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The tandem catalysis of ring-closing metathesis/atom transfer radical reactions was investigated with the homobimetallic ruthenium-indenylidene complex [(p-cymene)Ru(μ-Cl) 3 RuCl(3-phenyl-1-indenylidene)(PCy 3 )] (1) to generate active species in situ. The two catalytic processes were first carried out independently in a case study before the whole sequence was optimized and applied to the synthesis of several polyhalogenated bicyclic γ-lactams and lactones from αω-diene substrates bearing trihaloacetamide or trichloroacetate functionalities. The individual steps were carefully monitored by 1 H and 31 P NMR spectroscopies in order to understand the intimate details of the catalytic cycles. Polyhalogenated substrates and the ethylene released upon metathesis induced the clean transformation of catalyst precursor 1 into the Ru(II)-Ru(III) mixed-valence compound [(p- cymene)Ru(μ-Cl) 3 RuCl 2 (PCy 3 )], which was found to be an efficient promoter for atom transfer radical reactions under t...

The anion of the title compound, simply generated in the presence of catalytic amount of triethylamine, acts as nucleophilic acylating equivalent of formaldehyde reacting with both common electrophilic olefins or aldehydes to give moderate to good yield of Michael or aldol adducts respectively, which are easily hydrolized by dilute acid at ambient to temperature to afford the corresponding aldehydes. https://www.lookchem.com/CASDataBase_759-05-7.htm

Treatment of a thallium(I) carboxylate with 1 molar equivalent of bromine gives the corresponding thallium(III) carboxylate dibromide.High yields of primary alkyl bromides are obtained if the thallium(III) carboxylate dibromide is treated with 0.5 mol equiv. of bromine in refluxing carbon tetrachloride.Pyrolysis of the thallium(III) derivative in the absence of added bromine gives a low yield of the corresponding alkyl bromide.The use of thallium(I) carboxylates for the preparation of alkyl bromides in high yields is limited to the salts of primary carboxylic acids.A simple procedure for the preparation of alkyl bromides from carboxylic acids using thallium(I) carbonate has been developed. https://www.lookchem.com/CASDataBase_75-26-3.htm

The present invention relates to a process for the synthesis of tapentadol intermediates comprising the following route of synthesis: (I) → (II) → (III) → (IV) → (V). https://www.lookchem.com/CASDataBase_175591-22-7.htm

A cost-effective task-specific ionic liquid, 2-hydroxyethylammonium formate, efficiently promotes the condensation of nitroalkanes with various aldehydes to produce β-nitrostyrenes in high to excellent yields at room temperature. This reaction does not involve any hazardous organic solvent and toxic catalyst. The ionic liquid is recovered and recycled for subsequent reactions. In addition, a novel mechanism has been proposed invoking ambiphilic dual activation influence of the ionic liquid. https://www.lookchem.com/CASDataBase_102-96-5.htm

(Matrix presented). A new class of sterically hindered phosphines based on a phospha-adamantane framework is described. Arylation or alkylation of the 1,3,5,7-tetramethyl-2,4,8-trioxa-6-phospha-adamantane system allows for the preparation of tertiary phosphines suitable for use in palladium-catalyzed cross-coupling reactions. For example, use of a catalytic system incorporating Pd 2 (dba) 3 and 1,3,5,7-tetramethyl-2,4,8-trioxa-6-phenyl-6-phospha-adamantane is shown to promote the Suzuki cross-coupling of aryl iodides, bromides, and activated chlorides with a variety of aryl boronic acids at room temperature in a few hours with high yields. https://www.lookchem.com/CASDataBase_10273-89-9.htm

Carbon-templated mesoporous ZSM-5 zeolites were synthesized directly avoiding a drying process. Carbon nanoparticles were simply mixed into synthesis precursor of ZSM-5 and hydrothermally treated by microwave irradiation. The amount of mesopores formed inside the ZSM-5 single crystals was controllable by adjusting the amount of carbon used. For comparison, mesoporous ZSM-5 zeolites have also been synthesized under hydrothermal conditions. The influence of microwave irradiation on mesoporous ZSM-5 materials was thoroughly investigated by using nitrogen adsorption/desorption studies and 27 Al MAS NMR. The nature of acid sites both in the micropores (internal) and on the surface of mesopores (external) was investigated by in situ FTIR spectroscopy using pyridine (Py) and 2′,6′-di-tert-butylpyridine (DTBPy) as a probe molecules. Mesoporous ZSM-5 prepared by microwave synthesis showed higher catalytic activity in the bulky molecular reaction of 2′,4′- dimethoxyacetophenone (2′,4′-DMAP) with...

