Herein, the first acceptorless dehydrogenation of tetrahydroquinolines (THQs), indolines, and other related N-heterocycles, by merging visible-light photoredox catalysis and cobalt catalysis at ambient temperature, is described. The potential applications to organic transformations and hydrogen-storage materials are demonstrated. Primary mechanistic investigations indicate that the catalytic cycle occurs predominantly by an oxidative quenching pathway.

Cleavage of C–O bonds in lignin can afford the renewable aryl sources for fine chemicals. However, the high bond energies of these C–O bonds, especially the 4-O-5-type diaryl ether C–O bonds (~314 kJ/mol) make the cleavage very challenging. Here, we report visible-light photoredox-catalyzed C–O bond cleavage of diaryl ethers by an acidolysis with an aryl carboxylic acid and a following one-pot hydrolysis. Two molecules of phenols are obtained from one molecule of diaryl ether at room temperature. The aryl carboxylic acid used for the acidolysis can be recovered. The key to success of the acidolysis is merging visible-light photoredox catalysis using an acridinium photocatalyst and Lewis acid catalysis using Cu(TMHD)2. Preliminary mechanistic studies indicate that the catalytic cycle occurs via a rare selective electrophilic attack of the generated aryl carboxylic radical on the electron-rich aryl ring of the diphenyl ether. This transformation is applied to a gram-scale reaction and the model of 4-O-5 lignin linkages.

Herein, the first acceptorless dehydrogenation of tetrahydroquinolines (THQs), indolines,a nd other related Nheterocycles,bymerging visible-light photoredox catalysis and cobalt catalysis at ambient temperature,i sd escribed. The potential applications to organic transformations and hydrogen-storage materials are demonstrated. Primary mechanistic investigations indicate that the catalytic cycle occurs predominantly by an oxidative quenchingpathway. Scheme 1. Strategies for acceptorless dehydrogenation of THQs. Scheme 2. Possible pathway for dehydrogenation of THQs.

Comprehensive Summary We develop an efficient visible‐light photoreodox‐catalyzed hydrodecarboxylation and deuterodecarboxylation of fatty acids for alkanes and deuterium alkanes. The key to the efficient transformation should attribute to the co‐catalysis of the suitable methoxy substituted acridine photocatalyst (Mes‐1,3,6,8‐tetramethoxy‐Acr‐3”,5”‐dimethoxy‐Ph) and the hydrogen atom transfer catalyst 4′,4′‐dimethyl diphenyldisulfane, possibly via facilitating of quenching the active alkyl radicals to overcome the competitive homocoupling products, olefins via the disproportionation, cracking products via the C—C bond β‐scission.

The synthesis of Yanglingmycin and its enantiomer, along with eighteen Yanglingmycin analogues is reported. The structures were confirmed mainly by analyses of NMR spectral data. Antibacterial activity assays showed that Yanglingmycin and some of its analogues exhibited significant antibacterial activities against two important agricultural pathogenic bacteria, Ralstonia solanacearum and Pseudomonas syringae pv. actinidiae, with minimum inhibitory concentration (MIC) values ranging from 3.91 to 15.62 µg/mL. The antibacterial activities exhibited by Yanglingmycin and its analogues are promising, suggesting potential in the development of compounds for novel bactericides.Key words Yanglingmycin; structural analogue; substituted cyclic azole; antibacterial activity Bacterial diseases pose a major threat to agricultural production worldwide. For example, Ralstonia solanacearum, which causes plant bacterial wilt, is one of the most destructive plant pathogens, and affects many regions of the world. 1)It is estimated that R. solanacearum is responsible for US$ 1 billion in losses each year.2) Pseudomonas syringae pv. actinidiae, which causes kiwifruit canker, is another devastating plant pathogen and has received significant attention in recent years.3-6) Thus, there has been considerable interest in development of bactericides for Ralstonia solanacearum and Pseudomonas syringae pv. actinidiae. Unfortunately, there have been few reports of effective bactericides against these pathogens. In the process of screening new agricultural antibiotics, we report the synthesis a new broad spectrum antibiotic, Yanglingmycin (Fig. 1), which was found to be effective against the previously mentioned pathogens. 7) Although Yanglingmycin can be isolated from the fermentation broth of Streptomyces djakartensis, the yield is too low to conduct experiments to determine the mechanism of bactericidal action. In order to investigate the bactericidal activities of Yanglingmycin and its analogues, Yanglingmycin and its analogues were designed and synthesized. In this paper, Yanglingmycin and its enantiomer and eighteen Yanglingmycin analogues were synthesized and their antibacterial activities against Ralstonia solanacearum and Pseudomonas syringae pv. actinidiae are reported. ResultsChemistry Chart 1 describes the synthesis of all target compounds. Benzonitrile, 2-hydroxybenzonitrile, and 4-hydroxybenzonitrile were used as starting material for the Pinner reaction to obtain the corresponding methyl benzimidate hydrochlorides, 8) which were then reacted with each the following compounds: L-serine methyl ester hydrochloride, D-serine methyl ester hydrochloride, L-cysteine methyl ester hydrochloride, D-cysteine methyl ester hydrochloride, L-2,3-diaminopropionic acid methyl ester hydrochloride, and D-2,3-diaminopropionic acid methyl ester hydrochloride.9,10) Amino acid methyl ester hydrochlorides were obtained by reacting the corresponding amino acids with AcCl in MeOH.11) The products were reduced by LiAlH 4 to obtain Yanglingmycin and its an...