Vinylogous Acyl Compounds. XX. Reactivity and Toxicity of Aryl-substituted β-Chlorovinyl Ketones, β-Chlorovinyl Aldehydes, and β-Chlorovinyl Methyleniminium Salts Based on kinetic measurements, the nucleophilic replaceability of the chlorine in aromatic β-chlorovinyl ketones ArCO-CH CH-Cl ( 1 ), isomeric β-chlorovinyl aldehydes OCH CHC(Cl)Ar( 2 ), and corresponding β-chlorovinyl methyleniminium salts Me2N⊕;CH CHC(Cl)Ar X⊖ ( 3 ) is compared and related to toxicological findings. The chemical reactivity of these important synthetic building blocks increases in the order 2 < 1 < 3 , the acute toxicity (24 h LD50 i. p. in the mouse) shows the graduation 2 < 3 < 1 . Compounds of type 1 prove to be relatively toxic (LD50 24–42 mg/kg) and display a marked necrotic action after percutaneous absorption, whereas the aldehydes 2 have not only a minor acute toxicity (LD50 158–298 mg/kg) but also a somewhat less marked skin damaging activity. In addition, the LD50 values of selected β-chlorovinyl carbonyl compounds are compared with those of corresponding halogen-free compounds as well as of vinylogous carbonamidium salts ArCO CHCH N⊕R3X⊖. The latter, which can be used as synthetic equivalents of 1 , differ in both the reduced acute toxicity and missing skin damaging properties. 相似文献
Noscapine displays weak anticancer efficacy and numerous research efforts have attempted to generate more potent noscapine analogues. These modifications included the replacement of the N-methyl group in the 6′-position with a range of substituents, where N-ethylcarbamoyl substitution was observed to possess enhanced anticancer activity. Herein, we describe advances in this area, namely the synthesis and pharmacological evaluation of a series of N-sulfonyl and N-sulfamoyl noscapine derivatives. A number of these sulfonyl-containing noscapinoids demonstrated improved activities compared to noscapine. ((R)-5-((S)-4,5-Dimethoxy-1,3-dihydroisobenzofuran-1-yl)-4-methoxy-6-((1-methyl-1H-imidazol-4-yl)sulfonyl)-5,6,7,8-tetrahydro[1,3]dioxolo[4,5-g]isoquinoline) ( 14 q ) displayed sub-micromolar activities of 560, 980, 271 and 443 nM against MCF-7, PANC-1, MDA-MB-435 and SK-MEL-5 cells, respectively. This antiproliferative effect was also maintained against drug-resistant NCI/AdrRES cells despite high expression of the multidrug efflux pump, P-glycoprotein. 相似文献
Aza-enamines. IV. Proof of Enamine Character of N,N-Alkylated Hydrazones Given by N.M.R.- and U.V.-Spectroscopy Hydrazones of the type R1 CH N R2 with R1 = p-methoxyphenyl-, 1 , phenyl-, 2 , p-nitrophenyl-, 3 , ethyl-, 4 and R2 = morpholino-, a , piperidino-, b , dimethylamino-, c , pyrrolidino-, d and dicyclohexylamino-, e have been investigated with regard to spectroscopic analogy to enamines. The conclusion has been drawn that aldehydehydrazones act similar enamines. 相似文献
d-N.M.R.-Investigation of the Restricted Rotation at the -Bonding Increment. X. N-Substituted Thiocarbamic acid-O-Phenyl- and S-Ethylesters The free enthalpies of activation of the restricted rotation at the partial -double bond in thiocarbamic acid esters have been determined for (R1 = methallyl; R2 = me, et, iso-pr, cycl. hex; X S and Y O C6H5 respectively X O and Y S C2H5). The results have been compared with values, earlier observed for other mono- and dithiocarbamic acid esters, substituted at nitrogen analogously. 相似文献
