The use of immobilized crown ethers as in-situ N-protecting groups in organic synthesis and their application under continuous flow

We report herein the successful immobilization of an 18-crown-6 ether derivative onto a solid support and discuss its incorporation into a continuous flow reactor whereby the sequestration of a series of primary amine salts is demonstrated. In addition, the material is subsequently employed as a non-covalent N-protecting group, providing a facile route to the O-acylation and O-alkylation of several amine derivatives without the need for formal protecting group chemistry.