Syntheses of imidazo-, oxa-, and thiazepine ring systems via ring-opening of aziridines/Cu-catalyzed C-N/C-C bond formation.

Manas K Ghorai, Ashis Kumar Sahoo, Aditya Bhattacharyya

Index: J. Org. Chem. 79(14) , 6468-79, (2014)

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Abstract

A simple and unpredicted synthetic pathway toward racemic and scalemic tetrahydrodibenzoimidazoazepines has been invented serendipitously proceeding through an S(N)2-type ring-opening of N-activated aziridines with 2-bromobenzylamine followed by a hitherto unprecedented cascade cyclization reaction sequence comprising a Cu-catalyzed cross dehydrogenation C-N coupling and an Ullmann C-C bond formation reaction. The tetrahydrobenzoxazepine and the tetrahydrobenzothiazepine derivatives have also been synthesized via the ring-opening of aziridines with 2-bromobenzyl alcohols and -mercaptan, respectively, followed by Cu-catalyzed N-arylation reaction.