Ti(OiPr)4-Facilitated Formal Deoxygenative Annulation of Alkynyl 1,2-Diketones for the Synthesis of Highly Functionalized Furans

Discovery of novel sulfonamide derivatives containing pinacolone moieties as fungicide candidates against Botrytis cinerea

BACKGROUND

Botrytis cinerea is one of the most serious plant diseases and severely threatens agricultural production. The rapidly intensifying resistance makes most commercial chemical fungicides lose control efficacy. Developing new fungicides with novel structures and modes of action is an effective measure to solve this problem.

RESULTS

In this work, 29 novel sulfonamide compounds containing pinacolone scaffolds were designed and synthesized based on the active substructure splicing strategy. The biological activity assay on three kinds of Botrytis cinerea strains manifested that these compounds exhibit moderate to excellent antifungal activity. Compounds 3a-1 and 3a-11 displayed the highest in vitro antifungal activity similar to control agents carbendazim, procymidone, and boscalid. Compound 3c had the lowest EC50 value of 1.96 μg/mL against strain PJ-02 compared to boscalid (6.90 μg/mL). Bioassay results on strawberry fruits and tomato pots indicated that compounds 3a-1 and 3a-11 also possess superb in vivo antifungal activity compared to control agents. The electronic conductivity measurement results showed that compound 3a-1 can significantly increase the membrane permeability of Botrytis cinerea mycelium. Scanning electron microscopy observation revealed that compound 3a-1 could cause the Botrytis cinerea mycelium to twist and break, and inhibit mycelium branching. Density functional theory calculation and molecular electrostatic potential distribution were also used to analyze the activity mechanism of target compounds.

CONCLUSION

Due to their excellent antifungal activity against Botrytis cinerea, these novel sulfonamide derivatives containing pinacolone scaffolds could be considered qualified fungicide candidates. Preliminary exploration of the mechanism suggests that this kind of compound may possess a novel mode of action. © 2025 Society of Chemical Industry.

Titanium in photocatalytic organic transformations: current applications and future developments

Titanium, as an important transition metal, has garnered extensive attention in both industry and academia due to its excellent mechanical properties, corrosion resistance, and unique reactivity in organic synthesis. In the field of organic photocatalysis, titanium-based compounds such as titanium dioxide (TiO2), titanocenes (Cp2TiCl2, CpTiCl3), titanium tetrachloride (TiCl4), tetrakis(isopropoxy)titanium (Ti(OiPr)4), and chiral titanium complexes have demonstrated distinct reactivity and selectivity. This review focuses on the roles of these titanium compounds in photocatalytic organic reactions, and highlights the reaction pathways such as photo-induced single-electron transfer (SET) and ligand-to-metal charge transfer (LMCT). By systematically surveying the latest advancements in titanium-involved organic photocatalysis, this review aims to provide references for further research and technological innovation within this fast-developing field.

Towards tetrasubstituted furans through rearrangement and cyclodimerization of acetylenic ketones

Cyclodimerization of readily accessible acetylenic ketones facilitated by a phosphane-borane complex under basic conditions is achieved. This methodology allows one-pot synthesis of phosphorus-involved tetrasubstituted furans via the construction of a C-P bond and a furan ring within a single procedure. A plausible reaction mechanism is proposed.

Titanium-Mediated Domino Cross-Coupling/Cyclodehydration and Aldol-Addition/Cyclocondensation: Concise and Regioselective Synthesis of Polysubstituted and Fused Furans

Titanium enolates, in situ-generated from readily available ketones and titanium tetraisopropoxide, undergo domino cross-coupling/cyclodehydration or domino Aldol-addition/cyclocondensation with α-chloroketones to provide synthetically valuable furan derivatives. The domino process tolerates a variety of cyclic and acyclic ketones and chloroketones, producing polysubstituted furans and bi-, tri-, and tetracyclic fused furans.