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Recent advances in the synthesis of axially chiral biarylsviatransition metal-catalysed asymmetric C–H functionalization are reported.

The printable polyamide 12 (PA12) nanocomposite filaments with 6 wt % graphene nanoplatelets (GNPs) for fused deposition modeling (FDM) were prepared by melting compounding and smoothly printed via a commercial FDM three-dimensional (3D) printer. The thermal conductivity (k) and elastic modulus (E) of 3D printed PA12/GNPs parts along to the printing direction had an increase by 51.4% and 7% than that of compression molded parts, which is due to the GNPs preferentially aligning along to the printing direction. Along with these improved properties, ultimate tensile strength of 3D printed PA12/GNPs parts was well maintained. These results indicate that FDM is a new way to achieve PA12/GNPs parts with enhanced k over compression moulding, which could contribute to realize efficient and flexible heat management for a wide range of applications.

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A copper-mediated C-S/N-S bond-forming reaction via C-H activation that uses elemental sulfur has been developed. The addition of TBAI was found to be crucial for the success of this transformation. The method is scalable, shows excellent functional group tolerance, and is compatible with heterocycle substrates, providing efficient and practical access to benzoisothiazolones. The direct diversification of the benzoisothiazolone products into a variety of sulfur-containing compounds is also demonstrated.

Due to the lower rotational barriers, the catalytic asymmetric construction of atropisomeric species featuring a five-membered ring remains a formidable challenge. Herein, we describe a Pd-catalyzed atroposelective C−H alkynylation to synthesize such atropisomers. A wide range of atropisomers displaying either a stereogenic C−N or C−C bond featuring one or even two five-membered rings were obtained (up to 98% yield and up to >99% ee). Various five-membered heteroarenes, including pyrroles, thiophenes, benzothiophenes, and benzofurans were compatible with this protocol. Notably, this strategy offers the catalytic asymmetric synthesis of axially chiral 3,3′-bisbenzothiophene with good ee (93% ee). Computational studies revealed the key structural elements that differentiate the rotational barriers of benzothiophene and benzofuran moieties.

Chiral aldehyde catalysis opens new avenues for the activation of simple amines. However, the lack of easy access to structurally diverse chiral aldehyde catalysts has hampered the development of this cutting‐edge field. Herein, we report a Pd‐catalyzed atroposelective C−H naphthylation with 7‐oxabenzonorbornadienes for the preparation of axially chiral biaryls with excellent enantioselectivities (up to >99 % ee). This reaction is scalable and robust, which serves as a key step to provide a rapid access to axially chiral aldehyde catalysts through a three‐step C−H functionalization sequence. These chiral aldehydes exhibit better activities and enantioselectivities than the previously reported organocatalysts in the asymmetric activation of glycine derived amides and dipeptides. Moreover, preliminary investigation also discloses that the aldehyde catalyst can effectively override the intrinsic facial selectivity of chiral dipeptide substrates, showcasing the strong chiral induction ability of this type of novel aldehyde catalysts.

The discovery of proper ligands to simultaneously modulate the reactivity and effectively control the stereoselectivity is a central topic in the field of enantioselective C−H activation. Herein, we reported the synthesis of axially chiral biaryls by Pd‐catalyzed atroposelective C−H olefination. A novel chiral spiro phosphoric acid, STRIP, was identified as a superior ligand for this transformation. A broad range of axially chiral quinoline derivatives were synthesized in good yields with excellent enantioselectivities (up to 98 % ee). Density functional theory was used to gain a theoretical understanding of the enantioselectivities in this reaction.