Rendering classical hydrophilic enantiopure Werner salts [M(en) 3 ] n+ n X − lipophilic (M/ n = Cr/3, Co/3, Rh/3, Ir/3, Pt/4); new chiral hydrogen bond donor catalysts and enantioselectivities as a function of metal and charge

Known hydrophilic halide salts of the title compounds are converted to new lipophilic BAr f − (B(3,5-C 6 H 3 (CF 3 ) 2 ) 4 − ) salts. These are isolated as hydrates (Λ- or Δ-[M(en) 3 ] n+ n BAr f − · z H 2 O; z = 17–9) and characterized by NMR (acetone- d 6 ) and microanalyses. Thermal stabilities are probed by capillary thermolyses and TGA and DSC measurements (onset of dehydration 71–151 °C). In the presence of tertiary amines, they are effective catalysts for enantioselective Michael type carbon–carbon or carbon–nitrogen bond forming additions of 1,3-dicarbonyl compounds (acceptors: trans -β-nitrostyrene, di- tert -butylazodicarboxylate, 2-cyclopenten-1-one; average ee = 33%, 52%, 17%). Effects of the metal and charge upon enantioselectivities are analyzed. A number of properties appear to correlate to the NH Brønsted acidity order ([Pt(en) 3 ] 4+ > [Cr(en) 3 ] 3+ > [Co(en) 3 ] 3+ > [Rh(en) 3 ] 3+ > [Ir(en) 3 ] 3+ ).