Chiral diphenylselenophosphoramides: a new class of chiral ligands for thetitanium(IV) alkoxide-promoted addition of diethylzinc to aldehydes

Chiral C-2-symmetric diphenylselenophosphoramides 1 and 2 were prepared fro m the reaction of diphenylselenophosphinic chloride with(1R,2R)-(-)-1,2-dia minocyclohexane and(1R,2R)-(+)-1,2-diphenylethylenediamine, respectively, i n high yields. Another novel chiral ligand 3 was prepared from the reaction of diphenylselenophosphinic chloride with (R)-(+)-1,1'-binaphthyl-2,2'-dia mine using butyllithium as the base. The ligands were used as catalytic chi ral ligands in the titanium(IV) alkoxide-promoted enantioselective addition reaction of diethylzinc to aldehydes. (C) 2000 Elsevier Science Ltd, All r ights reserved.