Sulfonic acid supported on hydroxyapatite-encapsulated-γ-Fe 2O3 nanocrystallites as a magnetically separable catalyst for one-pot reductive amination of carbonyl compounds
A novel, environmentally friendly procedure has been developed for the preparation of secondary or tertiary amines by one-pot reductive amination of carbonyl compounds using sodium borohydride in the presence of a magnetically recoverable sulfonic acid supported on hydroxyapatite-encapsulated-γ- Fe2O3 [γ-Fe2O3@HAP-SO 3H] at room temperature. The catalyst was easily separated from the reaction mixture by applying an external magnet and reused for six cycles without significant loss of catalytic activity.
(E,E,E)-4,4′-distyrylstilbenes - Synthesis, photophysics, photochemistry and phase behavior
The fluorescence quantum yields φF(n) of oligo[2,5-bis(propyloxy)-1,4-phenylenevinylene]s (1b) reach for the trimer (n = 3) in solution a maximum of 86%, which is almost twice as high as for the monomer (n = 1) and the octamer or undecamer (n =