Organic Phosphorus Compounds. XIII. Reaction of Vinylogous Chloromethylene Immonium Salts with Trialkyl Phosphites 3-Chloropropenylidene immonium salts of the type Cl CArCH CHNMe2⊕X⊖ don't react like chloromethylene immonium salts Cl CHNMe2⊕X⊖ with trialkyl phosphites according to the classical MICHAELIS -ARBUSOV principle (RO)3P + R′Cl → (RO)2P(O)R′ + RCl but lead to salts of 1-dimethylaminophosphonates (RO)2P(O) CH(NMe2 · HX) CHCClAr the structure of which is confirmed by two independent syntheses. Some characteristic reactions of the free dimethylaminophosphonates are described. 相似文献
An efficient synthesis of fused polycyclic 11-aryl-7,8,9,11-tetrahydro-1H-[1,2,3] triazolo[4,5-a]acridin-10(6H)-one derivatives is described in EtOH with high regioselectivity. This new procedure includes a three-component reaction of benzaldehyde, 1H-benzo[d] [1,2,3]triazol-5-amine and cyclohexane-1,3-dione under catalyst-free conditions, and has the advantages of one-pot reaction, milder reaction conditions, high yields and high regioselectivity. 相似文献
Copolymerizations of ethylene with 5‐vinyl‐2‐norbornene or 5‐ethylidene‐2‐norbornene under the action of various titanium complexes bearing bis(β‐enaminoketonato) chelate ligands of the type, [R1NC(R2)CHC(R3)O]2TiCl2 ( 1 , R1=Ph, R2=CF3, R3=Ph; 2 , R1=C6H4F‐p, R2=CF3, R3=Ph; 3 , R1=Ph, R2=CF3, R3=t‐Bu; 4 , R1=C6H4F‐p, R2=CF3, R3=t‐Bu; 5 , R1=Ph, R2=CH3, R3=CF3; 6 , R1=C6H4F‐p, R2=CH3, R3=CF3), have been shown to occur with the regioselective insertion of the endocyclic double bond of the monomer into the copolymer chain, leaving the exocyclic vinyl double bond as a pendant unsaturation. The ligand modification strongly affects the copolymerization behaviour. High catalytic activities and efficient co‐monomer incorporation can be easily obtained by optimizing the catalyst structures and polymerization conditions. 相似文献
A new and efficient method for the synthesis of 2‐vinylanilines from the reaction of arylhydrazine hydrochlorides with alkenes and diethyl ketone via a rhodium‐catalyzed C H activation is described. The oxidant‐free olefination reaction involves the in situ generation of an N NCR1R2 moiety as the oxidizing directing group thus providing an easy access to 2‐vinylanilines.
Dirhodium(II) acetate‐catalyzed reactions of N‐tosylhydrazones with dihydroquinazolinones bearing different types of N H bonds that give N3‐benzyl/alkyl‐2‐arylquinazolin‐4(3H)‐ones through Csp3 N bond formation by oxidative dehydrogenation and insertion of rhodium‐carbenoid into amide N H bond are reported for the first time. This method features good to excellent yields, good functional group tolerance, high regioselectivity and readily available starting materials.
A novel and efficient oxidative annulation of 2‐aminobenzamides with nitromethane has been developed for the chemoselective synthesis of N‐substituted 1,2,3‐benzotriazine‐4(3H)‐ones in moderate to excellent yields under transition metal‐free conditions. Two N N bonds were constructed in one pot via C N cleavage of nitromethane, which was selectively employed as the nitrogen synthon. The preliminary mechanistic studies revealed that this protocol proceeded under hypoiodite catalysis generated in situ.
