Methylation is one of the most fundamental synthetic transformationsi no rganic chemistry, but usually employs hazardous and toxicr eagents, such as methyl iodide,d imethyls ulfate,d iazomethane and dimethylc arbonate.I no rder to address sustainable development and green strategies,s ynthetic chemists have devoted much effort to the discovery and development of new methylating reagents,w hich are successfully beinga pplied in transition metal-catalyzed cross-coupling reactions.I nt his review,r ecent advances in this area are summarized, mainly including C-methylation, N-methylation and O-methylation.T he respective reaction mechanisms are also discussed. 1I ntroduction 2C -Methylation 2.1 Methylation of Aryl and Vinyl (Pseudo)Halides 2.2 Methylation of C À HB onds 2.3 Decarboxylative Methylation of a,b-Unsaturated Acids 2.4 Others 3N -Methylation of N-Containing Compounds 4O -MethylationofC arboxylic Acids 5C onclusions and Perspectives

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Different mulches have variable effects on soil physical properties and plant growth. This study aimed to compare the effects of mulching with inorganic (round gravel, RG), organic (wood chips, WC), and living (manila turf grass, MG) materials on soil properties at 0–5-cm and 5–10-cm depths, as well as on the growth and physiological features of Osmanthus fragrans L. ‘Rixianggui’ plants. Soil samples were collected at three different time points from field plots of O. fragrans plants treated with the different mulching treatments. Moisture at both soil depths was significantly higher after mulching with RG and WC than that in the unmulched control (CK) treatment. Mulching did not affect soil bulk density, pH, or total nitrogen content, but consistently improved soil organic matter. The available nitrogen in the soil increased after RG and WC treatments, but decreased after MG treatment during the experimental period. Mulching improved plant growth by increasing root activity, soluble sugar, and chlorophyll a content, as well as by providing suitable moisture conditions and nutrients in the root zone. Plant height and trunk diameter were remarkably increased after mulching, especially with RG and WC. However, while MG improved plant growth at the beginning of the treatment, the ‘Rixianggui’ plants later showed no improvement in growth. This was probably because MG competed with the plants for water and available nitrogen in the soil. Thus, our findings suggest that RG and WC, but not MG, improved the soil environment and the growth of ‘Rixianggui’ plants. Considering the effect of mulching on soil properties and plant growth and physiology, round gravel and wood chips appear to be a better choice than manila turf grass in ‘Rixianggui’ nurseries. Further studies are required to determine the effects of mulch quality and mulch-layer thickness on shoot and root growths.

Development of methodology for the preparation of nitroolefins is of significant interest to organic chemists. Recently, numerous useful methods have been developed, mainly including direct nitration of olefinic C-H bonds, nitro-decarboxylation of aromatic α,β-unsaturated carboxylic acids, ipso-nitration of vinylboronic acids and multidehydrogenative cross-coupling reaction of (hetero)arenes with nitroethane. This review will focus on recent achievements in nitroolefin synthesis and the mechanisms of the reactions are also discussed.

WRKY transcription factors, one of the largest transcription factor families, play important roles in regulating the synthesis of secondary metabolites. In sweet osmanthus (Osmanthus fragrans), the monoterpenes have been demonstrated as the most important volatile compounds, and the W-box, which is the cognate binding site of WRKY transcription factors, could be identified in most of the terpene-synthesis-related genes’ promoters. However, the role of the WRKY family in terpene synthesis in sweet osmanthus has rarely been examined. In this study, 154 WRKY genes with conserved WRKY domain were identified and classified into three groups. The group II was further divided into five subgroups, and almost all members of IId contained a plant zinc cluster domain. Eight OfWRKYs (OfWRKY7/19/36/38/42/84/95/139) were screened from 20 OfWRKYs for their flower-specific expression patterns in different tissues. Simultaneously, the expression patterns of OfWRKYs and emission patterns of volatile compounds during the flowering process were determined and gas chromatography-mass spectrometry results showed that monoterpenes, such as linalool and ocimene, accounted for the highest proportion, contributing to the floral scent of sweet osmanthus in two cultivars. In addition, correlation analysis revealed the expression patterns of OfWRKYs (OfWRKY7/19/36/139) were each correlated with distinct monoterpenes (linalool, linalool derivatives, ocimene and ocimene derivatives). Subcellular localization analysis showed that p35S::GFP–OfWRKY7/38/95/139 were localized in the nucleus and OfWRKY139 had very strong transactivation activity. Collectively, the results indicated potential roles of OfWRKY139 and OfWRKYs with plant zinc cluster domain in regulating synthesis of aromatic compounds in sweet osmanthus, laying the foundation for use of OfWRKYs to improve the aroma of ornamental plants.