Fluorocyclisation via I(I)/I(III) catalysis: a concise route to fluorinated oxazolines.

ABSTRACT: Herein, we describe a catalytic fluorooxygenation of readily accessible N-allylcarboxamides via an I(I)/I(III) manifold to generate 2-oxazolines containing a fluoromethyl group. Catalysis is conditional on the oxidation competence of Selectfluor^®, whilst HF serves as both a fluoride source and Brønsted acid activator. The C(sp³)-F bond of the mono-fluoromethyl unit and the C(sp³)-O bond of the ring are aligned in a synclinal relationship thereby engaging in stabilising hyperconjugative interactions with vicinal, electron-rich ?-bonds (?_C-C??*_C-F and ?_C-H??*_C-O). This manifestation of the stereoelectronic gauche effect was established by X-ray crystallographic analysis of a representative example. Given the importance of fluorine in drug discovery, its ability to modulate conformation, and the prevalence of the 2-oxazoline scaffold in Nature, this strategy provides a rapid entry into an important bioisostere class.

SUBMITTER: Scheidt F 

PROVIDER: S-EPMC6009682 | biostudies-literature | 2018

REPOSITORIES: biostudies-literature