An Enantioselective Oxidative C–H/C–H Cross-Coupling Reaction: Highly Efficient Method To Prepare Planar Chiral Ferrocenes

A Pd-catalyzed, asymmetric oxidative cross-coupling reaction between ferrocenes and heteroarenes is described. The process, which takes place via a twofold C–H bond activation pathway, proceeds with modest to high efficiencies (36–86%) and high levels of regio- and enantioselectivity (95–99% ee). In the reaction, air oxygen serves as a green oxidant and excess amounts of the coupling partners are not required. The process is the first example of a catalytic asymmetric biaryl coupling reaction that occurs via double C–H bond activation. Finally, the generated coupling products can be readily transformed into chiral ligands and catalysts

An Enantioselective Oxidative C–H/C–H Cross-Coupling Reaction: Highly Efficient Method To Prepare Planar Chiral Ferrocenes

A Pd-catalyzed, asymmetric oxidative cross-coupling reaction between ferrocenes and heteroarenes is described. The process, which takes place via a twofold C–H bond activation pathway, proceeds with modest to high efficiencies (36–86%) and high levels of regio- and enantioselectivity (95–99% ee). In the reaction, air oxygen serves as a green oxidant and excess amounts of the coupling partners are not required. The process is the first example of a catalytic asymmetric biaryl coupling reaction that occurs via double C–H bond activation. Finally, the generated coupling products can be readily transformed into chiral ligands and catalysts

An Enantioselective Oxidative C–H/C–H Cross-Coupling Reaction: Highly Efficient Method To Prepare Planar Chiral Ferrocenes

A Pd-catalyzed, asymmetric oxidative cross-coupling reaction between ferrocenes and heteroarenes is described. The process, which takes place via a twofold C–H bond activation pathway, proceeds with modest to high efficiencies (36–86%) and high levels of regio- and enantioselectivity (95–99% ee). In the reaction, air oxygen serves as a green oxidant and excess amounts of the coupling partners are not required. The process is the first example of a catalytic asymmetric biaryl coupling reaction that occurs via double C–H bond activation. Finally, the generated coupling products can be readily transformed into chiral ligands and catalysts

Pd(II)-Catalyzed Intermolecular Direct C–H Bond Iodination: An Efficient Approach toward the Synthesis of Axially Chiral Compounds via Kinetic Resolution

An efficient protocol to synthesize axially chiral compounds via kinetic resolution by Pd­(II)-catalyzed direct C–H iodination was realized (up to <i>s</i> = 27). The iodide product could be easily transformed to aryl-substituted pyridine <i>N</i>-oxides via the Suzuki–Miyaura coupling, which proved to be a suitable catalyst in asymmetric allylation of benzaldehyde with allyl­trichloro­silane

Pd-Catalyzed Highly Enantioselective Synthesis of Planar Chiral Ferrocenylpyridine Derivatives

A highly efficient synthesis of planar chiral ferrocenylpyridine derivatives via Pd-catalyzed intramolecular C–H arylation was developed, and quantitative yields and excellent enantioselectivity were obtained for a wide range of substrates. Notably, the catalyst loading could be lowered to 0.2 mol %, which represents the highest catalytic efficiency found for asymmetric C–H bond activation (TON up to 495). These compounds could be easily transformed to pyridine <i>N</i>-oxides, displaying promising catalytic reactivity in the asymmetric opening of <i>meso</i>-epoxide. Moreover, computational investigations were conducted to clarify the origin of the excellent enantioselectivity. The compatibility of large-scale synthesis and low catalyst loading should enhance the practicality of the synthetic application of the current method

Enantioselective Synthesis of Planar Chiral Ferrocenes via Pd(0)-Catalyzed Intramolecular Direct C–H Bond Arylation

A highly efficient synthesis of planar chiral ferrocenes by enantioselective Pd(0)-catalyzed direct C–H arylation from readily available starting materials under mild reaction conditions was developed (up to 99% yield, 99% ee). The products can be easily transformed to the highly efficient planar ferrocene ligands, which have demonstrated high efficiency in Pd-catalyzed asymmetric allylic alkylation and amination reactions

Palladium(0)-Catalyzed Asymmetric C–H Alkenylation for Efficient Synthesis of Planar Chiral Ferrocenes

Pd­(0)-catalyzed intramolecular C–H alkenylation was achieved with excellent yields and enantioselectivity for the construction of planar chiral ferrocenes. It is compatible with a broad range of substrates and various functional groups. Notably, the enantioselective and diastereoselective synthesis of planar chiral ferrocenes was realized by cascade C–H arylation and alkenylation reaction for the first time. Additionally, the product was easily converted into a <i>N</i>,<i>O</i>-bidentate ligand, showing promising chiral induction in asymmetric alkynylation of 1-naphthaldehyde

Palladium(0)-Catalyzed Asymmetric C–H Alkenylation for Efficient Synthesis of Planar Chiral Ferrocenes

Pd­(0)-catalyzed intramolecular C–H alkenylation was achieved with excellent yields and enantioselectivity for the construction of planar chiral ferrocenes. It is compatible with a broad range of substrates and various functional groups. Notably, the enantioselective and diastereoselective synthesis of planar chiral ferrocenes was realized by cascade C–H arylation and alkenylation reaction for the first time. Additionally, the product was easily converted into a <i>N</i>,<i>O</i>-bidentate ligand, showing promising chiral induction in asymmetric alkynylation of 1-naphthaldehyde

Catalytic, Enantioselective Synthesis of Allenyl Boronates

A method to achieve enantioselective 1,4-hydroboration of terminal and internal enynes to access allenyl boronates under CuH catalysis is described. The reaction typically proceeds in a highly stereoselective manner and tolerates an array of synthetically useful functional groups. The utility of the enantioenriched allenyl boronate products is demonstrated through several representative downstream derivatizations

Catalytic, Enantioselective Synthesis of Allenyl Boronates

A method to achieve enantioselective 1,4-hydroboration of terminal enynes to access allenyl boronates under CuH catalysis is described. The reaction typically proceeds in a highly stereoselective manner and tolerates an array of synthetically useful functional groups. The utility of the enantioenriched allenyl boronate products is demonstrated through several representative downstream derivatizations