Synthesis of Various Saturated and Unsaturated N‐Heterocyclic Carbene Precursors by Triflic Anhydride Mediated Intramolecular Cyclization

Abstract

Closing the circle: A versatile and modular method yields various saturated and unsaturated N-heterocyclic carbene precursors from a Tf2O-mediated intramolecular cyclization reaction. A resultant sterically demanding oxazolium salt could be used not only as good intermediate for directly preparing N,N′-disubstituted imidazolium salts in one step, but also as a precursor of sterically demanding oxazol-2-ylidene. As a service to our authors and readers, this journal provides supporting information supplied by the authors. Such materials are peer reviewed and may be re-organized for online delivery, but are not copy-edited or typeset. Technical support issues arising from supporting information (other than missing files) should be addressed to the authors. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.