(Diphenylphosphino)-biheteroaryls: the first example of a new class of chiral atropisomeric chelating diphosphine ligands for transition metal catalysed stereoselective reactions

Abstract

Ruthenium(II) dichloride complexes with (+)- and (–)-2,2′-bis(diphenylphosphino)-4,4′,6,6′-tetramethyl-3,3′-bibenzo[b]thiophene (1a), new chiral atropisomeric heterocyclic ligands, reduce α- and β-oxoesters to α- and β-hydroxyesters with an enantiomeric purity comparable, if not higher, to that reported for binap under the same experimental conditions.