Complexation and Pd-catalyzed asymmetric allylation with participation of chiral ferrocenyliminophosphites

Chiral ferrocene-containing iminoarylphosphite ligands based on 4,4'-dimethoxy-6,6'-di-tertbutyl-biphenyidiol-2,2' and their chelate complexes with Rh(I) and Pd(II) were synthesized for the first time. They were shown to be perspective reagents in the reactions of asymmetric allyl substitution. The Pd-catalyzed alkylation of 1,3-diphenylailylacetate with dimethyl malonate results in a 87% enantiomer excess (ee), while in sulfonylation of 1,3-diphenylallylacetate with sodium para-toluenesulfinite, this figure amounts to 67%. The results obtained were compared with coordination and catalytic efficiency of a less sterically hindered ferrocenyliminophosphite based on pyrocatechol. The compositions and structures of new compounds were determined by the H-1, C-13, P-31 NMR, IR, mass spectrometry (EI, FAB, and electrospray techniques), and elemental analysis.