Avoiding Undesired\nIntramolecular Diketopiperazine\nFormation during Peptoid Chain Elongation Using a Microflow Reactor

Avoiding\nundesired intramolecular reactions during desired\nintermolecular\nreactions is an important challenge in synthetic organic chemistry.\nWe successfully avoided undesired intramolecular diketopiperazine\nformation during desired N-alkylation in the synthesis of peptoids\nusing a microflow reactor. Fifteen peptoids were synthesized in good\nto high yields, and a cyclic peptoid was synthesized on the gram scale\nusing the developed microflow approach. The productivity and cost\nof our approach are significantly superior to those of the conventional\nsolid-phase approach.