Advertisement

If you have an ACS member number, please enter it here so we can link this account to your membership. (optional)

ACS values your privacy. By submitting your information, you are gaining access to C&EN and subscribing to our weekly newsletter. We use the information you provide to make your reading experience better, and we will never sell your data to third party members.

ENJOY UNLIMITED ACCES TO C&EN

Synthesis

Selectively Axing Halogens With Light

Chemists harness the energy from a simple fluorescent light to selectively dehalogenate complex substrates

by Carmen Drahl
June 22, 2009 | A version of this story appeared in Volume 87, Issue 25

If you're having trouble removing a halogen atom from a highly functionalized intermediate, a trip to Home Depot might be in order. Jagan M. R. Narayanam, Joseph W. Tucker, and Corey R. J. Stephenson of Boston University have harnessed the energy from a store-bought 14-W fluorescent bulb to selectively remove halogens from complex substrates without disturbing sensitive functional groups such as hydroxyls, olefins, and alkynes (J. Am. Chem. Soc., DOI: 10.1021/ja9033582). Established dehalogenation reactions tend to have poor selectivity, rely on toxic tin reagents, or both. The new method employs a common ruthenium catalyst, Ru(bipyridyl)32+, to capture visible light energy from a lamp and introduce electrons into dehalogenations, such as the one shown. So far, the reaction requires a nearby functional group to activate the halogen, but the team hopes to tackle nonactivated halogens by tweaking the catalyst. Beyond dehalogenations, "one could easily imagine that this strategy could be used as a general method to initiate radical reactions," notes Tehshik P. Yoon of the University of Wisconsin, Madison, who has used a similar system for cycloaddition reactions.

Article:

This article has been sent to the following recipient:

0 /1 FREE ARTICLES LEFT THIS MONTH Remaining
Chemistry matters. Join us to get the news you need.