Search

The commercially available ferrocene-based diphosphine ligand (Sc,SFc)-TaniaPhos was found to be highly effective in the Rh-catalyzed asymmetric hydrogenation of 3-aryl-2-(phosphonomethyl)propenates. Excellent enantioselectivity (90–98% ee) and high catalytic activity (S/C up to 1000) have been achieved, which represents the best results reported so far.

An enantioselective synthesis of chiral alkylphosphonates bearing a beta-stereogenic center, based on the Rh-catalyzed asymmetric hydrogenation of corresponding beta-substituted beta,gamma-unsaturated phosphonates with a ferrocene-based monophosphoramidite ligand under the mild hydrogenation conditions, was developed, in which an ee value of up to 98% was obtained.

A series of chiral ferrocene-based phosphine–phosphoramidite ligands (PPFAPhos) have been employed in the Ag(I)-catalyzed asymmetric [3+2] cycloaddition of azomethine ylides with dimethyl maleate. The results showed that the ligand with a stereogenic P-center in the phosphino moiety displayed the best diastereo- and enantioselectivities, in which up to 99% enantiomeric excesses and 99/1 endo/exo selectivities have been achieved.

A series of chiral beta-substituted alkane-phosphonates was synthesized in high enantioselectivities via the first rhodium-catalyzed asymmetric hydrogenation of the corresponding beta-substituted-alpha,beta-unsaturated phosphonates using a ferrocene-derived rnonophosphoramidite ligand, with which up to 99.5% ee have been achieved for the hydrogenation of (E)-substrates and 98.0% ee for (Z)-substrates.

A series of ferrocene-based phosphine-triazine ligands were successfully employed in the Pd-catalyzed Suzuki - Miyaura crosscoupling reaction of aryl chlorides with arylboronic acids, with ligand 1b was demonstrated to be the most effective one. Under optimized reaction conditions, the catalytic system displayed a remarkable tolerance towards electron-donating substituents and electron-withdrawing substituents. (c) 2007 Published by Elsevier Ltd.

An enantioselective synthesis of chiral alkylphosphonates bearing a β-stereogenic center, based on the Rh-catalyzed asymmetric hydrogenation of corresponding β-substituted β,γ-unsaturated phosphonates with a ferrocene-based monophosphoramidite ligand under the mild hydrogenation conditions, was developed, in which an ee value of up to 98% was obtained.

A series of chiral ferrocene-based phosphine–phosphoramidite ligands (PPFAPhos) have been employed in the Ag(I)-catalyzed asymmetric [3+2] cycloaddition of azomethine ylides with dimethyl maleate. The results showed that the ligand with a stereogenic P-center in the phosphino moiety displayed the best diastereo- and enantioselectivities, in which up to 99% enantiomeric excesses and 99/1 endo/exo selectivities have been achieved.

A series of ferrocene-based phosphine-triazine ligands were successfully employed in the Pd-catalyzed Suzuki - Miyaura crosscoupling reaction of aryl chlorides with arylboronic acids, with ligand 1b was demonstrated to be the most effective one. Under optimized reaction conditions, the catalytic system displayed a remarkable tolerance towards electron-donating substituents and electron-withdrawing substituents. (c) 2007 Published by Elsevier Ltd.