Metal-free catalyst shielding studied

U.S. scientists say they've found a simple metal free catalyst that can shield a specific alcohol without modifying another nearby alcohol.

Amir Hoveyda and colleagues at Boston College and Scott Denmark and colleagues at the University of Illinois-Urbana say protecting groups are often needed in organic synthesis to shield one part of a molecule from chemical change while another part of the same molecule is altered.

The catalyst found by the researchers puts a protecting group called a silyl ether onto a class of compounds called secondary alcohols, and by protecting that specific alcohol, a chemist can now selectively modify the remaining "unprotected" alcohol.

Since the catalyst does not contain any metals it is more environmentally friendly -- or "greener" -- than many other catalysts, the researchers said. And it can easily be prepared from commercially available materials.

The research is explained in the current issue of the journal Nature.

Copyright 2006 by United Press International