Thioesters & Thionolactones
Our work in this field began with molybdenum and tungsten complexes of dithioesters (see Metal Carbonyls). Lateron we have taken this subject up again with a specific goal: Complexes of certain biaryl-thionolactones are expected to undergo ring-opening upon nucleophilic attack .
If such reactions are carried out with similar but chiral complexes it may be expected that the ring-opened, conformationally stable biaryl compound is obtained selectively in one of the two enantiomeric forms. This has indeed been accomplished [83, 86, 97, 99]. The structures of one of the starting materials as well as an important intermediate shown below provide clues to the origin of the diastereoselectivity of this reaction sequence.