Wen-Hua Zheng

Electrophilic selenium catalysis has recently emerged as an attractive synthetic strategy, yet the field of enantioselective electrophilic selenium catalysis remains underdeveloped, primarily due to the scarcity of efficient chiral catalysts and limited reaction types. Herein, we disclose the design and synthesis of a series of planar chiral organoseleniums based on [2.2]paracyclophane. With these chiral organoseleniums as catalysts, we accomplish a highly enantioselective intramolecular oxidative etherification of trisubstituted olefins, providing a diverse array of optically pure chromans bearing a quaternary carbon stereocenter. The stereochemical versatility of this method enables efficient access to both product enantiomers from the same catalyst by adjusting the E/Z configurations of the olefins. Importantly, comprehensive control experiments and kinetic studies elucidate the reaction mechanism, identifying the oxidation of selenenylated cyclic ether as the likely turnover-limiting step. DFT calculations demonstrate that both steric hindrance and weak interactions play a vital role in enantioselectivity.

The asymmetric ring-opening of aliphatic cyclic carbonates represents a strategically important, yet challenging, transformation for accessing chiral building blocks and polymeric materials. Herein, we present a novel methodology enabling the enantioselective desymmetrization of aliphatic cyclic carbonates using morpholine as the nucleophile and chiral bicyclic guanidinium salt as the catalyst under mild conditions. The protocol exhibits exceptional substrate tolerance, providing a diverse array of alkyl- and aromatic-substituted products with excellent yield and high enantioselectivity (97:3). Notably, it also enables the parallel kinetic resolution of racemic unsymmetrical alkyl-substituted cyclic carbonates with superior selectivity. The stereochemical outcome is supported by density functional theory (DFT) studies, which reveal a cooperative mechanism involving chiral guanidinium cation-solvent interactions that stabilize the transition state for the enantioselective 1,3-proton transfer step.

Axial chiral biaryl skeletons are widely found in biologically active molecules, catalysts and chiral functional materials. However, highly catalytic stereoselective synthesis of tetra‐ ortho ‐substituted biaryls remains a challenging task. In this paper, we describe an efficient approach for construction of axially tetra‐ ortho ‐substituted biaryls via Suzuki‐Miyaura coupling in the presence of a chiral monophosphate ligand developed by ourselves. This method provides a variety of products in good enantioselectivities and good yields (up to 90.7 : 9.3 er and 82 % yield) under mild conditions. Further control experiments indicate that the chiral side chain is crucial to the enantioselectivity.

Through partially carbonizing the condensation polymer CB, the Cu–CB-180 catalyst achieved excellent enantioselectivity and recyclability in heterogeneous asymmetric Henry reaction.

Chiral self‐assembly has often been found to be an efficient strategy for the development of high‐performance circularly polarized luminescent (CPL) materials, through the regulation of the ordered helical superstructure blocks in liquid crystal media. Here, the design and synthesis of two pairs of axially chiral emitters (BBXT‐3‐Br and BOHXT‐3‐Br) are reported based on bromoxanthone. And the chiral self‐assembled liquid crystal polymer (LCP) framework (PRM257) is demonstrated by mixing of the emitters with liquid crystal monomer (RM257) through thermal annealing and photoinitiated polymerization. Both BBXT‐3‐Br@PRM257 and BOHXT‐3‐Br@PRM257 exhibited excellent room temperature phosphorescence (RTP) properties. In addition, BBXT‐3‐Br@PRM257 enantiomers showed afterglow with an average lifetime (τ) of 162.41 ms and emitted blue CPL (λ_em = 450 nm, Φ_FL = 1.3%, |g_FL| = 0.071), although weak circularly polarized RTP (CP‐RTP) is observed. Interestingly, BOHXT‐3‐Br@PRM257 with a less conjugated system emits red RTP (τ = 98.83 ms) and also intense CP‐RTP (λ_em = 612 nm, Φ_Phos = 0.45%, |g_RTP| = 0.057).

Herein, we describe our design and synthesis of novel chiral monophosphine ligands by the short-step addition of chiral lactates as side chains to the well-known ligand SPhos/RuPhos. The new chiral ligands were shown to be highly efficient in palladium-catalyzed Suzuki-Miyaura coupling, providing a series of axially chiral biphenyl products in high yield and high enantioselectivity. Furthermore, the gram-scale reaction and the diverse conversions of the products demonstrated the potential utility of the approach.

In this paper, planar chiral helicenes based on [2.2]paracyclophane PCPH5 acted as both chiral inducers and energy donors to construct the circularly polarized luminescence (CPL)-active ternary cholesteric liquid crystals (T-N*-LCs) in a commercial nematic liquid crystal (SLC1717, N-LCs) medium. Induced red CPL emission based on the energy acceptor of the achiral polymer DTBTF8 could be successfully promoted by the intermolecular Förster resonance energy transfer mechanism. The resulting T-N*-LCs can generate intensive CPL signals with g_lum up to +0.70/-0.67. Interestingly, this kind of "on-off" CPL switching of T-N*-LCs can be manipulated by the applied direct current electric field.

Notwithstanding the common use of boronic acids in catalysis, the design and synthesis of efficient chiral boronic acids remains a formidable challenge. Herein we disclose a rational design and a concise synthesis of a series of novel C₂-symmetric disubstituted boronic acids, or borinic acids. Chiral borinic acids have been found to be excellent agents that can achieve highly enantioselective desymmetrization of 2,2-disubstituted-1,3-propanediols, providing chiral diols with a quaternary stereocenter, which has been regarded in recent years as challenging. A wide range of substrates are tolerated in this reaction, providing a series of chiral diols with high enantioselectivity. The presence of the tetracoordinate borinate in the catalytic cycle has been proven by ¹¹B NMR studies, and a stereocontrol model has been proposed.