Better protection.A new molecular catalyst shortens a widely used reaction into a one-step process, with a bonus: It makes the reaction's products into one of two possible mirror-image forms. When chemists synthesize To create a whole or complete unit from parts or components. See synthesis. compounds, they often add a protective group of atoms to a specific site on a molecule to prevent that site from reacting in subsequent steps. For example, a silicon-based group is added to an alcohol site in many syntheses of organic molecules, says Marc L. Snapper snapper, name for members of the Lutianidae, a family of spiny-finned food and game fishes found chiefly in tropical coastal waters. Snappers are carnivorous, active, and voracious, with large mouths and sharp teeth. Most species travel in dense schools. of Boston College Boston College, main campus at Chestnut Hill, Mass.; coeducational; Jesuit; est. and opened 1863. Actually a university, the school's Chestnut Hill campus comprises colleges of arts and sciences and business administration, the graduate school, and schools of nursing . However, protecting an alcohol site in this manner previously required up to seven chemical steps, he notes. To expedite the process, Snapper, Amir H. Hoveyda For the former Iranian prime minister, see Amir-Abbas Hoveida. Amir H. Hoveyda is professor of chemistry at Boston College at the US, and currently holds the position of department chair. , and their Boston College coworkers searched for a small molecule that could catalyze that addition in a single step. Furthermore, chemists often want to synthesize one of two possible mirror-image forms, or chiral chi·ral adj. Of or relating to the structural characteristic of a molecule that makes it impossible to superimpose it on its mirror image. chi·ral molecules. The function of some molecules depends on its mirror-image form. Snapper and his colleagues used their catalyst, which is chiral, on a compound with two alcohol groups in symmetrical positions on the molecule. The catalyst added the protecting group A Protecting group or protective group is introduced into a molecule by chemical modification of a functional group in order to obtain chemoselectivity in a subsequent chemical reaction. It plays an important role in multistep organic synthesis. to only one position, making the compound also chiral. The researchers report in the Sept. 7 Nature that the reaction makes 98 percent of one mirror-image form and only 2 percent of the other. The researchers are now working to improve the speed of the reaction and apply the catalyst to compounds with different numbers of alcohol groups. |
|
||||||||||||||||||||||
Printer friendly
Cite/link
Email
Feedback
Reader Opinion