Note to users. If you're seeing this message, it means that your browser cannot find this page's style/presentation instructions -- or possibly that you are using a browser that does not support current Web standards. Find out more about why this message is appearing, and what you can do to make your experience of our site the best it can be.

Site Tools

  • AAAS
  • Subscribe
  • Feedback

Site Search

Search Advanced

Science 20 April 2007:
Vol. 316. no. 5823, pp. 439 - 441
DOI: 10.1126/science.1141474

Reports

Facile Splitting of Hydrogen and Ammonia by Nucleophilic Activation at a Single Carbon Center

Guido D. Frey, Vincent Lavallo, Bruno Donnadieu, Wolfgang W. Schoeller,* Guy Bertrand*

In possessing a lone pair of electrons and an accessible vacant orbital, singlet carbenes resemble transition metal centers and thus could potentially mimic their chemical behavior. Although singlet di(amino)carbenes are inert toward dihydrogen, it is shown that more nucleophilic and electrophilic (alkyl)(amino)carbenes can activate H2 under mild conditions, a reaction that has long been known for transition metals. However, in contrast to transition metals that act as electrophiles toward dihydrogen, these carbenes primarily behave as nucleophiles, creating a hydride-like hydrogen, which then attacks the positively polarized carbon center. This nucleophilic behavior allows these carbenes to activate NH3 as well, a difficult task for transition metals because of the formation of Lewis acid-base adducts.

UCR-CNRS Joint Research Chemistry Laboratory (UMI 2957), Department of Chemistry, University of California, Riverside, CA 92521–0403, USA.

* To whom correspondence should be addressed. E-mail: gbertran{at}mail.ucr.edu

Read the Full Text


THIS ARTICLE HAS BEEN CITED BY OTHER ARTICLES:
From the Cover: Allene formation by gold catalyzed cross-coupling of masked carbenes and vinylidenes.
V. Lavallo, G. D. Frey, S. Kousar, B. Donnadieu, and G. Bertrand (2007)
PNAS 104, 13569-13573
   Abstract »    Full Text »    PDF »



To Advertise     Find Products


Science. ISSN 0036-8075 (print), 1095-9203 (online)