Synthesis and Herbicidal Activities of 2-Methylpropan-2-aminium O-Methyl 1-（Substituted Phenoxyacetoxy）alkylphosphonates

A series of 2-methylpropan-2-aminium O-methyl 1-（substituted phenoxyacetoxy）alkylphosphonates （5a-5o） was selectively synthesized by reacting the corresponding O,O-dimethyl l-（substituted phenoxyacetoxy）-alkylphosphonates with an excess of 2-methylpropan-2-amine.The results of preliminary bioassays show that the title compounds exhibit moderate to good herbicidal activities against Brassica napus and Echinochloa crusgalli.Furthermore,compounds 5a-5j,which show much higher activities than compounds 5k-5o,were selected to further evaluate their post-emergence herbicidal activity at a dosage of 150 g/ha（l ha=10000 m2）.Especially,2-methylpropan-2-aminium O-methyl 1-[2-（4-chloro-2-methylphenoxy）acetoxy]butylphosphonate（5h） shows 100％ inhibitory effect on the growth of Brassica juncea and Amaranthus retroflexus,which is comparable with the commercial herbicide 2,4-dichlorophenoxy acetic acid（2,4-D）.     

Synthesis and Herbicidal Activities of 3-（Substituted phenyl）isoxazole Derivatives

Several novel 3-(substituted phenyl)isoxazole derivatives were prepared from phenyl butan-l,3-dione. Their structures were confirmed by IH NMR, 1R, and CIMS. Preliminary bioassay showed that some of them exhibited good activities toward various weeds.     

Synthesis and Biological Activities of Substituted Triazolethione Schiff Base

Six novel Schiff bases have been synthesized by the condensation reaction of 4-amino-5-（4-pyridyl）-2,4-dihydro-1,2,4-triazole-3-thione with various benzaldehydes. The sfructures of the compounds have been confirmed by ^1H NMR, IR and elemental analysis. The preliminary bioassay indicated that the title compounds possessed good fungicidal activities to several vegetable pathogens.     

Synthesis and Crystal Structure of α-(3-Phenylureido)-α-(2,4-Dichlorophenyl) Methyl Phenylphosphinic Acid

1INThODUCT1ONInaprevi0uspaPer"',wereP0rtedthesyntheses0fsome1,3,4-diazaphospho-lidin-2-thione-4-oxidesandtheirhighselectiveherbicidalactivity.Althoughtherewereseveralreportsaboutthedesulphurisationofsomestraightchainthioureaderiva-tivest2'31,uptonow,thedesulphurisationreactionofcyclicthioureaderivativesutiliz-ingAgNO,-H,Osystemhasnotbeenstudied.InthispaPer,thedesulphurisation0fcis-3,4-diphenyl-5-(2,4-dichlorophenyl)-1,3,4-diazaphOSpholidin-2-thione-4-oasthecyclicsubstrateisrep0rtedfort…     

A Facile Synthesis of 0,0-Dialkyl-α-(Phenyl Carbamyloxy) Alkyl Phosphonates

TheC-ph0sphorylatedcarbamatederivativeshavereceivedspecialattentionbecauseoftheirpesticidalactivity.Wewereinterestedinfindingafacilemethodf0rthesynthesis0fthetitlec0mpounds.Therehavebeens0mereportsonthesynthesis0f(dialkylph0sphono)arylmethylcarbamates',whichwerepreparedbytreatingdialkylis0cyanat0phosphitewithsubstitutedbenzaldehydefoll0wedbyhydr0lysiswithwater.However,thismeth0dhassomelimitationsduetol0wyield,anddialkylisocyanatophosphiteisnoteasytoprepare.Inthestudy0fthenucIeophilicadditionr…     

Concise Synthesis of α-(Hydroxymethyl) Alkyl and Aryl Vinyl Ketones

2,4-Diketoesters 2 have first been reported as starting materials for the synthesis of a new class of α-hydroxymethyl-α,β-unsaturated ketones 3. Thus, under heterogeneous liquid–liquid medium in the presence of concentrated aqueous potassium carbonate as a base, both aliphatic and aromatic 2,4-dioxoalkanoates 2 react with aqueous formaldehyde to afford the corresponding ketones 3 in fair to good yields.     