With n-BuLi/KO-t-Bu, protons are removed from the hydroxyl and methyl groups of cresols 5 to give dianions 6 in yields of 85percent (ortho), 95percent (meta), and 42percent (para).These dianions react with alkyl halides, Me3SiCl, Bu3SnCl, CO2, and oxidizing agents at carbon only and with dialkyl sulfates at both carbon and oxygen.Thus phenol derivatives bearing primary alkyl groups can be prepared from the corresponding methylphenols via dianions 6. https://www.lookchem.com/CASDataBase_100-84-5.htm

Delaminated materials ITQ-2, ITQ-6 and ITQ-18 are very efficient catalysts of zeolitic nature for the synthesis of diamino diphenyl methane (DADPM), the polyamine precursor in the production of MDI for polyurethanes. The exfoliation process results in excellent accessibility of their active sites to reactant molecules as well as fast desorption of products. These catalysts present higher activity and slower rates of deactivation than their corresponding zeolites. Moreover, the topology of the delaminated structure imposes a precise control of the isomer distribution, offering an additional flexibility in the synthesis of DADPM. By optimizing the process conditions it is possible to achieve final DADPM crude under industrial production specifications with ITQ-18. This catalyst represents a real chance for replacing HCl in the industrial production of DADPM. https://www.lookchem.com/CASDataBase_101-77-9.htm

Sulfoxide ligation to Pd(II) salts is shown to selectively promote C-H oxidation versus Wacker oxidation chemistry and to control the regioselectivity in the C-H oxidation products. A catalytic method for the direct C-H oxidation of monosubstituted olefins to linear (E)-allylic acetates in high regio- and stereoselectivities and preparatively useful yields is described. The method using benzoquinone as the stoichiometric oxidant and 10 mol % of Pd(OAc) 2 or Pd(O 2 CCF 3 ) 2 as the catalyst in a DMSO/AcOH (1:1) solution was found to be compatible with a wide range of functionality (e.g., amides, carbamates, esters, and ethers, see Table 2). Addition of DMSO was found to be critical for promoting the C-H oxidation pathway, with AcOH alone or in combination with a diverse range of dielectric media, leading to mixtures favoring Wacker-type oxidation products (Tables 1, S3). To explore the role of DMSO as a ligand, the bis-sulfoxide Pd(OAc) 2 complex 1 was formed and found to be an effec...

A homogeneous visible light photoredox TEMPO-mediated selective oxidation of primary alcohols to the corresponding carbonyl compounds was developed using molecular oxygen from air as the terminal oxidant. Ru(bpy) 3 (PF 6 ) 2 (bpy: bipyridyl) and Ir(dtb-bpy)(ppy) 2 (PF 6 ) (dtb-bpy: 4,4′-di-tert-butyl-2,2′- bipyridyl; ppy: 2-phenylpyridine) were used as the sensitizers. A homogeneous visible light photoredox TEMPO-mediated selective oxidation of primary alcohols to the corresponding carbonyl compounds was developed. Molecular oxygen from air was the terminal oxidant. Copyright https://www.lookchem.com/CASDataBase_7311-34-4.htm

The chemistry of an alkylstrontium halide analogue was examined. In the presence of metallic strontium, the Barbier-type alkylation of esters with alkyl iodides proceeded smoothly at room temperature, under argon, to afford the corresponding dialkylated alcohols in good yields. Wiley-VCH Verlag GmbH & Co. KGaA, 2005. https://www.lookchem.com/CASDataBase_103-05-9.htm

