1,3,5-Triamino-2,4,6-trinitrobenzene (TATB) has excellent stability and very low mechanical sensitivity and is used as an important component in polymer binder explosive (PBX) for nuclear weapons. However, at present, the methods of industrial preparation of TATB have problems such as low efficiency and residual impurities. Based on a new method to synthesize TATB from phloroglucinol, we developed a continuous and efficient method for preparing 1,3,5-triethoxy-2,4,6- trinitrobenzene (TETNB), the key intermediate to synthesize TATB. In view of the importance of this reaction, in-depth theo-retical research on the reaction mechanism has been conducted with the Gaussian 16 software at the M062X/6-31+G** lev-el. The reaction mechanism and the thermodynamic equilibrium of the etherification process were clarified. Under the cataly-sis of protic acid, triethyl orthoformate eliminates one ethanol molecule to form a diethoxy-carbocation intermediate. Since the lone pair electrons of the adjacent oxygen atoms can partially fill the empty p orbital of the carbocation, the dieth-oxy-carbocation intermediate is relatively stable. Subsequently, there are two reaction modes for diethoxy-carbocation. In thefirst mode, trinitrophloroglucinol (TNPG) anion acts as a nucleophile to attack the diethoxy-carbocation intermediate in SN2 fashion, grabbing an ethyl carbocation and achieving the alkylation. In this mode, the diethoxy-carbocation intermediate di-rectly provides an alkyl carbocation. In the second mode, addition reaction occurs between the TNPG negative ions and the diethoxy-carbocation intermediate to produce new orthoformate, which can be regarded as transesterification. Then, the eth-anol molecule conducts an aromatic nucleophilic substitution (SNAr) to replace the diethyl orthoformate on the aromatic ring and complete the alkylation. In comparison, diethyl orthoformate is a relatively better leaving group. In addition, this etheri-fication reaction has a remarkable feature: the thermodynamic stability of the product is slightly worse than that of the reac-tants. Therefore the yield is lower when chemical equilibrium is reached. This requires continuous removal of the by-products of the system in the experiment to pull the chemical balance toward the direction of the product

An efficient method for synthesizing sulfonyl fluorides by fluorinating sulfonyl hydrazides with 10 % F2/N2 was developed. This transformation demonstrated a broad substrate scope, yielding a series of sulfonyl fluorides in moderate to good yields. Additionally, a 10 g scale experiment was conducted, demonstrating the practicality of this method.

Oxazoline and spirocyclohexadienone moieties are prevalent in natural products and biologically active molecules. Herein, we report an efficient method for the synthesis of oxazoline-spirocyclohexadienones via electrochemistry-mediated oxidative dearomatization of phenol derivatives, utilizing amide side chains as nucleophiles. This approach features the employment of anodic oxidation strategy, circumventing the need for traditional oxidizing agents. A diverse range of oxazoline-spirocyclohexadienones are obtained in moderate to excellent yields (15-97 %). Cyclic voltammetry experiments reveal that the solvent plays a crucial role in this transformation and this reaction involves two consecutive single-electron transfer events.

Cyclohexylidene-based amines exhibit unique axial chirality arising from the restricted double bond and have shown great potential in medicinal chemistry. However, their asymmetric synthesis remains challenging due to the long distance between the chirally relevant groups. Herein, we report a highly efficient and asymmetric synthesis of cyclohexylidene-based axially chiral amines from 4-substituted cyclohexanones and primary amines catalyzed by imine reductases (IREDs). Enantiodivergent IREDs were identified to provide convenient access to both enantiomers of chiral products with high yields and enantioselectivity (up to 99% yield, 99:1 or 1:99 enantiomeric ratio). A gram-scale synthesis of cyclohexylidene-based amines was also achieved. Moreover, protein X-ray crystallography and molecular modeling studies were conducted to provide structural insight into the remote stereocontrol of IREDs in generating cyclohexylidene-based axial chirality.

We present a ligand-to-metal charge transfer (LMCT)-enabled catalytic platform utilizing cerium(IV) benzoate complexes to address the long-standing challenge of directly coupling free alcohols with electron-rich alkenes, overcoming inherent polarity mismatches. This approach effectively circumvents the typical selectivity in single-electron transfer processes, enabling the selective generation of electrophilic alkoxy radicals from free alcohols in the presence of redox-labile electron-rich alkenes. The Ce-benzoate-based photocatalytic protocol promotes regioselective hydroetherification via both intramolecular cyclization and intermolecular addition pathways, showcasing broad functional group tolerance, operational simplicity, and versatility across a diverse array of alkenes, including silyl enol ethers and enamides/enecarbamates. Detailed mechanistic studies elucidate the structure of the active Ce(IV) benzoate catalyst, highlighting its unique selectivity for alkoxy radical generation, thereby establishing a practical and atom-economical framework for hydroetherification.

The development of new methods for aromatic ring-expansion offers a strategic means of transforming abundant aromatic feedstocks into intricate structures via skeletal editing, thereby unlocking valuable avenues for organic synthesis. We report herein a mild and efficient ruthenium-catalyzed ring-expansion of 2-silylfurans to form 1,2-oxasilines with wide substrate scope and excellent functional group tolerance. Density functional theory (DFT) calculations suggest the reaction proceeds through regioselective insertion of furan double bond into a Ru & horbar;H bond, followed by skeletal rearrangement, 1,2-hydride transfer, and elimination steps. The resulting 1,2-oxasilines are electron-rich cyclic dienes with an extrudable and transformable Si & horbar;O linker, which exhibit unique and versatile reactivity in Diels-Alder cyclization with electron-deficient dienophiles, enabling modular assembly of molecular skeletons with higher complexity.