ChemInform Abstract: Improved Optical Resolution of (R*,R*)‐N,N′‐Dimethyl‐1,2‐diphenylethylenediamine.

Diureas as Ligands in Asymmetric Reduction of Ketones

“…The use of the ( R , R , S , S ) diastereoisomer led to similar activity with a 11% loss in enantioselectivity, which could be due to a mismatch effect (Table , entry 2). Ligands 3e − g derived from N , N ‘-dimethyl-1,2-diphenylethanediamine ( 2 ) and different optically pure diisocyanates were also evaluated. Diastereoisomeric ligands 3e and 3f allowed for complete reduction of propiophenone in 2 weeks with a 21% difference in enantioselectivity (Table , entries 3 and 4).…”