吡虫啉替代药剂的田间筛选试验

进行了吡虫啉替代药剂的田间筛选试验.小区试验表明,10 d后5%氟虫腈SC 750 mL/hm2、48%毒死蜱·氟虫腈EC 900 mL/hm2和25%吡蚜酮WP 300 g/hm2对褐飞虱和灰飞虱的防效均超过80%,对白背飞虱的防效超过75%,而10%吡虫啉WP 600 g/hm2对飞虱的防效小于50%;示范试验表明,10 d后3种药剂对稻飞虱的防效依次分别为82.6%、85.2%和76.9%,15 d后对麦田灰飞虱的防效分别为83.9%、79.9%和82.4%,明显好于吡虫啉.因此,氟虫腈、毒死蜱·氟虫腈和吡蚜酮可以作为吡虫啉的替代药剂,并就3种替代药剂的合理使用进行了探讨.     

Assembly of 4‐Substituted 3‐Nitro‐1,2,3,4‐tetrahydropyridines via Organocatalytic Michael Addition

An organocatalytic Michael addition of protected 2‐amino‐1‐nitroethanes to α,β‐unsaturated aldehydes followed by treatment with TFA afforded 4‐substituted 3‐nitro‐1,2,3,4‐tetrahydropyridines with good diastereoselectivity and excellent enantioselectivity. Good yields were observed in the case of β‐aryl‐substituted α,β‐unsaturated aldehydes as the substrates, while moderate yields were obtained when β‐alkyl‐substituted α,β‐unsaturated aldehydes were used.     

Thermodynamics of noncovalent interactions in hydrophobically‐substituted water‐soluble polymers from intrinsic viscosity measurements: Application to nucleobase‐substituted pullulans

Hydrophobically substituted water‐soluble polymers (HSWSP) act as associative thickeners through the reversible crosslinking from noncovalent interactions between the various groups on the polymer chains in aqueous solution. This article shows how the intrinsic viscosity (IV) of nonionic HSWSP can be used to define the thermodynamics of these interactions. Literature data on the IV of pullulans substituted by nucleobase ester groups (thyminylbutyryl and adeninylbutyryl) (Mocanu et al., Can J Chem, 1995, 73, 1933) are used as an exemplar of these procedures. The intramolecular crosslinking in these substituted pullulans is deduced to be “unimolecular” (association constant K₁ = 1 M^?1), as contrasted with the “bimolecular” behavior expected from the stacking of the free nucleobases; evidently the crosslinking results from hydrophobic interactions between the butyryl linking groups and the main chain. The results are compared with those from other HSWSP, and from cosolute binding systems. The use of the water–octanol partition coefficients of model systems to elucidate hydrophobic interactions in HSWSP, and of denaturant cosolutes (especially urea) to diagnose the presence and strength of these interactions, are also discussed. Emphasis is placed on the need for further such studies to identify the interactions underlying the rheological behavior of the nonionic HSWSP, and of the more common ionic types. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

乙氧羰基烯丙基取代的肟醚类化合物的研究

采用"一锅法"来研究这一反应。由酮肟1与氢化钠作用产生酮肟阴离子2,酮肟阴离子再与α-乙氧羰基乙烯基膦酸二乙酯3作用产生膦酸酯取代的碳负离子4,该碳负离子进一步与醛作用得到α-乙氧羰基烯丙基肟醚化合物,产率在73%～79%。     

取代吲哚-3-甲醛与3-甲基-1-苯基-5-吡唑啉酮的固相缩合反应

在无溶剂、无催化剂、微波辐射条件下,取代吲哚-3-甲醛与3-甲基-1-苯基-5-吡哇啉酮通过固相Knoevenagel缩合反应合成了一系列4-(取代吲哚基-3-次甲基)-3-甲基-1-苯基-5-吡唑啉酮,产物结构经IR,1H NMR确证.最佳反应条件为:n(吲哚-3-甲醛):n(3-甲基-1-苯基-5-吡哇啉酮)＝1....     

A convenient [hydroxy(tosyloxy)iodo]benzene-mediated one-pot synthesis of 2-arylimidazo[2,1-b]benzothiazoles

Several 2-arylimidazo[2,1-b]benzothiazoles (4) have been conveniently synthesized in one-pot reactions via α-tosyloxylation of enolizable ketones (1) using [hydroxy(tosyloxy)iodo]benzene 2 in acetonitrile, followed by treatment with 2-amino-6-(substituted)benzothiazoles (3). The present protocol offers several advantages towards general access of 2-arylimidazo[2,1-b]benzothiazoles, including an intriguing alternative to the literature protocols, a readily available nontoxic reagent, operational simplicity and an environmentally benign procedure.     

用密度泛函理论研究多溴二苯并噻吩的热力学性质

The thermodynamic properties of 135 polybrominated dibenzothiophenes (PBDTs) in the gaseous state at 298.15 K and 1.013×105 Pa, are calculated using the density functional theory (the B3LYP/6-311G**) with Gaussian 03. Based on these data, the isodesmic reactions are designed to calculate the standard enthalpy of formation (ΔfHө) and the standard Gibbs energy of formation (ΔfGө) of PBDTs. The relations of these thermodynamic parameters with the number and position of bromine substituents (NPBS) are discussed, and it is found that there exist good correlations between thermodynamic parameters (including heat capacity at constant volume, entropy, enthalpy, free energy, ΔfHө, ΔfGө) and NPBS. The relative stability order of PBDT congeners is proposed theoretically based on the relative magnitude of their ΔfGө. In addition, the values of molar heat capacities at constant pressure (Cp,m) for PBDT congeners are calculated.     

Diastereoselective hydrogenation of 4-(phosphonomethyl)-2-pyridinecarboxylic acid

A Pd–Rh mixed metal catalytic system was developed that is able to hydrogenate 4-(phosphonomethyl)-2-pyridinecarboxylic acid to give 4-(phosphonomethyl)-2-piperidinecarboxylic acid with a cis selectivity of up to 98% with acceptable reaction time and without leading to metal contamination of the product. This revised version was published online in June 2006 with corrections to the Cover Date.     

2006年登记或上市的农药品种

概述了2006年世界农药公司登记或上市的38个农药品种,其中杀菌剂15个,杀虫杀螨剂15个,除草剂6个,植物生长调节剂2个。     

联吡啶钌配合物对末端炔烃的催化

以6,6＇-二甲基-2,2＇-联吡啶为配体合成了二水合氯化顺一二氯·二（6,6＇-二甲基-2,2＇联吡啶）合钌（Ⅲ）配合物,进一步用三氟甲基磺酸银脱氯得到三（三氟甲基）磺酸顺一二水·二（6,6＇-二甲基-2,2＇联吡啶）合钌（Ⅲ）配合物．研究了后者对1-己炔、苯乙炔和丙炔酸乙酯环三聚反应的催化作用．实验结果显示环三聚产物具有区域选择性：产物只有1,2,4一三取代苯与1,3,5-三取代苯两种同分异构体,且主要为1,2,4一三取代苯．催化机理研究表明,三（三氟甲基）磺酸顺一二水·二（6,6＇-二甲基-2,2＇联吡啶）合钌（Ⅲ）中的两个水分子配体首先被两分子炔烃取代生成π-炔基配合物,然后通过氧化偶联反应得到钌杂环戊二烯配合物;第三个炔烃分子经由插入反应或双烯加成反应生成钌杂环庚三烯或7一钌杂双环[2．2．1]-2,5-庚二烯中间体,随后发生还原消除反应得到三取代苯．