Ferrocenylphosphines containing functional groups

Optically active ferrocenylphosphines containing a functional group on the side chain, which may complex to the incoming nucleophile and induce asymmetric attack, have proven to be most effective in ir-aliyl allylations, with optical yields up to 92% being observed (equations 356 and 357).439-442... 

For this type of allylic alkylation, l,3-diphenyl-2-propenyl acetate 39a have been often used as allylic substrates. Although an enantioselectivity of ca. 90% ee has been reported in the reaction of 39 a with acetamidomalonate with usual chiral phosphines such as BINAP or chiraphos [46], the ferrocenylphosphines containing a hydroxyl functionality on the pendant side chain are more effective ligands for the reaction with sodium acetylacetate (Scheme 2-29) [5d, 47]. The enantioselectivity increases as the number of hydroxyl groups on the side chain increases. Thus, the ferrocenylphosphines 8a, 8b, and 8c give the alkylation product with 71, 90, and 96% ee, respectively. High enantioselectivity is also observed in the reaction of l,3-diaryl-2-propenyl acetates (Ar = 1-Np 39b 92% ee, 3-MeOCgH4 39c 86% ee) and ci5-3-acetoxy-5-carbomethoxycyclohexene 40 (72% ee) in the presence of the Pd/(E)-(S)-8b catalyst. 

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