Nitrile imines in a flash

摘要

Nitrile imines, R-CNN-R', are common intermediates in organic synthesis, including 'click' chemistry. A team led by Professor Curt Wentrup at the University of Queensland has shown that the two potential forms of nitrile imines, propargylic and allenic, can be generated selectively by matrix photolysis, and in some cases also flash vacuum thermolysis, of tetrazole precursors. The two forms can be clearly differentiated by matrix-isolation IR spectroscopy in conjunction with anharmonic frequency calculations. Thus, IR spectroscopy is found to be a reliable tool for the determination of structures of nitrile imines, the propargylic forms absorbing above 2200 cm~(-1), and the allenic ones in the 2000-2100 cm~(-1) range (Begue D., Qiao G.G., Wentrup C. J. Am. Chem. Soc. 2012, 134, 5339-50).