The green fraction of humic acids (HAS), Pg, was fractionated by gel chromatography on Sephadex G-50. Repeated chromatography of the crude Pg obtained by the first chromatography of HA yielded a sharp peak (G1) and two broad bands (G2) of purified Pg. The recovery of Pg in G1 and G2 as percentages of the total Pg content of the HA were 16.2 and 14.5%, respectively. Distinct peaks were detected at 615, 570,450 and 280 nm in the UV-visible spectra of both G1 and G2 in alkali solutions. Estimates of weight-average molecular weight were 9.7 x lo3 for GI and 1.23 x lo4 for G 2 . In the IH-NMR spectra the percentage of hydroxyl groups of 4,9-dihydroxyperylene-3,lO-quinone (DHPQ) nuclei, which are known to be the chromophore of Pg, was 4.1 and 4.5% of the total H, respectively. Based on these values and the WC ratios, DHPQ-C was estimated as 28% of total C. 13C-NMR spectra obtained using inverse-gated decoupling yielded 40-41 % aromatic C, which suggested the presence of aromatic rings other than DHPQ. All of the IR, I3C-and 'H-NMR spectra indicated that the two purified Pg samples largely differed from each other in their contents of alkyl and polysaccharide components.

Intermediary radical cations, generated through single-electron oxidation of enol silyl ethers by excited Irbased photocatalysts, can be exploited as Brønsted acids for the activation of heteroarylcyanides. This strategy enables the direct allylic CÀ H heteroarylation of enol silyl ethers under visible-light irradiation.

Thioamidate ions are introduced as competent cocatalysts for multisite proton-coupled electron transfer (MS-PCET) catalysis. The effectiveness of these anions is ascribed to the high pKa values of their conjugate acids. The combined use of bench-stable tetrabutylammonium thioamidate with an appropriate Ir-based photosensitizer allows the C–H alkylation of a range of C–H donors, including simple cyclic alkanes, under visible-light irradiation.

The reaction pathways of transient radical species are difficult to control, like the soap bubbles in the wind depicted in the cover image. Yet, these short‐lived intermediates, when one encounters another, readily assemble into a united structure, as two bubbles fuse into a bigger single bubble. The enol silyl ether‐derived radical cations with a highly acidic allylic proton facilitates the single‐electron reduction of cyanopyridines via protonation. The resulting two radical intermediates successively engage in the radical−radical coupling to produce heteroarylated enol silyl ethers. More information can be found in the Communication by T. Ooi et al. (DOI: 10.1002/chem.202101352).