December 15, 2008

Hydrocarbons activate! Graduate student Yosra Badiei’s research in Prof. Timothy Warren’s laboratory has been recognized by the editors of Angewandte Chemie International Edition in a “Hot Paper” (“Copper-Nitrene Complexes in C-H Amination” Angew. Chem. Int. Ed. 2008, 47, 9961-9964). Yosra’s work connects highly reactive copper complexes to a catalytic reaction which directly converts normally unreactive C-H bonds to C-N bonds. Numerous natural and pharmaceutical small molecule targets as well as technologically important materials contain C-N bonds, prompting cost-effective and environmentally benign approaches for their synthesis. C-H amination is an emerging green technology to introduce nitrogen groups into an organic molecule without the need for a pre-functionalized site, offering the opportunity to streamline chemical syntheses with reduced cost, energy consumption, and environmental impact.

The combination of an organoazide with a copper complex leads to highly reactive copper-nitrene intermediates with properties that neither alone possesses– reactivity with hydrocarbons under mild conditions. Despite its extreme reactivity, Yosra fully characterized the catalytic intermediate 1, including its X-ray structure which shows a triangular arrangement of two copper centers bridged by the reactive nitrogen atom.

Co-author NSF-REU student Robert Palomino (summer 2006) first prepared a related copper complex which allowed this reactivity to be discovered. Computational collaborators Prof. Tom Cundari and student Adriana Dinescu at the University of North Texas also contributed with a theoretical understanding of these highly reactive species. This work was supported by the National Science Foundation as well as the Alexander von Humboldt Foundation. Graduate student Yosra Badiei is a recipient of a Doctoral Dissertation Research Fellowship from the Graduate School.