Application of a new class B-podands in solid-liquid phase transfer catalysis

As a continuation of our earlier systematic study, this paper reports on the performance of boron polypodands 1-8 (B-podands) as catalysts in a series of anion promoted reactions (nucleophilic substitution, reduction, N- and O-alkylation) in chlorobenzene, toluene and acetonitrile solutions carried out in the solid-liquid (SL) phase transfer catalysis (PTC) conditions. Comparison of the catalytic efficiency (expressed by observed rate constants) of 1-8 with that of well known classical phase transfer catalysts: crown ethers, polyethylene glycols (PEG) (9, 10) and previously studied Si-podands (11, 12) is also included.