Base-Mediated Chemodivergent [4 + 1] and [2 + 1] Cycloadditions of -Alkylpyridiniums and Enones.

Divergent synthesis of structurally different products from the same kinds of starting materials is highly synthetically useful but very challenging. Herein, we reported a base-mediated chemodivergent [4 + 1] and [2 + 1] cycloaddition of -alkylpyridinium and enone under mild conditions, leading to furan-fused bicycles with high diastereoselectivity and spirobicycles, respectively, from moderate to high yields. -Alkylpyridinium salts were modular nucleophilic transfer reagents and C1 synthons, which underwent tandem Michael addition to the α,β-unsaturated ketones and cyclization under the base conditions.

A Comprehensive Review of Natural Flavonoids with Anti-SARS-CoV-2 Activity.

The COVID-19 pandemic caused by SARS-CoV-2 has majorly impacted public health and economies worldwide. Although several effective vaccines and drugs are now used to prevent and treat COVID-19, natural products, especially flavonoids, showed great therapeutic potential early in the pandemic and thus attracted particular attention. Quercetin, baicalein, baicalin, EGCG (epigallocatechin gallate), and luteolin are among the most studied flavonoids in this field.

A D-cysteine desulfhydrase, SlDCD2, participates in tomato fruit ripening by modulating ROS homoeostasis and ethylene biosynthesis.

Hydrogen sulfide (HS) is involved in multiple processes during plant growth and development. D-cysteine desulfhydrase (DCD) can produce HS with D-cysteine as the substrate; however, the potential developmental roles of DCD have not been explored during the tomato lifecycle. In the present study, showed increasing expression during fruit ripening.

Asymmetric Construction of an Aryl-Alkene Axis by Palladium-Catalyzed Suzuki-Miyaura Coupling Reaction.

The application of Suzuki-Miyaura coupling reaction to forge the atropisomeric biaryls has seen remarkable progress but exploration of this chemistry to directly forge chiral C(aryl)-C(alkene) axis is underdeveloped. The replacement of arene substrates by alkenes intensifies the challenges in terms of reactivity, configurational atropostability of product and selectivity control. By meticulous ligand design and fine-tuning of reaction parameters, we identified a highly active 3,3'-triphenylsilyl-substituted phosphite ligand to realize arene-alkene Suzuki-Miyaura coupling of hindered aryl halides and vinyl boronates under very mild conditions.