Synthesis,Crystal Structure and Herbicidal Activity of Methyl(E)-α-(Methoxyimino)-2-((4-(3-chloro-5-(trifluoromethyl)-pyridine-2-yl)phenoxy)methyl)benzeneacetate

The title compound methyl(E)-α-(methoxyimino)-2-((4-(3-chloro-5-(trifluoromethyl) pyridine-2-yl)phenoxy)methyl)benzeneacetate(C23 H18 ClF3 N2 O4) has been synthesized and structurally characterized by 1 H and 13 C NMR, and HRMS. Its absolute molecular configuration was investigated by X-ray crystallography. The crystal crystallizes in monoclinic system, space group P21/c with a = 15.0928(7), b = 19.6070(10), c = 7.5535(5) ?, β = 98.176(5)°, V = 2212.6(2) ?3, Z =4, Dc = 1.438 g/cm3, F(000) = 984, μ(Mo Kα) = 0.231 mm-1, the final R = 0.0619 and wR = 0.1681 with 4034 observed reflections with I 2σ(I). The title compound has significant inhibitory rate against broadleaf weeds. They are all 100% under the dose of 37.5 g.a.i/ha, which was better than mesotrione.     

Synthesis and Herbicidal Activity of Novel β-Methoxyacrylate Derivatives Containing a Substituted Phenylpyridine Moiety

In this paper, a series of new β-methoxyacrylate derivatives containing a substituted phenylpyridine moiety was synthesized and bioassayed. The structures of all compounds were confirmed by nuclear magnetic resonance(NMR) and high-resolution mass spectrometry(HRMS). Preliminary bioassays demonstrated that compound 8d showed more than 95% inhibition against Brassica juncea and Chenopodium serotinum at 37.5 g a.i./10⁴ m², when compared with the positive control halauxifen-methyl at 150 g a.i./10⁴ m². The present work demonstrated that compound 8d exhibited the more promising herbicidal activity and may serve as a new herbicidal agent for herbicide.     

Synthesis and Characterization of Tri(organotin)Substituted Heteropolytungstates

ＳｙｎｔｈｅｓｉｓａｎｄＣｈａｒａｃｔｅｒｉｚａｔｉｏｎｏｆＴｒｉ（ｏｒｇａｎｏｔｉｎ）ＳｕｂｓｔｉｔｕｔｅｄＨｅｔｅｒｏｐｏｌｙｔｕｎｇｓｔａｔｅｓＹＡＮＧＱｉ－ｈｕａ,ＤＡＩＨｕｉ－ｃｏｎｇ,ＬＩＵＪｉｎｇ－ｆｕ（ＤｅｐａｒｔｍｅｎｔｏｆＣｈｅｍ...     

Synthesis and Herbicidal Activity of 3-Subsituted Amino-6-(substituted phenoxyl)pyridazine Derivatives

In recent years, many pyridazine derivatives have shown highly biological activities, such as fungicides, insecticides and herbicides. Especially, the researches of 3-(substituted phenoxyl)pyridazine derivatives have become the focus of pesticidal chemistry.     