Unsymmetrically coupled biaryls are synthesized in high yield starting from different aryl bromides and bis(pinacolato)diboron by carrying out the Miyaura borylation reaction followed by the Suzuki-Miyaura reaction in the same reaction pot over 1-2 mol % SiliaCat DPP-Pd. The SiliaCat DPP-Pd catalyst is air-stable and the method does not require the use of inert conditions. The use of non-toxic isopropanol or 2-butanol as reaction solvent further adds to the environmental benefits of this new green synthetic methodology. https://www.lookchem.com/CASDataBase_4423-09-0.htm

Two-fold extrusion reactions of 1,3,4-thiadiazolines 1 provide a convenient stereoselective route to unhindered Z-olefins.An improved preparation of the thiadiazolines involves reaction of an aldehyde with H2S-hydrazine, followed by in situ oxidation of the intermediate predominantly trans thiadiazolidine 2.Stereospecific extrusion of nitrogen yields the cis-thiirane which upon treatment with triphenylphosphine affords the corresponding Z-alkene in good yields. https://www.lookchem.com/CASDataBase_10374-74-0.htm

The phase transformation of α-Na 3 AlH 6 to β-Na 3 AlH 6 was characterized by in situ DSC and high-temperature X-ray diffraction methods. The detection of the phase transformation from the α- to the β-polymorph requires rapid heating rates and a very fast data acquisition. The influence of the preparation method on the stability of both polymorphic forms most probably originates from different particle sizes of the parent samples. https://www.lookchem.com/CASDataBase_7646-69-7.htm

A series of 5-substituted 1H-tetrazole were efficiently prepared by InCl3 catalyzed (10 mol %) from structurally divert organic nitriles with sodium azide under the influence of microwave irradiation. The present protocol was successfully applied to the aliphatic, aryl, benzylic and heterocyclic nitriles and corresponding 5-substituted 1H-tetrazole were obtained in good to excellent yield (70-96%). This method gives remarkable advantages such as short reaction time, simple work-up procedure and economical beneficial. https://www.lookchem.com/CASDataBase_18039-42-4.htm

The reduction of dimethyl and diphenyl sulfoxides, and of alkyl and arylbenzyl sulfoxides to the corresponding sulfides can be carried out using sodium bromide without solvent or benzyl bromide in dimethylformamide, mostly through an oxidation-reduction cycle catalyzed by developing hydrobromic acid. https://www.lookchem.com/CASDataBase_766-92-7.htm

Photolysis of the Diels-Alder adduct of 3,6-di-tert-butyl-o-benzoquinone and cyclobutadiene at ice-bath temperatures afforded the bicyclooctatriene 12.During warming to room temperature, this hydrocarbon underwent kinetically first-order valence isomerization to provide 5 and its bond shift isomer 4.This finding adumbrated the facility with which 4 and 5 are interconverted.Reaction of this cyclooctatetraene mixture with N-methyltriazolinedione gave urazoles 16 and 17 as chromatographically separable entities.Like 13, the related cycloadduct of 12 wherein both bridgehead tert-butyl groups exhibit restricted rotation , the angular tert-butyl substituent in 17 is sterically perturbed.Hydrolysis-oxidation of either 16 or 17 returned only mixtures of 4 and 5 because of their rapid bond shifting rates.When the equilibrium constant between these two isomers was determined by 1H NMR spectroscopy, it was found that 5, the apparently more congested compound, was the more stable in CDCl3 solution...

Carboxylation reactions of diamines were found to proceed rapidly and non-catalytically, producing corresponding cyclic ureas in excellent yields and selectivities when 2-pyrrolidone (2-PY) was used as a solvent. A similar promoting effect with 2-PY was also observed for the carboxylation of monoamines by carbon dioxide (CO 2 ). Most notably, the carboxylation reactions of mono- and diamines conducted in 2-PY afforded 2–4 times higher yields of corresponding dialkyl ureas and cyclic ureas compared with those in N-methyl-2-pyrrolidone (NMP). Such a dramatic promoting effect using 2-PY is believed to be associated with the multiple hydrogen bonding interactions between 2-PY and the CO 2 -containing species of amines. Due to such favorable interactions, carboxylation reactions seem to be more facilitated in 2-PY than in NMP. (Figure presented.). https://www.lookchem.com/CASDataBase_1792-17-2.htm

