Juan Jose Almena Perea

A versatile modular approach to new chiral C2-symmetrical ferrocenyl ligands: Highly enantioselective Rh-catalyzed hydrogenation of α-acetamidoacrylic acid derivatives☆

Abstract An easy, efficient, flexible modular synthesis of a new family of chiral C 2 -symmetrical ferrocenyl diphosphines (FERRIPHOS) is described. These new ligands gave high enantioselectivities (up to 99.4% ee ) in the rhodium-catalyzed hydrogenation of different enamide derivatives.

Synthesis and application of C2-symmetric diamino FERRIPHOS as ligands for enantioselective Rh-catalyzed preparation of chiral α-amino acids

Abstract C 2 -Symmetrical ferrocenyl diamino diphosphines (diamino FERRIPHOS ligands) proved to be excellent ligands for the rhodium-catalyzed enantioselective reduction of methyl α-acetamidoacrylates. The straightforward synthesis, their air stability and the easy modification of their structure makes these ligands especially interesting for transition metal-catalyzed hydrogenations. α-Amino acids with enantioselectivities greater than 95% (and up to 99.3% ee ) were obtained with no need of further recrystallization.

Stereoselective substitution of α-aminoalkylferrocenes with diorganozincs. A fast synthesis of new chiral FERRIPHOS ligands for asymmetric catalysis

Abstract A direct stereoselective substitution of α-aminoalkylferrocenes of type 3 with organozinc reagents provides chiral ferrocenes which can be converted to the FERRIPHOS ligands of type 1 in a one-pot procedure. These FERRIPHOS ligands have been used for the Rh-catalyzed asymmetric hydrogenation of an enol acetate with 94.9% ee .

Substitution of ferrocenyl acetates with organozinc reagents. An enantioselective preparation of polyfunctional chiral ferrocenes

Abstract The substitution reaction of α-ferrocenyl acetates with diorganozincs or reactive organozinc halides in the presence of BF 3 ·OEt 2 in THF (−78 °C to rt, 1.5 h) provides new α-chiral ferrocenes with retention of configuration (95–100 % retention).

Synthesis and Stereoselective Reactions of New Stableα-Ferrocenyllithium Derivatives. An Umpolung of the Ferrocene Reactivity

The reductive lithiation of various α-ferrocenylcarbinol derivatives yields stable α-ferrocenyllithium species (see scheme). These can be quenched with different electrophiles with complete retention of configuration.

Synthese und stereoselektive Reaktionen neuer stabiler α‐Ferrocenyllithiumderivate – Umpolung der Ferrocenreaktivität

Durch reduktive Lithiierung von α-Ferrocenylcarbinolderivaten sind stabile α-Ferrocenyllithiumverbindungen leicht zuganglich. Sie konnen mit Elektrophilen unter Retention der Konfiguration abgefangen werden. Eine beispielhafte Reaktionssequenz ist gezeigt.