Turning the Nitrogen Atoms of an Ar2 P-CH2 -N-N-CH2 -PAr2 Motif into Uniquely Configured Stereocenters: A Novel Diphosphane Design for Asymmetric Catalysis.

Hexahydropyridazines with CH2 PAr2 groups at both N atoms are newly designed 1,4-diphosphanes and were synthesized for the first time. Their N atoms assume a single configuration under the influence of stereocenters at C-5 and C-6. In the solid state, these N-atoms bind the CH2 PAr2 substituents axially. Combined with Pd0 , N,N'-chiral diphosphanes of this kind catalyzed Tsuji-Trost type allylations of dialkyl malonates with racemic 1,3-diphenylallyl acetate efficiently and with up to 91 % ee.