A one-step substitution of a single chloride anion of the Grubbs-Hoveyda second-generation catalyst with a 2,4,6-triphenylbenzenethiolate ligand resulted in an active olefin metathesis catalyst with remarkable Z selectivity, reaching 96% in metathesis homocoupling of terminal olefins. High turnover numbers (up to 2000 for homocoupling of 1-octene) were obtained along with sustained appreciable Z selectivity (>85%). Apart from the Z selectivity, many properties of the new catalyst, such as robustness toward oxygen and water as well as a tendency to isomerize substrates and react with internal olefin products, resemble those of the parent catalyst. https://www.lookchem.com/CASDataBase_7433-56-9.htm

A versatile metal- and base-free direct reductive amination of aldehydes with amines using formic acid as a reductant under the catalysis of inexpensive BF 3 ·Et 2 O has been developed. A wide range of primary and secondary amines and diversely substituted aldehydes are compatible with this transformation, allowing facile access to various secondary and tertiary amines in high yields with wide functional group tolerance. Moreover, the method is convenient for the late-stage functionalization of bioactive compounds and preparation of commercialized drug molecules and biologically relevant N-heterocycles. The procedure has the advantages of simple operation and workup and easy scale-up, and does not require dry conditions, an inert atmosphere or a water scavenger. Mechanistic studies reveal the involvement of imine activation by BF 3 and hydride transfer from formic acid. https://www.lookchem.com/CASDataBase_102-05-6.htm

Reduction of structurally different carbonyl compounds, such as aldehydes, ketones, α,β-unsaturated enals and enones, acid chlorides, and imines was accomplished efficiently using high capacity ionene based borohydride reagents. Aldehydes and imines were reduced to the corresponding alcohols and amines in excellent yields in methanol at ambient temperature while ketones and acid chlorides were reduced in iso-propanol and THF-MeOH at reflux. Chemoselective reduction of aldehydes over ketones was achieved successfully with these reagents. Complete regioselectivity was also observed in the reduction of α,β-unsaturated aldehydes and ketones. https://www.lookchem.com/CASDataBase_17849-38-6.htm

Hemiaminals of trifluoroacetaldehyde are new trifluoromethylating agents. These reagents are synthesised from amines and gaseous trifluoroacetaldehyde. tBuONa is able to deprotonate the hemiaminals to form trifluoromethyl anion equivalents CF 3 CH(O - )NMe 2 . The trifluoromethyl anion has been transferred from such intermediates to benzaldehyde yielding phenyl (trifluoromethyl) methanol. https://www.lookchem.com/CASDataBase_75-90-1.htm

Cyclic amines are ubiquitous core structures of bioactive natural products and pharmaceutical drugs. Although the site-selective abstraction of C-H bonds is an attractive strategy for preparing valuable functionalized amines from their readily available parent heterocycles, this approach has largely been limited to substrates that require protection of the amine nitrogen atom. In addition, most methods rely on transition metals and are incompatible with the presence of amine N-H bonds. Here we introduce a protecting-group-free approach for the α-functionalization of cyclic secondary amines. An operationally simple one-pot procedure generates products via a process that involves intermolecular hydride transfer to generate an imine intermediate that is subsequently captured by a nucleophile, such as an alkyl or aryl lithium compound. Reactions are regioselective and stereospecific and enable the rapid preparation of bioactive amines, as exemplified by the facile synthesis of anabasine an...

Various substituted ferrocenes have been trialed as catalysts in the nonclassical Polonovski reaction for N-demethylation of N-methyl alkaloids. Earlier studies suggest that conditions facilitating a higher ferrocenium ion concentration lead to superior outcomes. In this regard, the bifunctional ferrocene FcCH 2 CO 2 H, with electron donor and acceptor moieties in the same molecule, has been shown to be advantageous for use as a catalyst in the N-demethylation of a number of tertiary N-methylamines such as codeine, thebaine, and oripavine. These substrates are readily N-demethylated under mild conditions, employing sub-stoichiometric amounts of the substituted ferrocene at ambient temperature. These reactions are equally efficient in air and may also be carried out in one pot. Georg Thieme Verlag Stuttgart · New York. https://www.lookchem.com/CASDataBase_76-57-3.htm

