183. Stereoselective and Enantiospecific Mono- and Bis-C−H azidation of Tröger Bases. Insight on Bridgehead Iminium Intermediates and Application to Anion-Binding Catalysis
     Alessandro Bosmani, Sandip Pujari, Laure Guenée, Céline Besnard, Amalia Isabel Poblador Bahamonde, Jérôme Lacour
     Chem. Eur. J. 2017, 23, 8678-8684

In the context to Tröger base chemistry, regio and stereoselective C_sp3-H azidation reactions are reported. Azide functional groups are introduced at either one or the two benzylic positions selectively. Mild conditions and good yields are afforded by the combination of TMSN₃ and iodosobenzene PhIO. The process occurs with high enantiospecificity (es 96-99%) and, interestingly and importantly, via bridgehead iminium intermediates as shown by mechanistic and in-silico studies. Finally, mono and bis triazole derivatives were prepared in high yields and enantiospecificity using CuAAC reactions; some of the products being used as anion-binding organocatalysts for the tritylation of amines and alcohols.

DOI : 10.1002/chem.201700845 

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