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After simply filtering and evaporating, the recovery rates of compound 1 and mineral oil are 81% and 93%, respectively.

Rigidly planar polycyclic phosphacycles featuring an internal dioxaphosphorane are promising photofunctional materials. However, the lack of efficient synthetic methods resulted in limited structural diversities which significantly hampered extensive study. Herein, we report a straightforward three-component synthesis of novel dioxaphosphorane-fused diphosphacycles with distinctive photophysical properties. Control experiments and theory calculations were performed to account for a plausible reaction mechanism. We also systematically investigated the structure-property relationships of these unprecedented platforms by combining experiments (X-ray analysis, optical and redox properties) and theoretical computations. Based on their unique structure and properties, a novel fluorescent switch for pH sensing was revealed by a dynamic ring-opening/ring-closing process.

The wavelength-regulated, methylene blue organic dye catalyzed stereodivergent synthesis of (Z)- and (E)-1,4-enediones from stabilized phosphorous ylides is reported. Broad ranges of substrates and functional groups are tolerated. Mechanistic studies suggested singlet-oxygen-promoted (E)-alkene formation via a possible phospha-1,2-dioxetane intermediate, followed by a blue-LED triggered (E) → (Z) isomerization reaction.

Semifluoroalkyl triazole derivatives have been facilely synthesized by copper-catalyzed alkyne-azide cycloaddition reaction, which can gelate some organic solvents at weight concentrations of down to 0.5 wt.%. The gelation abilities of triazole derivatives with/without a semifluoroalkyl and an aromatic group were fully characterized. We found that triazole derivatives containing semifluoroalkyl chains and aromatic groups are typically effective in forming supramolecular organogels. Moreover, the gelator in ethyl acetate can solidify oil from an oil-water biphasic mixture for about 1 min.

Effective screening of infectious diseases requires a fast, cheap, and population-scale testing. Antigen pool testing can increase the test rate and shorten the screening time, thus being a valuable approach for epidemic prevention and control. However, the overall percent agreement (OPA) with polymerase chain reaction (PCR) is one-half to three-quarters, hampering it from being a comprehensive method, especially pool testing, beyond the gold-standard PCR. Here, a multiantibodies transistor assay is developed for sensitive and highly precise antigen pool testing. The multiantibodies capture SARS-CoV-2 spike S1 proteins with different configurations, resulting in an antigen-binding affinity down to 0.34 fM. The limit of detection reaches 3.5 × 10-17 g mL-1SARS-CoV-2 spike S1 protein in artificial saliva, 4-5 orders of magnitude lower than existing transistor sensors. The testing of 60 nasopharyngeal swabs exhibits ∼100% OPA with PCR within an average diagnoses time of 38.9 s. Owing to its highly precise feature, a portable integrated platform is fabricated, which achieves 10-in-1 pooled screening for high testing throughput. This work solves the long-standing problem of antigen pool testing, enabling it to be a valuable tool in precise diagnoses and population-wide screening of COVID-19 or other epidemics in the future.

A series of carbohydrate-conjugated 4-methylumbelliferone were synthesized using 1,3-dipolar cycloaddition “click chemistry” of the azide and alkyne. The reaction is straight forward and in high yield. The strategy will be useful for synthesizing glycoconjugated derivatives of natural products.

A naturally occurring nucleoside disulfide, 9-(5′-deoxy-5′-thio-β-d-xylofuranosyl)adenine disulfide, was first synthesized from d-xylose over 7 steps in 20% overall yield. The key step involved Vorbruggen glycosylation of silylated N6-benzoyladenine with xylose diacetate moiety.