N-Aminopyridinium Reagents as Traceless Activating Groups in the Synthesis of N-Aryl Aziridines
David Powers describes the use of N-aminopyridinium reagents in olefin aziridination reactions.
Nitrene transfer catalysis has been broadly investigated, because it provides the opportunity to efficiently install nitro-gen-containing functional groups via C–H amination or olefin aziridination. Professor David Powers’ group at Texas A&M University (USA) became involved in this area of science while studying the inorganic chemistry of metal nitrenes. Over the past 5 years, they have been developing new tools to study the chemical structures of transient nitrenes by in crystallo photochemistry. During these studies the group realized that while enormous progress has been made in nitrene transfer chemistry, significant limitations plagued most modern methods.
The Powers group envisioned that N-aminopyridinium salts could expand the utility of formal nitrene transfer chemistry because these reagents are inherently bifunctional. Professor Powers explained that “the N-amino group can engage as a nucleophilic moiety in an amination reaction and the N–N bond in the resulting aminopyridinium compound could be engaged as an electrophilic moiety.”