Yuting Leng

A visible light–induced cascade cyclization strategy of unactivated alkenes with N ‐aminopyridinium salts was explored to build a series of tetrahydropyridazines and dihydropyrazoles in yield of 17% –82% with 41 examples. This protocol features mild reaction conditions (irradiation with a 10 W blue LED at room temperature) and can simultaneously form two chemical bonds, offering a rapid and concise approach to five‐ or six‐membered heterocyclic frameworks. The scalability of this method and the feasibility of further transformations have also been demonstrated, highlighting its potential for applications in the industrial and pharmaceutical sectors.

Thermal [3+2] cyclization in aqueous media for the synthesis of thieno/selenopheno[2,3- b ]quinoline derivatives.

A photoredox-catalyzed strategy enables the dual N-centered radical cascade cyclization of N-cyanamide olefins with N-sulfon/benzoylaminopyridinium salts, efficiently constructing 48 amide-decorated 2,3-fused polycyclic quinazolinones in yields of up to 86%. This metal- and base-free protocol exhibits mild reaction conditions. Moreover, they are compatible with a variety of functional groups and can accommodate a range of substrate structures. Notably, the method's practical utility is highlighted by successful gram-scale implementation and facile downstream derivatization.

A photocatalytic three-component cyclization reaction of 2-vinylarylamines with CF₃SO₂Na and arylaldehydes to access 3-(2,2,2-trifluoroethyl)-3H-indoles was developed.

A visible-light-initiated deaminative alkylation/cyclization of isocyanophenylquinazolinones with Katritzky salts for the synthesis of polycyclic quinazolinone derivatives has been developed. This protocol features a broad substrate scope with 49 examples and efficient reaction conditions without additional catalysts and oxidants, which provides rapid access to pharmaceutically valuable analogues containing quinazolinone-fused compounds with yields up to 98% under 15 W blue LED irradiation for 0.5-3 h. The large-scale reaction of this method and the further transformations to useful polycyclic quinazolinones also afford positive results. Mechanism studies indicate that the formation of EDA complexes between Katritzky salts and DABCO initiates the reaction process.

In this report, an efficient copper-catalyzed radical cascade cyclization of aryl aldehyde-derived hydrazones with a Togni reagent or AgSCF₃ in two directions to access a series of trifluoromethylated five/six/seven-membered heterocycles and trifluoromethylthiolated five-membered heterocycles was developed. The model reaction was extrapolated with 74 examples, affording satisfactory yields for desired products. Further transformation and large-scale experiments were conducted and gave positive results, which paved the way to a broad application of the protocol. Additionally, the same cascade reaction of trifluoromethylation can also be realized through a photochemical approach using 4CzIPN as an organic photocatalyst at room temperature, which might provide a more mild method for constructing valuable heterocycles with biological potential.

This article reports a synthesis of hydroxyacylation substituted pyrrolidinone derivatives through regioselective tandem cyclization reaction of 1,5-dienes with phenylglyoxylic acid and water under visible light irradiation. This protocol features mild reaction conditions using a 12 W blue LED as the light source and CH₃CN/H₂O (1 : 1) as the solvent at room temperature. Additionally, a range of pyrrolidinones bearing two chiral centers can be easily accessed by this strategy, with the yields up to 78%, which makes the protocol more appealing toward natural product and medicinal chemistry development.

A visible-light-induced radical cyclization of α-brominated amides has been developed to construct benzimidazole[2,1-a]isoquinolin-6(5H)-ones and pyrrolidonesin in yields up to 97%. The methodology exhibits a certain functional-group compatibility with 43 examples and operational simplicity, offering a rapid and concise approach to obtain five- and six-membered rings under the irradiation of 18 W blue LED. Additionally, large-scale reaction of this method for synthesizing benzimidazo-isoquinolineones and the further transformations to useful pyrrolidones were also conducted and afforded positive results.

A new environmentally friendly and efficient strategy for preparing trifluoromethylated pyrrolidones has been developed. The process involves using visible light to induce radical cyclization of 1,5‐dienes with CF₃SO₂Na, resulting in excellent regioselectivity. This method uses less expensive and easy‐to‐store trifluoromethylation reagents, making it an attractive option. Additionally, the resulting trifluoromethylated pyrrolidones can be easily modified and preliminary mechanistic studies have been presented.

A visible‐light‐mediated synthesis of 3‐alkyl‐ substituted chroman‐4‐one derivatives via deaminative alkylation of amino acid derived Katritzky salts and tandem cyclization with o‐(allyloxy)arylaldehydes has been developed. This approach exhibits functional‐group compatibility with 31 examples and affords the desired products in yields of 16–88%. Mechanistic research results suggest that the formation of EDA complexes between the Katritzky salts and a base is the main reason for initiating the reaction.