Synthesis of amine, halide, and pyridinium terminated 2-alkyl-p-tert-butylcalix[4]arenes

The synthesis of calix[4]arenes with functional groups tethered to a single methylene bridge has been explored. Mono-lithiated calix[4]arenes react with 1,ω-bromochloroalkanes to give 2-(ω-chloroalkyl)-calix[4]arenes, which function as key intermediates in the synthesis of a variety of tether-functionalized calix[4]arenes. Subsequent reactivity of these chloroalkyl species has allowed for successful synthesis of 2-(ω-iodoalkyl)-calix[4]arenes, 2-(ω-pyridiniumalkyl)-calix[4]arenes, and 2-(ω-aminoalkyl)-calix[4]arenes. This latter group of amine-terminated calix[4]arenes are especially significant as they may serve as useful entries to a wide range of subsequent chemistry, including metal coordination or attachment to a solid support. Both alkyl and aryl amines have been incorporated at the end of the tether, and a 2,6-diisopropylaniline derivative has been analyzed by X-ray diffraction.     

Synthesis, X-ray crystallography, and computational analysis of 1-azafenestranes

The tandem [4+2]/[3+2] cycloaddition of nitroalkenes has been employed in the synthesis of 1-azafenestranes, molecules of theoretical interest because of planarizing distortion of their central carbon atoms. The synthesis of c,c,c,c-[5.5.5.5]-1-azafenestrane was completed in good yield from a substituted nitrocyclopentene, and its borane adduct was analyzed through X-ray crystallography, which showed a moderate distortion from ideal tetrahedral geometry. The syntheses of two members of the [4.5.5.5] family of 1-azafenestranes are also reported, including one with a trans fusion at a bicyclic ring junction which brings about considerable planarization of one of the central angles (16.8 degrees deviation from tetrahedral geometry). While investigating the [4.5.5.5]-1-azafenestranes, a novel dyotropic rearrangement that converts nitroso acetals into tetracyclic aminals was discovered. Through conformational analysis, a means to prevent this molecular reorganization was formulated and realized experimentally with the use of a bulky vinyl ether in the key [4+2] cycloaddition reaction. Finally, DFT calculations on relative strain energy for the 1-azafenestranes, as well as their predicted central angles, are disclosed.     

Multistep, microwave assisted, solvent free synthesis and antibacterial activity of 6-substituted-2,3,4-trihydropyrimido[1,2-c]9,10,11,12-tetrahydrobenzo[b]thieno[3,2-e]pyrimidines

A novel, efficient, microwave assisted route for the synthesis of 6-substituted-2,3,4-trihydropyrimido[1,2-c]-9,10,11,12-tetrahydrobenzo[b]thieno[3,2-e]pyrimidines in good yields has been developed. The intermediates, 2-substituted-4-[3-hydroxy(propyl-1-amino)]5,6,7,8-tetrahydrobenzo[b]thieno[2,3-d]pyrimidines were obtained by irradiating 2-substituted-4-chloro-5,6,7,8-tetrahydrobenzo[b]thieno[2,3-d]pyrimidines with 1-amino-propanol under basic conditions in a microwave oven. 4-Chlorothieno[2,3-d]pyrimidines were synthesized by microwave irradiation of equimolar mixture of 4-hydroxythieno[2,3-d]pyrimidines and phosphorus oxychloride. The final compounds were screened for antibacterial activity by Kirby Bauer's method using amicacin as the standard against various gram positive and gram negative bacteria. All the compounds showed antibacterial activity comparable with the standard.     

