown to stabilize P-tura conformations.