Asymmetric allylation ferrocenylphosphine

The ferrocenylphosphine (R)-(S)-8a is also effective for the asymmetric allylation of several other active methine compounds, including 2-acetyl-1-tetralone, 6,6-dimethyl-2-acetylcyclohexanone, 2-acetylcyclooctanone, 1 -phenyl-2-methylbutane-1,3-dione, 2-phenylpropanal, and methyl a-isocyano(phenyl)acetate [43, 44], The allylation products and the values of enantiomeric excess are shown in Scheme 2-26. 

Intramolecular asymmetric allylic substitution reactions have been applied to the synthesis of optically active cyclic compounds. The high efficiency of the dihydroxylated ferrocenylphosphine 8b has been shown in the cyclization of 2-butenylene dicarbamates 52 to form optically active 4-vinyl-2-oxazolidones 53, which are... 

Some ferrocenylphosphine-amidine ligands (Figure 3.6) with central and planer chirality were prepared and their efficiency and diastereomeric impact in the palladium catalysed asymmetric allylic substitution were examined [75]. Up to 96% ee with 98% yield was achieved by the use of a ligand with a methyl-substituted ligand. 

Hu, X., Chen, H., Hu, X. er a/. (2002) Synthesis of novel ferrocenylphosphine-antidine ligands and their application in Pd-catalysed asyrmnetric allylic alkylation. Tetrahedron Letters, 43, 9179-9182 Hu, X., Chen, H., Dai, H. ef a/. (2003) S3mthesis of novel ferrocenylphosphine-amidine ligands with central and planar chirality and their diastereomeric effect in Pd-catalysed asymmetric allylic alkylation. Tetrahedron Asymmetry, 14, 2073-2080. 

An asymmetric preparation of alkenylcyclopropanes has also been realized by the use of palladium(O) complexes carrying chiral ferrocenylphosphine ligands (equation 22)38. The requisite rt-allyl palladium intermediates can also be generated from allene and meth-ylenecyclopropane derivatives, 1839 and 1940, in the presence of palladium(O) complex and alkenyl or aryl halide (equations 23 and 24). The cobalt complexes, 20, similarly afford the corresponding alkenylcyclopropanes upon exposure to LDA (equation 25)41. 

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... 

Other reports include the kinetic resolution of racemic allylic acetates in an asymmetric alkylation reaction catalysed by chiral ferrocenylphosphine palladium complexes and the use of the ferrocenyl group in peptide chemistry. ... 

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