Combination of PhI(OAc)2 and 2-Nitropropane as the Source of Methyl Radical in Room-Temperature Metal-Free Oxidative Decarboxylation/Cyclization: Construction of 6-Methyl Phenanthridines and 1-Methyl Isoquinolines.

A room-temperature metal-free method for generating highly unstable methyl radical was realized from the combination of PhI(OAc)2 and 2-nitropropane, which provides an efficient approach to methylated phenanthridines and isoquinolines. The strategy was also extended to the generation of other alkyl radicals and a concise synthesis of Roxadustat.

Silver-catalyzed C2-selective direct alkylation of heteroarenes with tertiary cycloalkanols.

A silver-catalyzed regioselective C2-alkylation of heteroarenes with tertiary cycloalkanols under radical conditions was developed. This tandem process, which includes selective C-H activation, C(sp3)-C(sp3) bond cleavage, and C(sp3)-C(sp2) bond formation, affords a novel and environmentally friendly approach for the production of carbonyl-containing alkyl-substituted heteroarenes with moderate to good yields.

Copper/silver-mediated cascade reactions for the construction of 2-sulfonylbenzo[b]furans from trans-2-hydroxycinnamic acids and sodium sulfinates.

Efficient construction of 2-sulfonylbenzo[b]furans is achieved from readily available trans-2-hydroxycinnamic acids and sodium sulfinates mediated by the CuCl2·2H2O/AgTFA system under mild conditions. This unprecedented synthetic protocol provides expedient access to a series of products in one step via a protodecarboxylation/C-S bond formation/C-O bond formation cascade.

Inheritance of chlorantraniliprole resistance and fitness costs in a field population of Cnaphalocrocis medinalis (Lepidoptera: Pyralidae) in China.

BACKGROUND: Cnaphalocrocis medinalis is one of the major rice insect pests in Asia. Chlorantraniliprole is one of the most important insecticides for the control of C. medinalis. In this study, a field-resistant population and a susceptible strain of C. medinalis were used to evaluate the inheritance of chlorantraniliprole resistance and fitness costs in the field. RESULTS: The field-resistant population (Cm-RR) showed 128.4-fold resistance to chlorantraniliprole compared with the susceptible strain (Cm-SS). The dose-response of reciprocal cross progeny (F1 and F1') showed no significant difference, which indicated the inheritance of resistance to chlorantraniliprole in C. medinalis was autosomal. The degrees of dominance (D) of resistance for F1 and F1' were -0.19 and -0.05, respectively, indicating that the chlorantraniliprole resistance of C. medinalis was incompletely recessive inheritance. At the same time, significant differences between observed and expected mortalities of self-cross (F2 and F2') and backcross (BC and BC') progenies suggested chlorantraniliprole resistance is controlled by multiple genes. Furthermore, the Cm-RR population had a relative fitness of 0.32 with a substantially decreased pupation rate, emergence rate, fecundity, and substantially increased developmental time of larval and pupa stages. CONCLUSION: Current research showed that the inheritance of chlorantraniliprole resistance to C. medinalis was autosomal, incompletely recessive and multigene. The field-resistant population had a relative fitness of 0.32 when compared with the susceptible strain. This study provided valuable information for facilitating the development of chlorantraniliprole resistance management strategies. © 2024 Society of Chemical Industry.

Rhodium-Catalyzed Regioselective Formal Hydroacylation of Vinyl Epoxides toward Esters Involving ß-Carbon Cleavage.

Herein we disclose the first example of the formal hydroacylation reactions of vinyl epoxides with chelating aldehydes enabled by rhodium catalysis for the efficient construction of functionalized esters. Detailed investigations of the mechanistic pathway reveal that the presence of a 2-vinyl group is essential in contributing to the success of this regioselective reaction, which might proceed through ß-carbon cleavage as the key procedure.

The synthesis of N,N'-disulfanediyl-bis(N'-((E)-benzylidene)acetohydrazide) from (E)-N'-benzylideneacetohydrazide and S8.

Herein we report an oxidative coupling reaction for N-S/S-S bond formation from (E)-N'-benzylideneacetohydrazide and S8 to furnish substituted N,N'-disulfanediyl-bis(N'-((E)-benzylidene) acetohydrazide). It provides a direct approach for the synthesis of disulfides with good yields.

Rhodium-Catalyzed Ring-Opening Hydroacylation of Alkylidenecyclopropanes with Chelating Aldehydes for the Synthesis of γ,δ-Unsaturated Ketones.

