David S. Glueck, Department of Chemistry, Dartmouth College, is supported by the Inorganic, Bioinorganic and Organometallic Chemistry Program for his work on stereoselective P-C bond formation. Glueck has recently shown that a chiral Pd(0) complex catalyzes the asymmetric coupling of a secondary phosphine (RR'PH) with an aryl halide (ArX) to give a chiral tertiary phosphine (RR'ArP*). The mechanism of this reaction and the factors leading to the high stereoselectivity will be explored. One key factor to be studied is the relative rate of phosphorus inversion and reductive elimination in Pd phosphido complexes. The stereochemistry and diastereoselectivity of transmetalation and of reductive elimination will also be examined.
Chiral phosphines are frequently used in asymmetric catalytic transformations such as hydrogenation. The new "chiral at phosphorus" ligands prepared by Glueck are a complement to the better-known "backbone chirality" phosphines where a chiral alkyl group is attached to the phosphorus. In addition to these potential industrial applications, students working on this project will develop a broad set of skills in synthesis, characterization and catalysis.
