Pentapeptide Nanoreactor as a Platform for Halogenations, Diels–Alder Reaction, and Morita–Baylis–Hillman Reaction

A pentapeptide nanoreactor has been designed and synthesized as a platform to carry out the traditional organic reactions such as bromination, iodination, cycloaddition, and condensation reactions. The pentapeptide Boc–Phe–Phe–Aib–Phe–Phe–OMe with a supramolecular helical structure and π-rich channel provides nanoconfinements and thus facilitates the organic reactions. Bromination and iodination of aniline take place without any halogen carrier (Lewis acid) in the pentapeptide platform. Iodination produced p-iodoaniline only. The Diels–Alder reaction between furan and maleic anhydride increased 2-fold in the pentapeptide platform and the Morita–Baylis–Hillman reaction of benzaldehyde and ethyl acrylate in methanol enhanced 1.5-fold.