The first intermolecular ring-opening hydroacylation of alkylidenecyclopropanes with chelating aldehydes through a rhodium-catalyzed acrylamide-promoted protocol is reported. This highly efficient catalytic system enables the direct synthesis of a diverse range of linear γ,δ-unsaturated ketones. Good functional group compatibility is demonstrated for the completely atom-economical and remarkably selective proximal C-C bond cleavage process. Mechanistic studies reveal that the bidentate coordination of N,N-dimethylmethacrylamide (L1) to the acylrhodium intermediates might facilitate the cyclopropane ring fragmentation and isomerization.

Rhodium-Catalyzed Synthesis of α,ß-Unsaturated Ketones through Sequential C-C Coupling and Redox Isomerization.

A novel Rh(I)-catalyzed sequential C-C coupling and redox isomerization between allylic alcohols and 1,3-dienes has been accomplished. This versatile protocol provides expeditious access to a broad range of polysubstituted α,ß-unsaturated ketones with excellent atom economy and regioselectivity.

[Transformation of Populus tomentosa with anti-PLD gene].

Antisense Phospholipase Dgamma( PLDgamma) gene was introduced into Populus tomentosa mediated by Agrobactrium tumefaciens. The young leaves of triploid populus were used as the material and the regeneration system of high frequency has been established. We have developed the traditional transgene method by Agrobactrium trmefaciens and obtained many transgenic plants of anti-PLDgamma gene. Tests showed that the transgenic plants can grow well on the culture medium with 0.7% NaCl.

[Analysis of arterial spin labeling in 33 patients with hypoxic ischemic encephalopathy].

OBJECTIVES: To evaluate the diagnostic value of arterial spin labeling (ASL) technology in newborns with hypoxic ischemic encephalopathy (HIE). METHOD: Seven full-term newborn infants without any history of asphyxia and other nervous system diseases were selected as the control and 33 full-term newborn infants were assigned into HIE group. The patients in HIE group were further divided into three subgroups (19 cases of mild, 6 cases of moderate and 8 cases of severe HIE) based on their clinical diagnosis. The control group and HIE group were examined with GE Signa EXCITE HD 3.0T superconducting MRI scanner with a head phase array coil. Both groups were scanned with conventional axial MRI (T1FLAIR, T2WI and T2FLAIR), 1HMRS (PRESS sequence) and ASL (FAIR). Original images of 1HMRS and ASL were processed by Functool software of ADW 4.3 workstation. ASL perfusion images were observed and the signal intensity values of the region of interest (bilateral gray, white matter and basal ganglia) of the two groups were quantitatively measured, and mean value were calculated and compared between groups. Statistical analysis was performed with SPSS 13.0 software, and statistically significant difference was set at P < 0.05. RESULT: The perfusion images of two groups were obtained perfectly. The signal intensity values of bilateral gray, white matter and basal ganglia of control group were 125.34 ± 11.76, 73.42 ± 11.67 and 173.65 ± 15.49, respectively and there was a statistically significant difference between the different areas. The signal intensity values of bilateral gray, white matter and basal ganglia of HIE group were 153.47 ± 11.72, 71.35 ± 10.37 and 217.13 ± 12.51, respectively. There was a statistically significant difference (P < 0.05) in the average signal intensity value of gray matter and basal ganglia, but there were no statistically significant difference (P > 0.05) in white matter between the two groups. CONCLUSION: ASL Perfusion technique can assess HIE comprehensively and accurately. Furthermore, it can evaluate the brain damage of hypoxic ischemia. The results provide a strong basis for clinical treatment.

[Size distributions and diurnal variations in the concentrations of polycyclic aromatic hydrocarbons in winter in urban and suburban Nanjing, China].

The contamination status and distribution characteristics of particulate polycyclic aromatic hydrocarbons (PAHs) were investigated in aerosols of urban and suburban Nanjing. A total of 17 PAHs were analyzed in the aerosol samples collected in daytime and nighttime during January 1st to 10th, 2010 in Nanjing University (NU) and Nanjing University of Information Science & Technology (NUIST). The PAH concentrations at the urban and suburban sites were 41.36-220.35 ng x m(-3) and 45.10-200.86 ng x m(-3), respectively, of which about 66%-67% was absorbed by fine particles (Dp < or = 2.1 microm). High levels of particulate PAHs were detected at both sampling sites with different diurnal variations. The higher total-PAH concentration occurred in the daytime at the urban site and in the nighttime at the suburban site. The change of prevailing wind direction and high-pressure weather system had significant impact on the variation of PAH concentrations, which were dominated by fine and coarse particles in urban and suburban regions, respectively. Difference in PAH size distributions was found for low weight molecular PAHs (LWM-PAH) and high weight molecular PAHs (HWM-PAH) in urban and suburban areas. The concentrations of 2-3 ring PAHs were higher at the suburban site than those at the urban site, whereas larger amounts of 4-6 ring PAHs were found at the urban site than at the suburban site. The concentration peaks in coarse particle size of high-molecular-weight PAHs found in our study were larger than those in some of the previous studies, which might be due to the high carbon content in coarse particles in the atmosphere at our sites. Analysis of diagnostic ratios indicated that the PAHs particles at both two sites have the same sources, including combustion of coal and biomass, vehicular exhaust and suburban industrial emission.