[4]Cyclo-N-ethyl-2,7-carbazole: Synthesis,Structural, Electronic and Charge Transport Properties

Nanorings, which are macrocycles possessing radially directed π-orbitals have shown fantastic development in the last ten years. Unravelling their unusual electronic properties has been one of the driving forces of this research field. However, and despite promising properties, their incorporation in organic electronic devices remains very scarce. In this work, we aim to contribute to bridge the gap between organic electronics and nanorings by reporting the synthesis, the structural and electronic properties and the incorporation in an organic field-effect transistor (OFET) of a cyclic tetracarbazole, namely [4]cyclo-N-ethyl-2,7-carbazole ( [4]C-Et-Cbz ). The structural, photophysical and electrochemical properties have been compared to those of structurally related analogues [4]cyclo-9,9-diethyl-2,7-fluorene [4]C-diEt-F (with carbon bridges) and [8]-cycloparaphenylene [8]CPP (without any bridge) in order to shed light on the impact of the bridging in nanorings. This work shows that nanorings can be used as an active layer in an OFET and provides a first benchmark in term of OFET characteristics for this type of molecules.     

In situ generation of vinyl allenes and its applications to one-pot assembly of cyclohexene, cyclooctadiene, 3,7-nonadienone, and bicyclo[6.4.0]dodecene derivatives with palladium-catalyzed multicomponent reactions

A novel tandem Pd-catalyzed cross-coupling and [4 + 4] cycloaddition sequence allows the rapid synthesis of eight-membered carbocycles starting from alpha-bromovinyl arenes and propargyl bromides in one reaction vessel. It is noteworthy that four components are assembled into one molecule via this procedure. In contrast to alpha-bromovinyl arenes, alpha-bromovinyl alkanes afforded tandem cross-coupling and homo [4 + 2] cycloaddition products. Subjecting an equimolar mixture of alpha-bromostyrene and 2-bromo-1-octene to propargyl bromides furnished the tandem Pd-catalyzed cross-coupling and hetero [4 + 2] cycloaddition product. Exposure of equimolar mixtures of alpha-bromovinyl arenes to allenylindium resulted in tandem a Pd-catalyzed cross-coupling and hetero [4 + 4] cycloaddition products. Synthesis of vinylallene from the reaction of vinyl triflate with allenylindium followed by Pd-catalyzed carbon monoxide insertion reaction gave the corresponding 3,7-nonadienone product via tandem Pd-catalyzed cross-coupling and [4 + 4 + 1] annulation. Tandem Pd-catalyzed cross-coupling, [4 + 4] cycloaddition, and [4 + 2] cycloaddition provided the rapid synthesis of bicyclo[6.4.0]dodecene derivatives starting from alpha-bromovinyl arenes, propargyl bromides, and dienophiles in one operation, in which five components were integrated into one molecule.     

Synthesis of a 2, 4, 8-trisubstituted pyrimidino[5, 4-d]pyrimidine library via sequential SNAr reactions on solid-phase

A solid-phase synthesis of 2, 4, 8-substituted pyrimidino[5, 4-d]pyrimidines involving three controlled S(N)Ar reactions has been developed. Exploration of different heterocyclic starting materials and resin-bound intermediates is highlighted. The preferred method starts with the treatment of resin-bound anilines with 2, 4, 8-trichloropyrimidino[5, 4-d]pyrimidine. This intermediate is subsequently treated with various amines in two steps to yield the final products. The scope of each diversity step was determined and a library of 16, 000 compounds was synthesized.     

An efficient synthesis of novel benzo[b]pyrido[3',2':4,5] thieno[2,3-e][1,6]naphthy-ridine-8-ones

An efficient method for the synthesis of novel benzo[b]pyrido[3',2':4,5] thieno[2,3-e][1,6] naphthyridine-8-one derivatives has been developed using a Pictet-Spengler reaction between 4-(3-aminothieno[2,3-b]pyridin-2-yl)quinoline-2-ones, which could be obtained from the alkylation of 4-bromomethylquinoline-2-ones with 3-cyanopyridine-2-thione followed by a Thorpe-Ziegler isomerization, and aromatic aldehydes under p-TsOH as catalysis in good yields.     

