in tetrahydrofuran (N2 or Ar), 25°C, stirring for 30 min in a round-bottom flask; solvent is removed under reduced pressure, extd. with pentane, chromy. on silica gel(CH2Cl2), determined by (55)Mn-NMR;

in tetrahydrofuran (N2 or Ar), 25°C, stirring for 30 min in a round-bottom flask; solvent is removed under reduced pressure, extd. with pentane, chromy. on silica gel(CH2Cl2), determined by (55)Mn-NMR;