Silver-Catalyzed Radical Aminofluorination of Unactivated Alkenes in Aqueous Media

We report herein a mild and catalytic intramolecular aminofluorination of unactivated alkenes. Thus, with the catalysis of AgNO₃, the reactions of various <i>N</i>-arylpent-4-enamides with Selectfluor reagent in CH₂Cl₂/H₂O led to the efficient synthesis of 5-fluoromethyl-substituted γ-lactams. A mechanism involving silver-catalyzed oxidative generation of amidyl radicals and silver-assisted fluorine atom transfer was proposed

Stereoselectivity of 6-<i>Exo</i> Cyclization of α‑Carbamoyl Radicals

The stereoselectivity in the 6-<i>exo</i> cyclization of α-carbamoyl radicals was investigated experimentally and theoretically. The BEt₃/O₂-initiated iodine-atom-transfer radical cyclization reactions of substituted <i>N</i>-(but-3-en-1-yl)-<i>N</i>-(<i>tert</i>-butyl)-2-iodoalkanamides were carried out, which led to the predominant formations of 3,4-<i>cis</i>, 4,5-<i>trans</i>, or 4,6-<i>trans</i> substituted δ-lactams. Density functional calculations at the B3LYP/6-31G* level revealed that the 6-<i>exo</i> radical cyclization proceeds via boat-conformational transition states. Furthermore, a mechanistic insight into the stereoselectivity was provided and the calculation results were in excellent agreement with the experimental observations

Election Procedure for Rural Two Committees

In order to further strengthen the construction and improvement of villager autonomy system with democratic election, democratic decision making, democratic management, and democratic supervision of rural two committees with Chinese characteristics, experience of work team of Longyang District Agricultural Technology Extension Station dispatched to villager committees (or offices) and their guidance on election of rural two committees in 2007-2016 were used, and exploration was made for election of rural two committees from the third to the sixth committees. It summarized achievements and main problems in election of rural two committees and came up with pertinent recommendations. The results of this study are expected to provide certain reference for theory and practice of future villager autonomy

Identification of a Novel Walnut Iron Chelating Peptide with Potential High Antioxidant Activity and Analysis of Its Possible Binding Sites

Peptide iron chelate is widely regarded as one of the best iron supplements for relieving iron deficiency. In this study, a new type of walnut peptide iron (WP-Fe) chelate was prepared using low molecular weight walnut peptides (WP) as raw materials. Under the conditions of this study, the chelation rate and iron content of the WP-Fe chelate were 71.87 ± 1.60% and 113.11 ± 2.52 mg/g, respectively. Fourier transform infrared spectroscopy (FTIR), zeta potential, amino acid composition, and other structural analysis showed that WP-Fe is formed by the combination of carboxyl, amino and carbonyl with Fe2+. The WP-Fe chelate exhibits a honeycomb-like bulk structure different from that of WP. In addition, we predicted and established the binding model of ferrous ion and WP by molecular docking technology. After chelation, the free radical scavenging ability of the WP-Fe chelate was significantly higher than that of the WP. Overall, the WP-Fe chelate has high iron-binding capacity and antioxidant activity. We believe that peptides from different sources also have better iron binding capacity, and peptide iron chelates are expected to become a promising source of iron supplement and antioxidant activities

The Work of Instructors for New Socialist Countryside Construction

To meet the wishes and demands of the majority of farmers, it is necessary to steadily build a new socialist countryside, and actively promote urban-rural integration. With the guidance for new countryside construction as an opportunity, this paper studies and explores the working practice of new countryside construction instructors sent by Longyang Agricultural Technique Extension Station for various village committees (or offices) during 2007-2013. This paper analyzes and summarizes the results achieved and the main problems, and puts forth the corresponding recommendations. The results of the analysis can provide a reference for the instructors to carry out the guiding work for new countryside construction

Catalytic Radical Trifluoromethylalkynylation of Unactivated Alkenes

The trifluoromethylalkynylation of unactivated alkenes with alkynyl sulfones and Togni’s reagent was developed. The reaction was catalyzed by 2,4,6-trimethylpyridine, leading to various β-trifluoromethylated alkynes under metal-free conditions with a broad substrate scope and wide functional group compatibility. A mechanism involving catalytic nonchain radical processes is proposed

Silver-Catalyzed Decarboxylative Bromination of Aliphatic Carboxylic Acids

The silver-catalyzed Hunsdiecker bromination of aliphatic carboxylic acids is described. With Ag­(Phen)₂OTf as the catalyst and dibromoisocyanuric acid as the brominating agent, various aliphatic carboxylic acids underwent decarboxylative bromination to provide the corresponding alkyl bromides under mild conditions. This method not only is efficient and general but also enjoys wide functional group compatibility. An oxidative radical mechanism involving Ag­(II) intermediates is proposed

Mutations in the miRNA165/166 binding site of the HB2 gene result in pleiotropic effects on morphological traits in wheat

Leaf, spike, stem, and root morphologies are key factors that determine crop growth, development, and productivity. Multiple genes that control these morphological traits have been identified in Arabidopsis, rice, maize, and other plant species. However, little is known about the genomic regions and genes associated with morphological traits in wheat. Here, we identified the ethyl methanesulfonate-derived mutant wheat line M133 that displays multiple morphological changes that include upward-curled leaves, paired spikelets, dwarfism, and delayed heading. Using bulked segregant RNA sequencing (BSR-seq) and a high-resolution genetic map, we identified TraesCS1D02G155200 (HB-D2) as a potential candidate gene. HB-D2 encodes a class III homeodomain-leucine zipper (HD-ZIP III) transcription factor, and the mutation was located in the miRNA165/166 complementary site, resulting in a resistant allele designated rHb-D2. The relative expression of rHb2 in the mutant plants was significantly higher (P < 0.01) than in plants homozygous for the WT allele. Independent resistant mutations that disrupt the miRNA165/166 complementary sites in the A- (rHb-A2) and B-genome (rHb-B2) homoeologs showed similar phenotypic alterations, but the relative intensity of the effects was different. Transgenic plants expressing rHb-D2 gene driven by the maize UBIQUITIN (UBI) promoter showed similar phenotypes to the rHb-D2 mutant. These results confirmed that HB-D2 is the causal gene responsible for the mutant phenotypes. Finally, a survey of 1397 wheat accessions showed that the complementary sites for miRNA165/166 in all three HB2 homoeologs are highly conserved. Our results suggest that HB2 plays an important role in regulating growth and development in wheat

Simulation results.

<p>The figure plots the mean (A) genotype error and (B) clone frequency error as a function of the number of subsections. Each mean is computed over 100 simulated data sets. For each data set, the EM optimization is repeated from 10 different random initializations, and the results corresponding to the largest log likelihood are reported.</p