Synthesis of a new class of chiral 1,5-diphosphanylferrocene ligands and their use in enantioselective hydrogenation

摘要

A new family of ferrocenylphosphane ligandshasbeenpropared.Their flexible synthesisallows many structural modifications.The saymmetricinduction of these ligands was examined in the hydrogenation of functionalized C=C,C=O,and C=N bonds.The enantioselectivity of the reaction was strongly dependent on the substituent R at the position #alpha# to the ferrocene moiety.In many cases,both enantiomeric #beta#-hydroxyesters of the reduction product can be obtained by simply replacing a dimethylamino group in the ligand with a methyl group