Synthesis of C2 Symmetric 2,2’-Bipyridyl Imidazolidinone and Oxazaborolidine Derivatives

4,4′-Bis(bromomethyl)-2,2′-bipyridine reacts with (4R,5R)-1propanoyl-4,5-diphenylimidazolidinone to form a C 2 symmetric chiral bipyridine derivative.Similarly reaction of 4,4′-bis(bromomethyl)-2,2′-bipyridine with an amino alcohol prepared from L-tyrosine affords a C 2 symmetric diaminodiol.Treatment of the latter product with either borane or trimethylboroxine forms oxazaborolidines that have been used as catalysts in the asymmetric reduction of acetophenone.High enantiomeric excesses are obtained.