A novel approach for C N bond formation was developed by iron‐catalyzed C C bond cleavage. Anilines and sulfonamides reacted smoothly with 2‐substituted 1,3‐diphenylpropane‐1,3‐diones to afford N‐alkylation products, in which the 1,3‐dicarbonyl group acts as a leaving group in the presence of an iron catalyst. The reversible C C bond cleavage plays a driving force to give the thermodynamically stable products. The method is complementary to the previous methods for C N bond formation. 相似文献
On the Coupling of 4-Substituted 2-Pyrazoline-5-ones with Quinone Diimine Cations; Detection of Isokinetic Relations The temperature dependence of the rate constant kK of the coupling reaction between pyrazoline-5-ones 1a – i and quinone diimine cations 2a , b is determined in dependence of the substituents at the coupling position (R3: H, NN Ar, CHAr–pyrazoline-5-one). The activation enthalpies are between 7 and 60 kJ mol−1 and the activation entropies between −132 and −19 J mol−1 K−1. An isokinetic relation with β = 106°C is found and a rate determining combination of the carbanions of 1a – i with 2a , b is proposed. Contrary to this, the 2-pyrazolin-5-ones 1j – l , n (R3: S CNH2NR) obey an isokinetic relation with β = −45°C. Taking into consideration the activation parameters, the low dependence of kK on the ionic strength, and the decrease of kK with the increase of the pK values of the couplers, a rate determining splitting off of R3 is assumed. 相似文献
On the Structural Analytical Application of „Anomalous”︁ Multiplets in Off-resonance Decoupled 13C NMR Spectra of CH CH Fragments The theoretical background of “anomalous” splitting of signals of molcular fragments CHCH in off-resonance decoupled 13C NMR spectra is described. The use of these splitting phenomena on the determination of vicinal H,H and geminal C,H coupling constants is demonstrated using simple examples. The possibilities to determine the configuration of double bonds are shown by other examples from the field of natural constituents chemistry. 相似文献
Stereoregular trans‐arylene‐silylene‐vinylene polymers of Mw=13100–34800 and PDI=1.6–2.9 of the general formulas CH2CH [ SiMe2C6H4‐SiMe2CHCH ] ( 16, 17, 18 ) and CH2CH [ (R)CHCHC6H4CHCH ] (where R= Me2Si‐p C6H4‐ SiMe2 , Me2Si‐m C6H4SiMe2 and Me2SiC6H4C6H4SiMe2 ) ( 19, 20, 21 ) have been effectively synthesized via silylative coupling (SC) homopolycondensation of bis(vinyldimethylsilyl)arenes ( 10, 12, 14 ) and cross‐polycondensation of 4‐(vinyldimethylsilyl)styrene ( 11 ) as well as cross‐copolycondensation of bis(vinyldimethylsilyl)arenes ( 10, 12 and 14 ) with 1,4‐divinylbenzene ( 9 ) catalyzed by [RuH(Cl)(CO)(PCy3)2] ( 7 ). Such highly stereoregular products cannot be synthesized via ADMET polycondensation or ring opening metathesis ROM or polyaddition of hydridosilanes to acetylenes. 相似文献
In this study, novel ferrocene-functionalized N-alkyl substituted pyrrole derivatives, namely 4-ferrocenyl-1-[3-(pyrrol-1-yl)propyl]-1H-1,2,3-triazole (Py3Fc), 4-ferrocenyl-1-[4-(pyrrol-1-yl)butyl]-1H-1,2,3-triazole (Py4Fc), and 4-ferrocenyl-1-[6-(pyrrol-1-yl)hexyl]-1H-1,2,3-triazole (Py6Fc), were synthesized via click reaction and the monomers were characterized by 1H NMR, 13C NMR, FTIR, and HRMS techniques. Redox properties of the monomers were investigated by cyclic voltammetry (CV) studies. Contrary to general literature, both Py4Fc and Py6Fc were electrochemically polymerized without loss in redox activity of ferrocene group. Moreover, click chemistry was utilized in post-polymerization functionalization. For this purpose, three azide-containing polypyrroles, P(Py3N3), P(Py4N3), and P(Py6N3) were electrochemically synthesized and subjected to click reaction in the presence of ethynylferrocene. CV studies of the post-polymerization functionalized polymers revealed quasi-reversible waves, while only P(Py6-post-Fc) showed the characteristic redox behavior of both polypyrrole and ferrocene. Thus, in this study preparation of a conducting homopolymers of pyrrole having covalently bonded ferrocene units was demonstrated and effect of spacer group is investigated. 相似文献
The p-tert-butylcalix[6]arene hexamide 2 and syn-1,3,5–trimethoxy-2,4,6-triamide 4 were synthesized by reaction of α-chloro-N,N-diethylacetamide and the corresponding calix[6]arenes 1 and 3 , respectively. 1H NMR spectroscopy shows that 2 is a mixture of different conformations whereas 4 is fixed in a cone conformation. Extraction experiments, (S-L) and (H2O–CDCl3) with picrate salts, indicate that 2 complexes both alkali metal (1:2 complex) and guanidinium salts (1:1 complex) but 4 complexes only guanidinium (1:1 complex). Incorporated in supported liquid membranes (Accurel® / o-nitrophenyl n-octyl ether) the calixarenes 2 and 4 transport guanidinium salts. The hexamide 2 is a more efficient carrier of guanidinium but the syn-1,3,5-trimethoxy-2,4,6-triamide 4 is much more selective. Both 2 and 4 are sufficiently lipophilic to give membranes that are stable over longer periods (weeks). 相似文献