The development of efficient and straightforward methods for obtaining all optically active isomers of structurally rigid spirocycles from readily available starting materials is of great value in drug discovery and chiral ligand development. However,t he stereodivergent synthesis of spirocycles bearing multiple stereocenters remains an unsolved challenge owing to steric hindrance and ring strain. Herein, we report an enantioand diastereodivergent synthesis of rigid spirocycles through dual-metal-catalyzed [3+ +2] annulation of oxy p-allyl metallic dipoles with less commonly employed nucleophilic dipoles (imino esters). Aseries of spiro compounds bearing apyrroline and an olefin were easily synthesized in an enantio-and diastereodivergent manner (up to 19:1 dr, > 99 %e e), which showed great promise as an ew type of N-olefin ligand. Preliminary mechanistic studies were also carried out to understand the process of this bimetallic catalysis.

A phosgene- and metal-free synthesis of O-aryl carbamates is realized through a three-component coupling of carbon dioxide, amines and diaryliodonium salts. The reaction only requires a base as the promoter, providing access to a diverse array of O-aryl carbamates in moderate to high yields with excellent chemoselectivity.

The first base-promoted formal [4 + 3] annulation between 2-fluorophenylacetylenes and ketones has been disclosed. The reaction proceeds through a tandem α-vinylation of ketones followed by an intramolecular nucleophilic aromatic substitution (SNAr) reaction of the in situ generated β,γ-unsaturated ketone intermediates, providing a straightforward access to a wide range of functionalized benzoxepines in moderate to high yields. The transition-metal-free methodology featured a wide substrate scope, the use of easily available starting materials, and a high functional group tolerance.

The first asymmetric Ni/Cu cocatalyzed benzylation of aldimine esters is reported. A series of benzylsubstituted α-quaternary amino acids could be synthesized in high yield and with high levels of enantioselectivity (up to 90 % yield and 99 % ee). The experimental and theoretical calculation results suggested that the strong electrophilicity of the η 3 -benzylnickel intermediate is crucial for the high reactivity, enabling the reaction under base-free conditions. Furthermore, this method has been applied to the synthesis of the cell adhesion inhibitor BIRT-377 analogues, and the key intermediate of the NK1 receptor antagonist PD154075 and CCK-B receptor antagonist CI-988.

The first nBuNI-catalyzed oxidative cross-coupling reaction of carbon dioxide, amines and arylketones has been successfully developed by using TBHP as the oxidant, providing an efficient, atom-economical and metal-free strategy for the synthesis of a range of O-β-oxoalkyl carbamates.

A copper-catalyzed [2 + 3] formal cyclization reaction between α-hydroxyl ketones and arylacetonitriles has been developed. The reaction outcome was ultimately dependent on the structure of the α-hydroxy ketones employed. Tertiary α-hydroxy ketones gave 3,4,5,5-tetrasubstituted butenolides as the sole products, while secondary α-hydroxy ketones furnished 2,4,5-trisubstituted oxazoles selectively. This method has many advantages, such as the use of easily available substrates, broad substrate scope, good functional tolerance, and milder reaction conditions.

A base‐promoted nucleophilic addition of arylacetonitriles to terminal alkynes has been described for the first time, providing a simple and straightforward protocol for the synthesis of a range of structurally diverse (Z)‐2,3‐disubstituted acrylonitriles in moderate to excellent yields. Of particular note, the transition metal‐free carbon‐carbon double bond forming reaction is regio‐ and stereoselective under mild conditions. A variety of functional groups can be tolerated on both the arylacetonitrile substrate and the alkyne coupling partner. Moreover, the reaction is easily scalable and the products thus obtained can serve as versatile intermediates for the synthesis of a series of useful substances.magnified image

Disubstituted oxindoles bearing quaternary and tertiary stereogenic centers are privileged structural motifs, which widely exist in pharmaceutical and natural products. Herein, a highly regio-, enantio-, and diastereoselective allylic alkylation of 3-alkyl oxindoles through synergistic iridium and copper catalysis is described, which provides a series of 3,3-disubstituted oxindole derivatives containing adjacent quaternary and tertiary stereogenic centers in excellent yields, enantiomeric excess, and diastereomeric ratio (for 30 examples, up to 97 % yield, > 99 % ee, and > 20 : 1 dr). This method provides exclusive branched selectivity, excellent enantio-and diastereoselectivities, and good functional compatibility. Control experiments suggested that the chiral copper catalyst is required for achieving high reactivities and diastereoselectivities under mild reaction conditions.