Although a considerable number of chiral nitrogen heterocyclic carbenes (NHCs) have been developed yet it is highly necessary to develop new NHCs bearing multiple sites for facile modifications of both electronic nature and steric hindrance. Herein, we uncover a new family of chiral non-C-2-Symmetric NHCs with a fused sidechain, whose precursors are synthesized by a simple five-step route. The synthesis includes Pd-catalyzed cross-coupling or nucleophilic addition/oxidation, chiral phosphoric acid-catalyzed asymmetric reduction of 2-aryl-quinolines, bromination at C8, Buchwald-Hartwig amination, and cyclization with methyl orthoformate. Among nine prepared NHCs, YC-NHC8 is the optimal ligand for Cu(I)-catalyzed asymmetric S(N)2 ' silylation, YC-NHC3 works as the best ligand for Cu(I)-catalyzed enantioselective conjugate silylation of simple alpha,beta-unsaturated amides, and YC-NHC9 serves as the most suitable ligand for copper(I)-catalyzed asymmetric silylation of azadienes. Remarkably, these three reactions are successfully run under a catalyst loading of 0.1 mol%, indicating that YC-NHCs may have the potential to be broadly used in efficient asymmetric transition metal catalysis.

The use of metal for catalytic difluorocarbene transfer reactions has long been hindered by the lack of understanding of metal difluorocarbene chemistry, despite the potential implications for medicinal chemistry and advanced materials science. Here, we report a copper-catalyzed difluorocarbene transfer reaction via 1,1-migration of copper difluorocarbene, in contrast to the previous nucleophilic addition of copper difluorocarbene pathway. This reaction enables the development of a modular catalytic gem-difluoropropargylation reaction using a variety of simple and widely available potassium propiolates, terminal alkynes, and allyl/propargyl electrophiles to couple difluorocarbene, opening an avenue to the precise synthesis of organofluorine compounds without tedious synthetic procedures. The impact of this protocol is demonstrated by the efficient synthesis of complex fluorinated skeletons and the rapid synthesis of key intermediates for pheromone derivatives and PGF2 agonists. Mechanistic studies reveal that the migratory insertion of difluorocarbene into the C-Cu bond of the alkynylcopper species is a key step in the reaction.

Lasso peptides, a unique class of ribosomally synthesized and post-translationally modified peptide (RiPP), are challenging to synthesize chemically, making the discovery of new peptides and their biosynthetic pathways essential. This study reports the discovery and characterization of a novel lasso peptide, actinosynnelassin, from Actinosynnema pretiosum subsp. auranticum DSM 44131. By overexpressing an endogenous TetR/AcrR family regulator and employing OSMAC (One Strain Many Compounds)-guided fermentation screening, several endogenous secondary metabolite biosynthetic gene clusters (BGCs) were activated, resulting in the isolation of actinosynnelassin. The 3D structure of actinosynnelassin, confirmed by nuclear magnetic resonance (NMR) NOE-derived distance constraints, features a 9-aa macrolactam ring, a 6-aa loop, and a 2-aa tail, with the ring encircling the tail between three aromatic bulkier residues. The minimal inhibitory concentration (MIC) tests indicate that actinosynnelassin inhibits several Gram-positive bacteria and Pseudomonas fluorescens, making it the first reported lasso peptide to inhibit P. fluorescens. The predicted open reading frame (ORF) of the precursor peptide may be translated into a 331-aa fusion protein featuring an N-terminal AraC/XylS family transcriptional regulator, making it longer than typical lasso precursors. Thus, discovering this large precursor ORF enhances our understanding of lasso peptide BGCs with unusual architectures and enables the finding of other unique lasso peptides.

Ambiguine P (5) is a synthetically challenging representative of the hapalindole-type natural products. Inspired by the biosynthesis of this indole terpenoid family, we developed a Cope/Prins/Friedel-Crafts cascade, achieving a six-step synthesis of 5 from 2,2-dimethylcycloheptanone. Altered from the biosynthetic pathway, this cascade strategically commenced with a tricyclic indolenine derivative bearing a seven-membered ring, enabling efficient construction of the pentacyclic scaffold of 5. The oxidation state was elevated through chlorination and hydroxylation in the final stage.

Despite significant advancements in the use of composite materials derived from metal-organic frameworks (MOFs) for electromagnetic wave absorption, achieving the inherent electromagnetic shielding properties of MOFs remains challenging. This is because reflection loss dominated electromagnetic shielding materials typically exhibit extremely high conductivity, whereas intrinsic MOFs are generally insulators. Furthermore, excessive reflection loss arising from high conductivity will cause secondary electromagnetic pollution, severely disrupt communication equipment and endanger human health. Here, we successfully synthesized two conductive MOFs and directly used for electromagnetic shielding. Due to the strong polarization effect, moderate conductivity, and anisotropic 1D chain structure, an effective shielding (SET) of CuMOF-1D of 34.08 dB is achieved, surpassing 20 dB within the 1-18 GHz range, and a high absorption loss (SEA) of 29.75 dB is demonstrated with a low reflection loss (SER) of 4.33 dB. The SEA/SET value reaches 87.3%, and the green shielding index is 0.83. These findings not only accentuate the importance of CuMOF-1D as a green electromagnetic shielding material that preponderantly relies on absorption loss but also emphasize the latent potential of intrinsic conductive MOFs to serve as a gene tailoring platform.

A Pd-catalyzed one-pot regioselective difunctionalization of 3-iodo-o-carborane has been achieved for the synthesis of a wide variety of 3-alkyl-4-Nu-o-carboranes (Nu = aryl, alkyl, amino, or thio groups) in moderate to excellent yields. This protocol combines the sequential activation of cage B(3)-I and B(4)-H bonds via Pd 1,4-migration.