Synthesis and properties of Alkyl α-D-Galactopyranoside

Alkyl α-D-galactopyranosides are sugar-based nonionic surfactants, and it is necessary to research their structure–property relationships since it is not quite clear that the change of the alkyl chain length has effects on a series of physicochemical properties. Here, alkyl α-D-galactopyranosides were prepared by galactose and alcohols through three steps including acetylation, coupling with alcohols in the presence of a catalyst stannic chloride, and deprotection. Furthermore, their water solubility and other properties were investigated. Alkyl α-D-galactopyranosides (4a ～ 4e, n = 6 ～ 10) were water soluble, and their dissolution process in water was an endothermic process. Nonyl α-D-galactopyranoside (4d) showed excellent foaming ability and foam stability. Octyl α-D-galactopyranoside (4c) had the strongest emulsifying ability for toluene and nonyl α-D-galactopyranoside (4d) had the strongest emulsifying ability for rapeseed oil. The critical micelle concentration (CMC) values and surface tension at the CMC were decreasing with increasing alkyl chain length. Their standard free energy of adsorption (ΔG_ads) was more negative than their standard free energy of micellization (ΔG_mic). The moisture-absorption abilities were weakening with increasing alkyl chain length. Alkyl α-D-galactopyranosides (4a ～4f) were thermally stable below 280°C. Alkyl α-D-galactopyranosides (4c ～4f) had the optical texture of the thermotropic liquid crystal smectic A phase.     

Synthesis of 3‐Alkyl and Arylapomorphines

The synthesis of 3‐alkyl and arylapomorphines 18–20 has been accomplished by using the Suzuki–Miyaura cross‐coupling reaction of vinyl‐ and allylhalide morphinanedienes or arylhalide apocodeines and arylboronic acids.     

Synthesis of 2-(Substituted Benzylideneamino)-4-(4′-hydroxyphenyl) Thiazoles and Their O-Glucosides

2-Amino-4-(4′-hydroxyphenyl) thiazole 1a was prepared from reaction between p-hydroxyacetophenone, thiourea, and iodine; compound 1a was treated with several (aryl/hetro aryl) aldehydes to form 2-(substituted benzylideneamino)-4-(4′-hydroxyphenyl) thiazoles 2a–j, which were glucosylated by using acetobromoglucose as a glucosyl donor to afford 2-(substituted benzylideneamino)-4-(2, 3, 4, 6-tetera-o-acetyl-4′-o-β-d-glucosidoxyphenyl) thiazoles 3a–j, which further on during deacetylation produced 2-(substituted benzylideneamino)-4-(4′-o-β-d-glucosidoxyphenyl) thiazoles 4a–j. These compounds were evaluated for biological activity, and their structure was confirmed by IR, NMR, mass spectra, elemental, and chemical analysis.

     

Total Synthesis of (-)-α-Pinguisene

In previous work from our laboratory, we demonstrated that α-carbonyl radical cyclization reactions can serve efficiently as key steps in total synthesis of natural products.1 In this presentation,we report the total synthesis of (-)-α-pinguisene from enone 1 via α-carbonyl radical cyclization.     

Combinatorial Synthesis of O-Pyrimidinyl Substituted Methyl-α-D-Glucopyranosides

Within last decade, many pyrimidinyl oxy substituted alcohols, aldehydes and carboxylic derivatives had been found with prominent bio-activities such as high herbicidal activities with wide spectrum. After extensively study of the relationship between structures and bioactivities, A brand-new scaffold combining both pyrimidinyl and glucoside moieties was designed and other building blocks were further introduced with the help of polymer-supported regioselective protecting groups. As shown below, a combinatorial synthesis was carried out by applying "mix-split" method to produce the following series of small compounds libraries both in solid-phase and liquid phase.     

Synthesis of Substituted (±)-3,4-Dihydrocoumarins Using H-Y Zeolite

Synthesis of substituted (±)-3,4 Dihydrocoumarins were prepared with the reaction between substituted cinnamic acid and phenol catalysed by ecofriendly solid-acid catalyst H-Y zeolite involving esterification followed by ring closure.     

Convenient Synthesis of α,α1 - bis (Substituted Furfurylidene) Cycloalkanones and Chalcones Under Microwave Irradiation.

Condensation of furfural with cycloalkanones and substituted acetophenones catalyzed by solid NaOH results in α, α¹-bis (substituted furfurylidene) cycloalkanones and chalcones in high yield under microwave irradiation for a duration of 2 minutes.