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1.
Herein, an electrochemically driven NiH-catalyzed reductive coupling of alkyl halides and alkyl alkenes for the construction of Csp3−Csp3 bonds is firstly reported. Notably, alkyl halides serve dual function as coupling substrates and as hydrogen sources to generate NiH species under electrochemical conditions. The tunable nature of this reaction is realized by introducing an intramolecular coordinating group to the substrate, where the product can be easily adjusted to give the desired branched products. The method proceeds under mild conditions, exhibits a broad substrate scope, and affords moderate to excellent yields with over 70 examples, including late-stage modification of natural products and drug derivatives. Mechanistic insights offer evidence for an electrochemically driven coupling process. The sp3-carbon-halogen bonds can be activated through single electron transfer (SET) by the nickel catalyst in its low valence state, generated by cathodic reduction, and the generation of NiH species from alkyl halides is pivotal to this transformation.  相似文献   

2.
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.  相似文献   

3.
4.
Owing to the particular affinity toward metal ion and changeable dentation, dialkyldithiophosphates are commonly used ligands in preparation of the transition metal complexes with variable structures1. For instances relevant to this work, the IIB metal complexes defined crystallographically so far have provided the examples as follows2-12 (Scheme 1). Scheme 1 The frameworks of IIB metal complexes of dialkyldithiophosphate MMMMMMMMMM a b c d …  相似文献   

5.
The synthesis of 3‐alkyl and arylapomorphines 1820 has been accomplished by using the Suzuki–Miyaura cross‐coupling reaction of vinyl‐ and allylhalide morphinanedienes or arylhalide apocodeines and arylboronic acids.  相似文献   

6.
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 (ΔGads) was more negative than their standard free energy of micellization (ΔGmic). 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.  相似文献   

7.
Highly enantioselective hydrogenation of β‐alkyl and β‐(ω‐chloroalkyl) substituted β‐keto esters was achieved with Ru catalysts based on chiral diphosphines in EtOH at 50°C under 50‐bar initial hydrogen pressure, affording the corresponding β‐hydroxy esters in >98% ee.  相似文献   

8.
By dropwise adding thio ligands to concentrated aqueous solutions of Cd(ClO4)2·6H2O, polymeric complexes, Cd(II) O, O'‐dipropyldithiophosphate (1), O, O'‐dibutyl‐dithiophosphate (2), O, O'‐diisopropyl‐dithiophosphate (3) and O, O'‐diisobutyl‐dithiophosphate (4) were obtained. The structure of 4 was determined by X‐ray diffraction analysis, showing that the metal ion sits in distorted tetrahedral sulphur coordination sphere and that the eight‐membered bimetallic rings take the twist chair and boat conformations, alternately. Based on facts that the S(1)—Cd bond length [0.25099(12) nm] is shorter than the other S—Cd bond length [0.25399(12)—0.25701(18) nm] and that the S(1)‐involving angles [113.45(4)°—118.43(5)°] are systematically larger than the normal angles of a tetrahedron, the ligands are hypothesized to be erratically functionalized to Cd(II). To certify the steric nonequivalence of ligands, the compounds were investigated by solid 13C, 31P and 113Cd NMR spectroscopy.  相似文献   

9.
Densities and viscosities have been determined for binary mixtures of isopropyl acetate or isobutyl acetate with o-xylene, m-xylene, p-xylene and ethyl benzene at (303.15 and 313.15) K for the entire composition range. The excess molar volumes and deviations in viscosity have been calculated from the experimental values. The variations of these parameters, with composition of the mixtures and temperature, have been discussed in terms of molecular interactions occurring in these mixtures. Further, the viscosities of these binary mixtures were calculated theoretically from their corresponding pure component data by using empirical relations, and the results were compared with the experimental findings.  相似文献   

10.

A series of novel 2-(thymin-1′-ylmethoxy)ethyl alkyl sulfides have been synthesized in three steps from thymine. They have been oxidized into sulfoxide and sulfone derivatives by means of NaIO 4 and H 2 O 2 30%/diethyl azodicarboxylate (DEAD), respectively, in high yields. All products were characterized by 1 H NMR and IR spectra and elemental analyses. The preliminary bioassay indicates that the compound 6g exhibited potential antitumor activity.  相似文献   

11.
Sincethediscoveryoftristableswitching'andthesubsequentidentificationofmesomorphicphasesinMHPOBC2'3I,thesynthesisofnewliquidcrystalshaveattractedmuchattention.Theliquidcrystals,incorporatingtheSatom,suchasthioester4,sulfoxides5andsulfone',havebeenstudied.PrelindnarydatasuggestedthatthisstrUcturalchangefavoredtheformationofsmecticphases.WefirstintroducedsuIfonateintoliquidcrystalsandplannedthesynthesisofthiscategoryinordertostudyitsproperties.Wepresentherethesynthesisandcharacterizationsbase…  相似文献   

