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The first example for the ruthenium-catalyzed ligand-directed meta-selective C-H mono- and difluoromethylation is developed, affording a variety of new meta-mono- and difluoromethylated 2-phenylpyridines, 2-phenylpyrimidines, and 1-phenylpyrazoles in moderate-to-good yields. This new transformation exhibits broad substrate scope, good functional group tolerance, and high efficiency, and offers a practical approach to synthesize mono- and difluoromethylated arenes. Mechanistic studies indicate that a reaction pathway involving palladium-initiated radical species is involved in the catalytic cycle. The new dual catalytic system consisting of compatible ruthenium(II) and palladium(0) complexes enables the key processes of C-H activation and mono-/difluoromethyl-radical formation to occur and achieves the meta-selective functionalization efficiently. In addition, the present protocol can also be extended to non-fluoromethylation.

Mango (Mangifera indica) is widely grown across southern China, especially in the provinces of Guangxi, Hainan, Yunnan, Sichuan, and Taiwan. Guangxi itself has over 86,667 ha of mango production. The purpose of this study was to identify Colletotrichum species associated with mango in different parts of Guangxi and examine their pathogenicity on leaves and fruits of mango in vitro. Diseased leaves were collected from 25 mango orchards in different areas of Guangxi province. Sixty-five isolates were obtained from mango leaves with anthracnose symptoms, and these were further characterized based on morphology and DNA sequencing. Twenty-nine isolates from different areas were selected for sequencing and analyses of the internal transcribed spacer region, glyceraldehyde-3-phosphate dehydrogenase, partial actin, β-tubulin, and chitin synthase genomic regions. The most common fungal isolates were these three species: Colletotrichum asianum, C. fructicola, and C. siamense. C. asianum was the most common and widely distributed in Guangxi (51.7%), followed by C. fructicola (37.9%) and C. siamense (10.2%), both found in Tiandong, Tianyang, and Wuming counties. There was no evidence of geographical specialization of the different species. Pathogenicity assays showed that all isolates were pathogenic to mango leaves and fruit (cultivar Tainong). No relationship was found between origin of isolates and their virulence. This is the first description of C. asianum, C. fructicola, and C. siamense as causal agents of mango leaf anthracnose from Guangxi province, China.

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A palladium-catalyzed decarboxylative ortho-acylation of tertiary benzamides with α-oxocarboxylic acids by weak O-coordination has been described. This reaction proceeds smoothly with a high monoacylation selectivity, affording ortho-acylated benzamides in moderate to good yields. When secondary benzamides are employed as the substrates, the formed ortho-acylated benzamides undergo further intramolecular cyclization to provide isoindolinone derivatives. In addition, several transformations of the synthesized ortho-acylated benzamides into a diversity of synthetically valuable products have been demonstrated.

Mango (Mangifera indica L.) is an economically significant fruit crop in provinces of southern China including Hainan, Yunnan, Sichuan, Guizhou, Guangdong and Fujian. The objective of this study was to examine the diversity of Colletotrichum species infecting mango cultivars in major growing areas in China, using morphological and molecular techniques together with pathogenicity tests on detached leaves and fruits. Over 200 Colletotrichum isolates were obtained across all mango orchards investigated, and 128 of them were selected for sequencing and analyses of actin (ACT), chitin synthase (CHS-1), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), the internal transcribed spacer (ITS) region, β-tubulin (TUB2) genomic regions. Our results showed that the most common fungal isolates associated with mango in southern China involved 13 species: Colletotrichum asianum, C. cliviicola, C. cordylinicola, C. endophytica, C. fructicola, C. gigasporum, C. gloeosporioides, C. karstii, C. liaoningense, C. musae, C. scovillei, C. siamense and C. tropicale. The dominant species were C. asianum and C. siamense each accounting for 30%, and C. fructicola for 25%. Only C. asianum, C. fructicola, C. scovillei and C. siamense have previously been reported on mango, while the other nine Colletotrichum species listed above were first reports associated with mango in China. From this study, five Colletotrichum species, namely C. cordylinicola, C. endophytica, C. gigasporum, C. liaoningense and C. musae were the first report on mango worldwide. Pathogenicity tests revealed that all 13 species caused symptoms on artificially wounded mango fruit and leaves (cv. Tainong). There was no obvious relationship between aggressiveness and the geographic origin of the isolates. These findings will help in mango disease management and future disease resistance breeding.