Preparation, structure, and anion sensing properties of 1,n-diaza[n]ferrocenophanes

The synthesis of structurally new types of azaferrocenophanes is reported in this note: 4, which comprises a 1,2-fused azaheterocycle to a 1,3-diaza[3]ferrocenophane framework; 1,3-diaza[3]ferrocenophanes 5 and 7, which can be considered as a 1,1'-ferrocenylene N,N'-guanidine or urea, respectively; and 1,3,6,8-tetraza[8]ferrocenophanes 9 and 10, bearing two ureido moieties in the ansa-bridge. These compounds were prepared directly from 1,1'-bis(isocyanato)ferrocene 1 and thoroughly characterized by spectroscopic means. Tetraza[8]ferrocenophanes 9 and 10 show spectral and electrochemical anion-sensing action: they display a selective downfield shift of the urea protons and a cathodic shift of the ferrocene/ferrocinium redox couple with dihydrogenphosphate and fluoride anions. The crystal structure of compound 4 has been determined by single-crystal X-ray methods.     

A facial microwave-assisted synthesis, spectroscopic characterization and preliminary complexation studies of calix[4]pyrroles containing the hydroxamic-acid moiety

The synthesis, spectroscopic characterization and preliminary complexation properties of functionalized calix[4]pyrroles are described. To date, two generalized preparative approaches have been pursued (i) modifying the basic pyrrole-plus-ketone synthesis of calix[4]pyrrole by using microwave irradiation protocol, (ii) the basic meso-tetra(methyl) meso-tetra(p-nitrophenyl) calix[4]pyrrole skeleton was functionalized to give hydroxamic acids, especially in the meso-position of the macrocycles. The structures of novel calix[4]pyrrole hydroxamic acid derivatives were confirmed on the basis of various physico-chemical techniques such as elemental analysis, FT-IR, ¹H NMR and FAB-Mass. The results of preliminary studies on the extraction of vanadium (V) with the host calix[4]pyrrole hydroxamic acids were elucidated by significant examination of UV–Vis spectroscopy and ICP-AES. Single crystal structure of basic meso-tetra(methyl) meso-tetra (p-nitro phenyl) calix[4]pyrrole moiety has also been reported.     

Synthesis of a polypseudorotaxane, polyrotaxane, and polycatenane using ‘click’ chemistry

The synthesis of a polypseudorotaxane, polyrotaxane, and polycatenane containing the electron-deficient cyclophane cyclobis(paraquat-p-phenylene) (CBPQT⁴⁺) subunit in the side chain is described. These interlocked supramolecular polymers have been prepared from an azide-functionalized polystyrene derivative and an acetylene-functionalized [2]rotaxane, [2]catenane and their parent tetracationic cyclophane via Cu(I)-catalyzed 1,3 dipolar cycloadditions (‘click chemistry’). The synthesis and characterization of the polymers and intermediates has been described using IR, ¹H NMR, UV spectroscopies, and voltammetry. We have shown that the CBPQT⁴⁺ unit of the side chain polystyrene derivative has the ability to reversibly undergo complexation with a complementary dialkoxynaphthalene derivative.     

From propargylic biscarbonate to diaryl[n]dendralenes

An efficient cross-coupling reaction using a low cost carbon-supported palladium (Pd/C) catalyst for the synthesis of cross-conjugated compounds, diaryl[n]dendralenes, has been developed. The reaction of a propargylic biscarbonate with phenylboronic acid using Pd/C and phosphine ligand (S-Phos) gave 2,3-diphenyl[2]dendralene in high yield. We found that Pd/C was an effective catalyst for the synthesis of dialyl[n]dendralenes. The synthesis of various dendralenes was successfully achieved under the optimized conditions, giving dialyl [2] and [4] dendralenes in good yields.     

Synthesis, Characterisation and UV-Vis Properties of Azocalix[4]crowns

This article describes the synthesis, structure andUV properties of azocalixcrowns in which the photoresponsivetrans-cis azo benzene unit has been introduced in the glycolicchains of the calix[4]crowns. The synthesis proceeded via the selective-1,3O-dialkylation of calix[4]arene with glycolic chains terminated bynitrophenyl residues. After reduction of thenitro groups into amino functions,intramolecular oxidative coupling produced thecapping of the calixarene. Thesynthetic approaches and the cis-transstructure of these new ligandsare discussed and full details on synthesesand structural data are given. Apreliminary example of cesium complexation byone of the ligands is proposed.     

