Open Access. Powered by Scholars. Published by Universities.®

Chemistry Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 2 of 2

Full-Text Articles in Chemistry

Probing The Mechanisms Of Enantioselective Hydrogenation Of Simple Olefins With Chiral Rhodium Catalysts In The Presence Of Anions, Jillian M. Buriak, Jason C. Klein, Deborah Herrington, John A. Osborn Dec 1999

Probing The Mechanisms Of Enantioselective Hydrogenation Of Simple Olefins With Chiral Rhodium Catalysts In The Presence Of Anions, Jillian M. Buriak, Jason C. Klein, Deborah Herrington, John A. Osborn

Peer Reviewed Articles

The strong influence of various anions upon the hydrogenation of 2-phenyl-1-butene, catalyzed by chiral rhodium catalysts was investigated. Both sulfonates and halides exert large increases in the enantioselectivity when [Rh{(−)-bdpp}(NBD)]ClO4 (bdpp=2,4-bis(diphenylphosphino)pentane, NBD=2,5-norbornadiene) is used as the catalyst precursor at high pressures (70 atm) of dihydrogen in nonpolar solvents. A dihydride mechanism similar to that for Wilkinson's catalyst [RhCl(PPh3)3] was shown to be operating at both high- and low-pressure conditions through a combination of catalytic studies, 31P, 1H and parahydrogen-induced polarization (PHIP) NMR experiments. With sulfonate and in neat methanol, however, a mechanistic switch takes place from a dihydride route (dihydrogen …


Chemistry Reform Takes Root In University Settingeforms In Mathematics And Science, Thomas Pentecost Jan 1999

Chemistry Reform Takes Root In University Settingeforms In Mathematics And Science, Thomas Pentecost

Peer Reviewed Articles

Which of the following scenarios is more attractive?

(1) You arrive for chemistry class and listen and watch an

instructor work problems about gas laws for fifty minutes.

(2) You arrive for class and you and a few other classmates anake

data about the relationship between pressure and volume and develop

the gas laws based on data.