A concise and efficient synthetic approach to 2α-(ω- hydroxyalkoxy)-1α,25-dihydroxyvitamin D 3 (4a-c), including 2-epi-ED-71, was developed starting from D-glucose as a chiral template for the construction of the 2α-modified A-ring precursors (11a-c). It was found that the best ligand for the bovine thymus vitamin D receptor (VDR) in this series is 4b, which has 1.8 times greater binding affinity for the bovine thymus VDR than that of the natural hormone 1. Interestingly, potency in the induction of HL-60 cell differentiation for 4a-c was almost the same or weaker than that of 1 despite the strong binding affinity for the VDR. Next, we were interested in the "double modification" of 1 based on 4a-c with C20-epimerization, affording 2α-(ω-hydroxyalkoxy)-20-epi-1α, 25-dihydroxyvitamin D 3 (20-epi-4a-c). All three 2α-substituted 20-epi analogues of 1 (20-epi-4a-c) exhibited stronger binding affinities for the VDR, and their conformations in the ligand binding domain of VDR wer...

We report an efficient approach for direct alkoxycarbonylation of furans as well as other heteroarenes via a one-step copper-mediated reaction of three components (i.e., heteroarene, alcohol, and CHCl 3 ). The copper additive was confirmed to simultaneously promote the reaction in three pathways: oxidant cracking, single electron transfer, and alcoholysis. By means of this protocol, various functionalized furancarboxylates and other heteroarenecarboxylates were facilely obtained in moderate to good yields. https://www.lookchem.com/CASDataBase_4282-32-0.htm

Aromatic β-amino ketones/alcohols such as adrenalone play an important role in some stereoselective synthesis of pharmaceuticals. Unfortunately, the transformation of aromatic β-amino ketones to their chiral alcohols has been carried out chemically as no corresponding biocatalyst has been available. Here, a novel carbonyl reductase responsible for the reduction of adrenalone to (R)-(-)-epinephrine was identified and characterized from Kocuria rhizophila. This enzyme was purified to homogeneity by ammonium sulfate precipitation followed by ion-exchange column chromatography, hydrophobic chromatography and gel chromatography. The purified enzyme yielded pure (R)-enantiomer product with high activity and utilized NADH as the cofactor. The enzyme had special significance by showing selectivity for many aromatic β-amino ketones/alcohols such as 2-amino-acetophenone, 2-amino-4′- hydroxyacetophenone, isoproterenol and ephedrine. The maximum reaction rate (V max ) and apparent Michaelis-Menten...

Oxazolidinones were effectively prepared from N-carbamylamino alcohols by treatment with nitrous acid, via N-nitroso compound as the intermediate. A new route to (R)-4-benzyloxazolidinone was developed starting from DL- phenylalanine, utilizing D-hydantoinase-catalyzed enantioselective hydrolysis of 5-benzylhydantoin under the dynamic kinetic resolution conditions, and the subsequent reduction to the precursor for the above-mentioned cyclization reaction, by taking advantage of the intermediates bearing an N-carbamylamino functionality. https://www.lookchem.com/CASDataBase_102029-44-7.htm

The dissociation yield and branching ratio in CO2 laser-induced multiphoton dissociation (MPD) of C2HF5 were investigated.In order to distinguish the two primary dissociation pathways (C2HF5 -> C2F4 + HF, E a =71.6 kcal/mol; C2HF5 -> CF3 + CHF2, E a =93.5 kcal/mol), Br2 was employed as an excellent scavenger of radicals and C2F4.The scavenged products were CBrF3, CHBrF2, CBr2F2, and C2Br2F4.The yield of C2Br2F4 originating from HF elimination was much smaller than those of CBrF3 and CHBrF2 from C-C bond rupture.The pulse energy dependence of the product distribution demonstrates that the primarily produced radicals were further photolyzed within the laser pulse (CF3 + nhν -> CF2 + F, and CHF2 + n'hν -> CF2 + H) to yield CBr2F2.The secondary photolysis of the radicals was also confirmed by real-time monitoring of infrared emission from HF * and DF * generated in the MPD of C2DF5 in the presence of H2 as an F atom scavenger.In the MPD of neat C2HF5, the formation of C2F...

