Nucleophilic catalyst does kinetic resolution

Abstract

Chemists at Massachusetts Institute of Technology have invented a highly stereoselective nucleophilic catalyst, the most selective known to date-other than an enzyme-for acylating racemic alcohols. The organometallic catalyst is stable to air and moisture, both as a solid and in solutions. And the catalyst can be quantitatively recovered [ J. Am. Chem. Soc. , 119,1492 (1997)]. Most good nucleophiles are planar amines like 4-dimethylaminopyridine, and it is hard to add asymmetry to such molecules to get good stereoselectivity. Graduate student J. Craig Ruble, postdoctoral fellow Hallie A. Latham, and organic chemistry professor Gregory C. Fu attacked the problem by cobbling a cyclopentadiene ring onto the 4-dimethylaminopyridine moiety and making it an integral part of a chiral ferrocene analog. The other portion of the ferrocene coordinated to the iron atom is pentaphenyl-cyclopentadiene. The MIT workers use this supracyclopentadiene, as some other researchers have dubbed it, to add steric bulk to the s...