An unexpected copper catalyzed 'reduction' of an arylazide to amine through the formation of a nitrene intermediate.

ABSTRACT: Azido nitrobenzoxadiazole (NBD) was observed to undergo a 'reduction' reaction in the absence of an obvious reducing agent, leading to amine formation. In the presence of an excess amount of DMSO, a sulfoxide conjugate was also formed. The ratio of these two products was both temperature- and solvent-dependent, with the addition of water significantly enhancing the ratio of the 'reduction' product. Two intermediates of the azido-NBD reaction in DMSO were trapped and characterized by low-temperature EPR spectroscopy. One was an organic free radical (S=1/2) and another was a triplet nitrene (S=1) species. A mechanism was proposed based on the characterized free radical and triplet intermediates.

SUBMITTER: Peng H 

PROVIDER: S-EPMC3752911 | biostudies-literature | 2013 Jun

REPOSITORIES: biostudies-literature