a new ferrocenophane scaffold have been prepared via a stereoselective approach. The P-cyclohexyl substituted phosphine affords high levels of asymmetric induction in the organocatalytic [3 + 2] annulation reaction between allenes and electron-poorolefins.
of bulky P-chiral phosphines with a rigid bicyclic [2.2.1] structure was developed employing a cycloaddition reaction of 3,4,5-triphenyl-1-(+)-neomenthyl-1,2-diphosphole (1) and maleic acid derivatives. The catalytic activity and asymmetric induction for the prepared enantiopure tricyclic phosphines 2a and 3a were evaluated in Pd-catalyzed asymmetricallylic substitution and [3 + 2] organocatalytic
and represents a new motif for chiral ligand design. The syntheses of chiral monophosphines 7 and8 are shown in Figure 2. Halterman 10 and Vollhardt 11 have previously prepared chiral cyclopentadiene derivatives from the chiral diols. Halterman10 has synthesized chiral diols 1 and 2 via Birch reduction12 followed by asymmetric hydroboration. 13 Conversion of the optically pure diols to the corresponding