Ruthenium(II) polypyridyl complexes: potential precursors, metalloligands, and topo II inhibitors

Neutral and cationic mononuclear complexes containing both group 15 and polypyridyl ligands [Ru(kappa3-tptz)(PPh3)Cl2] [1; tptz=2,4,6-tris(2-pyridyl)-1,3,5-triazine], [Ru(kappa3-tptz)(kappa2-dppm)Cl]BF4 [2; dppm=bis(diphenylphosphino)methane], [Ru(kappa3-tptz)(PPh3)(pa)]Cl (3; pa=phenylalanine), [Ru(kappa3-tptz)(PPh3)(dtc)]Cl (4; dtc=diethyldithiocarbamate), [Ru(kappa3-tptz)(PPh3)(SCN)2] (5) and [Ru(kappa3-tptz)(PPh3)(N3)2] (6) have been synthesized. Complex 1 has been used as a metalloligand in the synthesis of homo- and heterodinuclear complexes [Cl2(PPh3)Ru(micro-tptz)Ru(eta6-C6H6)Cl]BF4 (7), [Cl2(PPh3)Ru(mu-tptz)Ru(eta6-C10H14)Cl]PF6 (8), and [Cl2(PPh3)Ru(micro-tptz)Rh(eta5-C5Me5)Cl]BF4 (9). Complexes 7-9 present examples of homo- and heterodinuclear complexes in which a typical organometallic moiety [(eta6-C6H6)RuCl]+, [(eta6-C10H14)RuCl]+, or [(eta5-C5Me5)RhCl]+ is bonded to a ruthenium(II) polypyridine moiety. The complexes have been fully characterized by elemental analyses, fast-atom-bombardment mass spectroscopy, NMR (1H and 31P), and electronic spectral studies. Molecular structures of 1-3, 8, and 9 have been determined by single-crystal X-ray diffraction analyses. Complex 1 functions as a good precursor in the synthesis of other ruthenium(II) complexes and as a metalloligand. All of the complexes under study exhibit inhibitory effects on the Topoisomerase II-DNA activity of filarial parasite Setaria cervi and beta-hematin/hemozoin formation in the presence of Plasmodium yoelii lysate.     

The clusters [Ma(ECp*)b] (M=Pd, Pt; E=Al, Ga, In): structures, fluxionality, and ligand exchange reactions

The synthesis and structural characterization of the novel homoleptic cluster complexes [Pd2(GaCp*)2(mu2-GaCp*)3] (1c), [Pd3(GaCp*)4(mu2-GaCp*)4] (2b) and [Pd3(AlCp*)2(mu2-AlCp*)2(mu3-AlCp*)2] (3) (Cp*=C5Me5) are presented. Furthermore, ligand exchange reactions of these cluster complexes are explored. In contrast to the electronically and sterically saturated complexes [M(ECp*)4] (M=Ni, Pd, Pt), the new unsaturated analogues [M(a)(ER)b] (E=Al, Ga, In) react with a variety of typical ligands (Cp*Al, CO, phosphines, isonitriles) to give new di- and tri-substituted compounds like [Pt2(GaCp*)2(mu2-AlCp*)3] (1d), [PdPt(GaCp*)(PPh3)(mu2-GaCp*)3] (4b), or [Pd3(PPh3)3(mu2-InCp*)(mu3-InCp*)2] (8). The trends of the reactivity of [M(a)(ER)b] as well as their fluxional behavior in solution has been elucidated by NMR spectroscopy, resulting in a mechanistic rationale for the ligand exchange reactions as well as the fluxional processes.     

Synthesis of dithieno[2,3-b:4',3'-d]siloles and their selective bromination

The efficient synthesis of novel unsymmetrical dithienosiloles, 7,7-dimethyl-4,6-di(trimethylsilyl)-dithieno[2,3-b:4',3'-d]silole (1) and 7,7-dimethyl-2,4,6-tri(trimethylsilyl)-dithieno[2,3-b:4',3'-d]silole (2) has been developed by intramolecular silole formation with 4,4'-dibromo-2,2',5,5'-tetrakis(trimethylsilyl)-[3,3']bithienyl (3) as the starting material in the presence of t-BuLi. Upon treatment with N-bromosuccinimide (NBS) under controlled conditions, dithieno[2,3-b:4',3'-d]silole was selectively brominated to produce mono-, di-, and tribrominated dithieno[2,3-b:4',3'-d]siloles in good yields. The crystal structures of the title compounds are described.     