12.
The preparation of monolayers on silicon surface is of growing interest for potential applications in biosensor or semiconductor technology. Different experimental technique can be used to investigate the alkyl modified Si(III) surfaces1-4, such as X-ray photoelectron spectroscopy (XPS), Fourier transform infrared absorption spectra(FTIR), scanning electron microscopy (SEM), Auger electron spectroscopy (AES), scanning tunneling microscope (STM), and so on. These experimental results…  相似文献   

13.
The results of this study show that disilathiane is an effective mediator in the synthesis of alkyl aryl sulfides with disulfides and alkyl carboxylates. Mechanistic studies suggest that disilathiane promotes cleavage of the sulfur–sulfur bond of disulfides to generate thiosilane as a key intermediate. Diselenides were also applicable to this transformation to produce the corresponding selenides.  相似文献   

14.
Intruduction  Thedevelopmentofnucleosideprodrugscapableofundergoingintracellularactivationtothecorrespondingnucleotidehasbecomeanareaofintenseinterest.1Sever alpurineandpyrimidinebasesandnucleosideanalogsareimportantweaponsintheanticancerandantiviralc…  相似文献   

15.
Novel alkyl thiophosphoramidate derivatives of nucleosde analogues(5) have been prepared by phosphochloridothioate chemistry.O-Isopropyl 2‘,3‘-O-isopropylidene uridine-5‘-yl N-thiophosphoryl threonine and serine methyl esters(5a and 5b )underwent the intramolecular catalyzed hydrolysis reaction.  相似文献   

16.
Qing Dai  Ruyu Chen 《合成通讯》2013,43(19):3341-3347
A series of alkyl hydrogen α-(benzyloxycarbonylamino)benzylphosphonates are prepared from benzyl carbamate, substituted benzaldehydes and alkoxydichlorophosphine in acetyl chloride and subsequent hydrolysis. Compared with the previous methods, the reaction avoids producing the corresponding diesters and thus improves the yields of the products.  相似文献   

17.
TheC-ph0sphorylatedcarbamatederivativeshavereceivedspecialattentionbecauseoftheirpesticidalactivity.Wewereinterestedinfindingafacilemethodf0rthesynthesis0fthetitlec0mpounds.Therehavebeens0mereportsonthesynthesis0f(dialkylph0sphono)arylmethylcarbamates',whichwerepreparedbytreatingdialkylis0cyanat0phosphitewithsubstitutedbenzaldehydefoll0wedbyhydr0lysiswithwater.However,thismeth0dhassomelimitationsduetol0wyield,anddialkylisocyanatophosphiteisnoteasytoprepare.Inthestudy0fthenucIeophilicadditionr…  相似文献   

18.
A simple, facile, and convenient practical method for the one-pot synthesis of pharmaceutically interesting 5,5`-(1,4-phenylenebis-(methanylylidene))bis-thiohydantoins via a three-component condensation reaction of terephthalaldehyde, α-amino acids and isothiocyanates had been developed. The S-alkylated derivatives 6a and 6b were obtained by the alkylation of the bis-thiohydantoins 4a with methyl iodide and/or benzyl chloride in a basic media. The molecular structures of the synthesized compounds were confirmed by their elemental analyses and spectral data (IR, 1H, 13C NMR and MS). The assignment of more stable Z- or E-isomers as the major form of 4a, 6a, and 8a was investigated by DFT calculations at B3LYP/6-31+G* level. Some of the prepared compounds were screened for their in-vitro antimicrobial activity. Compounds 4a, 6 b, 8 b and 8c exhibited low antibacterial activity against gram-positive bacteria Bacillus cereus. (5Z,5′Z)-5,5′-(1,4-Phenylenebis(methanylylidene))bis(3-benzyl-2-thioxoimidazolidin-4-one) (4b) exhibited good fungicidal activity against Fusarium oxysporum.  相似文献   

19.
SynthesisandAmphiphilicCharacteristicsof 8-HydroxyquinolinewithAlkylChainSynthesisandAmphiphilicCharacteristicsof8-Hydroxyqui...  相似文献   

20.
Acetylation of 1H‐2‐(α‐hydroxyalkyl/aryl)benzimidazoles 2 with Ac2O results in the regiospecific formation of O‐acetoxy derivative 3, which on alkylation with alkylating agents in nonaqueous media under phase‐transfer catalytic conditions affords N‐alkyl derivatives 4. The latter, on hydrolysis in an aqueous basic medium, results in the title compounds 5 in good yields in high purity. Alternatively, 5 can also be obtained by reduction of 1‐substituted‐2‐acetyl/benzoylbenzimidazoles 8 using NaBH4.  相似文献   

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