نتایج جستجو برای: n substituted piperazinyl quinolones
تعداد نتایج: 1010427 فیلتر نتایج به سال:
A method is provided for preparing benzoprostacyclins by the free-radical-catalyzed tandem alkene insertion into a 1,4-bisoxy-substituted cyclopent-2-ene intermediate.
BACKGROUND Short sequence-specific heteropolymers of N-substituted glycines (peptoids) have emerged as promising tools for drug discovery. Recent work on medium-length peptoids containing chiral centers in their sidechains has demonstrated the existence of stable chiral conformations in solution. In this report, we explore the conformational properties of these N alpha chiral peptoids by molecu...
A series of novel 11b-substituted 1,6,7,11b-tetrahydropyrimido[6,1-a]- isoquinoline-2,4-diones and 4-thioxo-1,3,4,6,7,11b-hexahydropyrimido[6,1-a]isoquinolin-2- ones were synthesized, utilizing two alternative strategies for ring closure of tetrahydroisoquinoline intermediates obtained from N-phenethyl enaminones.
Effects of tannic acid on hatching of Heterodera glycines eggs were determined in vitro using three batches of eggs obtained from greenhouse cultures in Florida or from naturally infested field soil in Minnesota. A quadratic model fits the percentage egg hatch. Hatch increased with increasing tannic acid concentrations from 0 to about 39 mg/liter, then declined with further increases in concent...
Selenium substituents which are disposed β to an electron deficient centre, such as a carbocation p-orbital, or the π* orbital of an electron deficient p-system, interact in a stabilising way by a combination of C-Se hyperconjugation (σ(Se-C)-π* interaction), and a through-space homoconjugative n(Se)-π* interaction. The relative importance of these two modes of interaction is dependant on the e...
The arylation of mono-, di- and tetra-meso-bromophenyl-substituted porphyrins with the heteroarenes containing "acidic" C-H bonds, such as benzoxazole, benzothiazole and N-methylimidazole was studied in the presence of three alternative catalytic systems: Pd(dba)2/DavePhos/Cs2CO3, Pd(PPh3)4/PivOH/K2CO3 and Pd(OAc)2/Cu(OAc)2/PPh3/K2CO3. The first catalytic system was found to be successful in th...
New photoluminescent donor-acceptor-donor (DAD) molecules, namely 5'-aryl-substituted 2,5-bis(3-decyl-2,2'-bithiophen-5-yl)-1,3,4-oxadiazoles were prepared by palladium-catalyzed coupling from readily available compounds such as ethyl 3-decyl-2,2'-bithiophene-5-carboxylate and aryl halides. The obtained compounds feature increasing bathochromic shifts in their emission spectra with increasing a...
A series of donor-acceptor type co-crystals of fullerene (as the acceptor) and arylthio-substituted tetrathiafulvalene derivatives (Ar-S-TTF, as the donor) were prepared and their structural features were thoroughly investigated. The formation of co-crystals relies on the flexibility of Ar-S-TTF and the size matches between Ar-S-TTF and fullerene. Regarding their compositions, the studied co-cr...
A bicyclic guanidine-catalyzed Michael addition of 3-benzyl substituted oxindoles to N-maleimides has been developed to produce oxindole derivatives with a quaternary carbon chiral center at the 3-position in excellent yields and enantio- and diastereoselectivities. This is the first incorporation of N-benzylic α-branched succinimides into 3,3-disubstituted oxindoles.
A 4-year systematic survey for the presence of soybean cyst nematode Heterodera glycines in Ohio soybean fields was initiated in 1992. A total of 667 soybean fields in 63 counties was sampled. Heterodera glycines was present in 91 fields in 40 counties based on soil samples collected, and in one field in each of three additional counties based on soil samples submitted to the Plant and Pest Dia...
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