Ergebnisse der Verfahrensforschung,I. Synthese von o-{(+)-D-2-[4-(4-(Trifluormethyl)phenoxy)phenoxy]propionyl}-aceton-oxim

Results of process Research I. Synthesis of O-{(+)-D-2-[4-(4-(triluoromethyl)phenoxy)phenoxy]propionyl}-acetone oxime Efficient and simple procedures for the preparation of O-{L-[(sulfonyl)oxy]-propionyl}-oxime derivatives 7b-e have been developed. The alleviation of 4-[4-(trifluoromethyl)phenoxy]phenol ( 11 ) with 7d , the final step of a technical synthesis of 1 , has been studied in detail.     

钼铁硫簇合物的合成、结构和性质研究

本文综合报导[(C_4H_9)_4N]_3[Fe(MoS_4)_2O],[(C_2H_5)_4N]_3[Fe(MoS_4)_2O_2],[(C_2H_5)_4N]_3 [Fe(MoS_4)_2O_2]·CH_3CH,[(C_4H_9)_4M]_2[Mo_2S_6O_2],[(C_2H_5)_4N]_3{[(SCH_2CH_2S)MoS_3]_2Fe}和[(C_2H_5)_4N]_4[Fe_6S_9(SCH_2CH_2OH)Cl]六种簇合物的合成、结构和性质研究。在Nicolct R_3 system四园单晶衍射仪上,用CuK_a(MoK_a)辐射收集数据,用SHELXTL程序,重原子法解出这些簇合物的晶体结构。用红外光谱,紫外可见光谱和穆斯堡尔谱对簇合物进行了物理性质的测定。同时在还原剂KBH_4存在下,对簇合物的催化乙炔还原为乙烯的活性也进行了测定。并结合量子化学计算探讨了簇合物的电子结构和性能之间的关系。     

Rhodium-Catalyzed Enantioselective Synthesis,Structures, and Properties of Single and Double Azahelicene-Like Molecules

The enantioselective synthesis of aza[6] and [7]helicene-like molecules have been achieved by the cationic rhodium(I)/axially chiral biaryl bisphosphine complex-catalyzed intramolecular [2+2+2] cycloaddition of cyanodiynes. This protocol was successfully applied to the diastereo- and enantioselective synthesis of an S-shaped double aza[6]helicene-like molecule with a high ee value of 89 %. Although no epimerization and racemization were observed in the double carbo[6]helicene-like molecule at 80 °C, epimerization and racemization of the double aza[6]helicene-like molecule proceeded at 80 °C. This double aza[6]helicene-like molecule showed good fluorescent quantum yields and chiroptical responses under both neutral and acidic conditions.     

Preparation of bicyclo[3.2.0]heptane-2-endo,7-endo-diols: 1,3-diols with a chiral rigid backbone

The easily available bicyclo[3.2.0]hept-3-en-6-ones (1a-f) have been converted into the corresponding bicyclo[3.2.0]heptane-2-endo,7-endo-diols (4a-f) in an efficient and stereoselective fashion. This preparation opens a route to a family of 1,3-diols with a chiral rigid backbone, potentially suitable as nonracemic precursors for bidentate ligands in asymmetric synthesis.     

Facile synthesis of oligophenylene-substituted calix[4]arenes and their enhanced binding properties

[reaction: see text] A facile and efficient protocol for the synthesis of oligophenylene OPP(n)-substituted calix[4]arenes (with n up to 4) via iodo-substituted oligoarylcalix[4]arenes has been developed. The cooperation effect of the proximate fluoroionophores in hexylsulfanyl end-capped OPP(n)-substituted calix[4]arene assemblies leads to metal ion binding enhancement.