Synthesis and Application of New Salan Titanium Complexes in the Catalytic Reduction of Aldehydes.

Complexes of formula [(H 2 N 2 O 2 )TiCl 2 ] and [(H 2 N 2 O 2 )Ti(O i Pr) 2 ] (H 2 N 2 O 2 H 2 = HOPh'CH 2 NH(CH 2 ) 2 NHCH 2 Ph'OH, where Ph' = 2,4-(CMe 2 Ph)C 6 H 2 ) were synthesized by the reaction of the salan ligand precursor H 2 N 2 O 2 H 2 with TiCl 4 and Ti(O i Pr) 4 , respectively, in high yields. The dichlorido complex [(H 2 N 2 O 2 )TiCl 2 ] revealed to be an efficient catalyst for the reduction of benzaldehyde in toluene. Full conversion was observed after 24 h at 55 °C in THF. The same catalyst also converted phenylacetaldehyde and hydrocinnamaldehyde into the corresponding alkanes quantitatively.