[Influence of inorganic additives on the distribution of polycyclic aromatic hydrocarbons in the smoke and ash from mosquito coils burning].

The influence of inorganic additives (NaCl, Na2CO3 and CaCO3) on the distribution of polycyclic aromatic hydrocarbons (PAHs) in the smoke and ash from mosquito coils burning was studied, GC-MS technique was applied to analyze the contents of 16 priority-controlled PAHs recommended by US EPA. The results show that 16 priority-controlled PAHs are detected in the smoke of mosquito coil without additives, characterized by the predominance of 2- to 3-ring PAHs, which are ranked as NaP (3.109 microg x g(-1)) > Phe (1.230 microg x g(-1)) > AcP (0.495 microg x g(-1)) > FluA (0.311 microg x g(-1)); the emission factors in the ash are also predominated by 2- to 3-ring PAHs, but the total PAHs emission factors in the ash are only 4.7% of those in the smoke. NaCl and Na2CO3 additives can not decrease the emission of PAHs but promote total emission factors and TEQ of PAHs in the smoke of mosquito coils increase remarkably. The best additive in this study is CaCO3. With the increase of the addition of CaCO3, the proportion for 2- to 3-ring PAHs in the smoke increases remarkably than that in the ash, while the status reverse for 5- to 6-ring PAHs. CaCO3 with mole fraction of 2.0% has the most excellent property to decrease total emission factors and TEQ of PAHs in the smoke of mosquito coils, and the total emission factors and TEQ of PAHs decrease 1.8% and 86.6% respectively compared with the control.

[Size distribution characteristics of polycyclic aromatic hydrocarbons of PM10 in foggy days in the north suburb of Nanjing].

Based on meteorological data and aerosol samples from Nov.15 to Dec.30,2007 in the north suburb of Nanjing, size distribution characteristics of polycyclic aromatic hydrocarbons (PAHs) in PM10 in foggy and sunny days were studied, and the concentrations of 16 PAHs were analyzed by gas chromatography with mass selective detection (GC-MS). The average concentrations of aerosols in the night (PM2.1 : 120.34 microg x m(-3; PM10 : 215.92 microg*m(-3) are close to those in the daytime (PM2.1 : 26.76 microg.m(-3); PM9.0 : 213.41 microg x m(-3)) in foggy days. The average concentrations of aerosols are higher in the night (PM2.1 : 71.45 microg x m(-3); PM9.0 : 114.33 microg x m(-3)) than those in the daytime (PM2.1 : 41.02 microg x m(-3); PM9.0 : 74.38 microg x m(-3)) in fine days. And we also find that the total concentrations of 16 PAHs in PM2.1 (49.97 ng x m(-3)) and PM9.0 (59.45 ng x m(-3)) in foggy days are 1.50 and 1.46 times of those (PM2.1 : 33.30 ng x m(-3); PM9.0 : 40.80 ng x m(-3)) in fine days separately. The average maximum concentrations of individual PAHs are fluoranthene, which are higher (PM2.1 : 7.98 ng x m(-3); PM9.0 : 9.99 ng x m(-3)) in foggy days than those (PM2.5 : 5.23 ng x m(-3); PM9.0 : 6.77 ng x m(-3)) in fine days, and the average concentrations of benzo-apyrene are higher in fog days (PM2.1 : 1.77 ng x m(-3); PM9.0 : 1.99 ng x m(-3)) than those in fine days (PM2.1 : 1.46 microg x m(-3); PM9.0 : 1.84 ng x m(-3)).Those results indicate that the fog processing could aggravate the pollution of PM2.5 and PM10 near the ground layer. Diurnal size distribution of total PAHs in PM10 is consistent with that of PM10 in foggy and sunny days, and size distribution investigated was bi-modal with a peak in accumulation particle mode and another peak in coarse particle mode aerosol. Size distributions of PM10 and total PAHs in PM10 are affected greatly by the day fog in daytime, while those are affected little by the night fog in night.