The invention relates to a 5-amino-2,4,6-triiodo m-phthalic acid derivative as shown in the general formula I and salt, hydrate or solvate thereof, wherein substituent groups R1, R2, R3 and R4 are as defined in the specification. The invention also relates to a compound as shown in the general formula I and also relates to an application of the compound and its salt, hydrate or solvate in the preparation of iopromide. https://www.lookchem.com/CASDataBase_73334-07-3.htm

(Chemical Equation Presented) Linear (n = 2-18) and cyclic oligomers (n = 3-8) of a cyclohexylether-δ-amino acid (COA) were prepared in high yield and stereopurity. CD spectra of the linear oligomers were indicative of secondary structure formation. X-ray crystal structures of cyclic COA oligomers revealed hydrophobic packing and internal 5- and 10-membered-ring hydrogen bonds. Ether and amide oxygens reside preferably in an ap orientation. This conformational locking is apparently broken by a C-2 substituent in an asymmetric cyclotrimer, for which a zeolithe-like tubular structure was found. https://www.lookchem.com/CASDataBase_74111-21-0.htm

CH 2 ClCHCl 2 was photolyzed with a focusing geometry using the P(24) line of the 10.6 μm CO 2 band (940.6 cm -1 ).The final products of neat photolysis were cis- and trans-CHCl=CHCl, CH 2 =CCl 2 , CH 2 =CHCl, CH CCl, CH CH, and C 4 H 2 .The relative yield of CH 2 =CCl 2 in particular was strongly dependent on CH 2 ClCHCl 2 pressure and sensitive to the addition of H atom containing molecules.A series of diagnostic experiments shows that the dichloroethene isomers are formed by three different processes, i.e., infrared multiphoton decomposition, collision-induced decomposition, and radical chain reaction.Infrared multiphoton decomposition and collision-induced decomposition give rise to cis- and trans-CHCl=CHCl predominantly, while the radical chain reaction generates the dichloroethane isomers in comparable amounts at high reactant pressures, the most probable initiation step being the C-Cl bond-scission reaction of the parent molecule.Formation mechanisms for other minor products...

Glycerol phosphate oxidase from Streptococcus pneumoniae (GPO S.pne ) was purified and characterized. By the actions of GPO S.pne and dihydroxyacetone phosphate (DHAP)-dependent aldolases, various ketoses including rare sugars were synthesized with glyceraldehydes as acceptors in a one-pot four-enzyme system. https://www.lookchem.com/CASDataBase_17598-82-2.htm

Some differences were observed in the solid- and liquid-phase benzylic oxidation of 2-(hydroxy- or dialkylamino)methyl-4,6-di-tert-butylphenols.Oxidation of these semi-hindered phenols with lead tetraacetate gave a new compound: 3,5-di-tert-butyl-ortho-benzoquinone diacylal.Keywords: semi-hindered phenols, synthesis, aldehyde, benzylic alcohol, oxidation, liquid phase, solid phase. https://www.lookchem.com/CASDataBase_1020-31-1.htm

A simple and efficient protocol for the chemoselective mono-N-Boc protection of various structurally diverse amines with di-tert-butyl dicarbonate using 1,1,1,3,3,3-hexafluoroisopropanol (HFIP) as solvent and catalyst is described. The catalyst can be readily separated from the reaction products and recovered for direct reuse. No competitive side reactions such as formation of isocyanate, urea, and N,N-di-Boc were observed. α-Amino alcohols afforded the N-Boc derivatives without oxazolidinone formation. Georg Thieme Verlag Stuttgart. https://www.lookchem.com/CASDataBase_42116-44-9.htm

Jaspamide (Jasplakinolide), a marine cyclodepsipeptide, was synthesised from tripeptide fragment 4 and (2S,4E,6R,8S)-8-benzoyloxy-2,4,6-trimethylnon-4-enoic acid (3). The tripeptide fragment was prepared from β-tyrosine derivative 6, Boc-2-bromoabrine (8) https://www.lookchem.com/CASDataBase_102396-24-7.htm

