Identification of O-arylated huperzinines as novel cholinergic anti-inflammatory pathway agonists against gout arthritis.

Lycodine alkaloids are important natural products with diverse biological effects. In this manuscript, we set out the first structural optimization of the 2-pyridone moiety of Lycodine alkaloid via selective O-arylation under metal-free conditions and obtained a series of potent bioactive molecules against monosodium urate (MSU)-induced IL-1ß production. Further investigations demonstrated that these natural product derivatives could activate the neuro-immunomodulatory cholinergic anti-inflammatory pathway (CAP) to block the initial phase of NLRP3 inflammasome activation. Compared with the clinical drugs hydrocortisone and indomethacin, as well as commercially available CAP agonists GTS-21 and pnu282987, 3k and 3q possessed greater potency against MSU-induced IL-1ß production. Meanwhile, these molecules possessed less cytotoxicity against promonocytic THP-1 macrophages when compared with colchicine. This work reports a concise strategy for direct modification of 2-pyridone moiety from natural Lycodine alkaloids, and provides novel frameworks for discovering CAP activators and drugs for gout arthritis.

Synthesis of Indole-Fused Pyrazino[1,2-a]quinazolinones by Copper(I)-Catalyzed Selective Hydroamination-Cyclization of Alkynyl-tethered Quinazolinones.

We described a copper(I)-catalyzed atom economic and selective hydroamination-cyclization of alkynyl-tethered quinazolinones to prepare a variety of indole-fused pyrazino[1,2-a]quinazolinones in good to excellent yields ranging from 39 %-99 % under mild reaction conditions. Control experiments revealed that coordination-directed method of quinazolinone moiety with copper(I) was important for the selective hydroamination-cyclization of alkynes at the N1-atom instead of N3-atom of quinazolinone. The reaction could be easily performed at gram scales and some prepared indole-fused pyrazino[1,2-a]quinazolinones with donating groups on the indole moiety showed a distinct fluorescence emission wavelength with blue shift under the acid conditions.

Recent advances in the synthesis of 2,3-fused quinazolinones.

As one of the most important structural units in pharmaceuticals and medicinal chemistry, quinazolinone and its derivatives exhibit a wide range of biological and pharmacological activities, including anti-inflammatory, antitubercular, antiviral, and anticancer activities, etc. In particular, 2,3-fused quinazolinones have attracted much attention because the rings fused to the 2,3-positions of quinazolinones improve their rigidity and planarity. Their synthetic strategies have made great advances in recent years. Therefore, this review focuses on novel strategies for the synthesis of 2,3-fused quinazolinone derivatives from 2017 to 2022, such as the difunctionalization of alkenes, the ring-opening of easily available small rings, dehydrogenative cross-coupling reactions, transition-metal catalyzed cyclizations, cycloadditions, and other cascade reactions.

Synthesis of spiroindolenine-3,3'-pyrrolo[2,1-b]quinazolinones through gold(I)-catalyzed dearomative cyclization of N-alkynyl quinazolinone-tethered indoles.

A variety of functionalized spiroindolenine-3,3'-pyrrolo[2,1-b]quinazolinones were prepared in good to excellent yields through a gold(I)-catalyzed dearomative cyclization of N-alkynyl quinazolinone-tethered C2-substituted indoles. This reaction features a broad substrate scope, good functional group tolerance, and easy gram-scale preparation and transformations. Furthermore, biological activity studies showed that most of the obtained spiroindolenine-3,3'-pyrrolo[2,1-b]quinazolinone scaffolds showed potential as good anti-inflammatory agents.

Palladacycle-Catalyzed Regioselective Heck Reaction Using Diaryliodonium Triflates and Aryl Iodides.

We describe a P-containing palladacycle-catalyzed regioselective Heck reaction of 2,3-dihydrofuran with diaryliodonium salts and aryl iodides to afford 2-aryl-2,5-dihydrofurans and 2-aryl-2,3-dihydrofurans, respectively, in good yields. Mechanistic studies revealed that the oxidative addition of diaryliodonium salts to palladacycles to form Pd(IV) species showed high chemoselectivity and that electron-rich aryl moieties were preferentially transferred to the Heck product. DFT calculations indicated that the regioselectivity-determining step is the reductive elimination reaction rather than the isomerization and reinsertion of Pd(IV)-hydride intermediates into the double bond.