Synthesis of C2 symmetric 2,2′-bipyridyl imidazolidinone and oxazaborolidine derivatives

Article abstract of DOI:10.3987/com-01-s(k)12

4,4′-Bis(bromomethyl)-2,2′-bipyridine reacts with (4R, 5R)-1-propanoyl-4,5-diphenylimidazolidinone to form a C₂ symmetric chiral bipyridine derivative. Similarly reaction of 4,4′-bis(bromomethyl)-2,2′-bipyridine with an amino alcohol prepared from L-tyrosine affords a C₂ 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.