In this study we synthesized the water-soluble polymeric prodrugs possessing a 4-methylcatechol (4MC) derivative as a side chain by mechanochemical solid-state copolymerization. 1-benzoyl-4-methylcatechol (Bz4MC) was selected as a model compound of 4MC, and its methacryloyl derivative (1) was synthesized. 6-O-methacryloyl-D-galactose (2) was also prepared as a water-soluble monomer. The mechanochemical solid-state copolymerization of 1 and 2 was carried out to obtain the water-soluble polymeric prodrug possessing the Bz4MC as a side chain. The mechanochemical copolymerization of 1 and 2 proceeded to completion, and the polymeric prodrug produced possessed a narrow molecular weight distribution. Three kinds of polymeric prodrugs, whose compositions were different from one another, were hydrolyzed in vitro. The hydrolysis of these polymeric prodrugs proceeded to completion. The rate constants of hydrolysis decreased with increasing the mole fraction of 1 in polymeric prodrug. It was sugg...

On the basis of the benz[d]indolo[2,3-g]azecine derivative 1 (LE300), structure-activity relations were investigated in order to identify the pharmacophore in this new class of ligands. Various structural modifications were performed and the inhibitory activities at human cloned D 1 , D 2L , and D 5 receptors were measured by using a simple fluorescence microplate reader based calcium assay. Subsequently, the affinities of active compounds were estimated by radioligand binding experiments, Deleting one of the aromatic rings as well as replacing it by a phenyl moiety abolishes the inhibitory activities almost completely. Contraction of the 10-membered central ring decreases them significantly. The replacement of indole by thiophene or N-methylpyrrole reduces the inhibitory activity, whereas replacing the indole by benzene increases it. Finally, the hydroxylated dibenz[d,g]azecine derivative 11d (LE404) was found to be more active than the lead 1 in the functional calcium assay as well ...

4-Amino-5-arylmethylidene-3-phenyl-pyridazin-6-ones 7 have been synthesized and reacted with selected nucleophile reagents such as phenyl hydrazine, semicarbazide, semithiocarbazide, cyanoacetohydrazide, 2-aminothiophenol, and 2-phenylenediamine in ethanol triethyl-amine solution. An unexpected 1-phenyl-3-arylaziridene 10, 3-aryl-5-oxo(thio)-1,2,4-triazole 21, 4-amino-3-aryl-6-hydroxy-pridazine 27, 2-arylbenzothiazole 30a-c, and 2-arylbenzimidazole 30d-f have been obtained, respectively. Also, 2-aminothiophenol and 2-phenylenediamine were reacted with N-phenylmethylidene- 2-cyanoacetohydrazide 2, affording the new 1,4-benzodiazepine derivatives 35. Copyright Taylor & Francis LLC. https://www.lookchem.com/CASDataBase_1019-85-8.htm

A method of alcohol-assisted copper-catalyzed highly selective deacetylative α-arylation of β-keto esters and amides has been demonstrated, which illustrated an efficient example of achieving α-aryl esters and amides. From the synthetic point of view, this arylation protocol is general and practical, representing a simple way to produce α-arylated carbonyl compounds from basic starting materials at low cost. https://www.lookchem.com/CASDataBase_102-16-9.htm

A protocol to link alcohols with vinyl azides has been established through fluoro- or bromo-alkoxylation of vinyl azides to provide α-alkoxy-β-haloalkyl azides. A series of primary and secondary alcohols including natural products and their derivatives such as sugars and steroids were successfully anchored with vinyl azides. The as-prepared cyanine dye linked testosterones were capable of rapid cell membrane imaging in real time. https://www.lookchem.com/CASDataBase_450-95-3.htm

A readily available bisoxazolidine ligand was found to catalyze the asymmetric alkylation of aldehydes with Et 2 Zn and less reactive Me2Zn, providing high yields and ee's in both reactions. The bisoxazolidine-catalyzed alkylations and alkynylation of benzaldehyde show a positive nonlinear effect that cannot be accounted for by Kagan's ML n model. The chiral amplification originates from selective phase distribution favoring enrichment of the major enantiomer of the scalemic catalyst in solution. https://www.lookchem.com/CASDataBase_101219-68-5.htm