Synthesis of an Optically Active C1‐Symmetric Al(salalen) Complex and Its Application to the Catalytic Hydrophosphonylation of Aldehydes

Quite universally: The chiral trigonal-bipyramidal Al(salalen) complex 1 was synthesized and found to be an efficient catalyst for enantioselective hydrophosphonylation of various aldehydes with dimethyl phosphite (see scheme). This is the first example where a molecular catalyst can be applied to the reactions of both aromatic and aliphatic aldehydes with enantioselectivities greater than 80 % ee.