Dinuclear Rh(I) complex with 2,7-bis(diphenylphosphino)-1,8-naphthyridine: Synthesis,structure, and dynamic property

Reaction of [RhCl(cod)]₂ with 2,7-bis(diphenylphosphino)-1,8-naphthyridine (dpnapy) and 2,6-xylyl isocyanide (XylNC) in the presence of NH₄PF₆ afforded the dirhodium(I) complex, [Rh₂(μ-dpnapy)₂(XylNC)₄](PF₆)₂ (5), and similar procedures using [MCl₂(cod)] (M = Pt, Pd) resulted in the formation of [Pt₂(μ-dpnapy)₂(XylNC)₄](PF₆)₄ (6) and [Pd₂Cl₂(μ-dpnapy)₂(XylNC)₂](PF₆)₂ (7). Complexes 5–7 were characterized by elemental analysis, IR, UV–Vis, ¹H and ³¹P{¹H} NMR, and ESI mass spectroscopic techniques, to involve a small and rigid d⁸ {M₂(μ-dpnapy)₂} metallomacrocycle. Complex 5 readily incorporated a silver(I) ion into the macrocycle to afford [Rh₂Ag(μ-dpnapy)₂(XylNC)₄](PF₆)₃ (8) which was characterized by X-ray crystallography. The Ag(I) ion is trapped by two trans N atoms of dpnapy ligands, resulting in an asymmetric Rh–Ag⋯Rh structure, determined as a disordered model in the crystal structure, and however, in a CH₂Cl₂ solution, a dynamic interconversion of the two Ag-trapped sites was observed with low-temperature NMR studies, which was further supported by DFT molecular orbital calculations. When an acetonitrile solution of complex 5 was treated over a droplet of mercury(0), the polymeric compound formulated as {[Rh(μ-dpnapy)(XylNC)₂](PF₆)}_n (9) was isolated as yellow single crystals, which were revealed by X-ray crystallography to consist of C₆ helical rods along c axis with a pitch of 33.5 Å (rise of unit = 5.6 Å) and a diameter of 20.64 Å.     

Synthesis of fused derivatives of 1,8-naphthyridine

Reactions of aromatic aldehyde, 2-aminoprop-1-ene-1,1,3-tricarbonitrile and cyclic enhydrazinoketones led to the formation of N-substituted 5-aryl-2,4-diamino-6-oxo-5,6,7,8,9,10-hexahydrobenzo[b][1,8]- naphthyridine-3-carbonitriles     

2,7-Bis(1H-pyrrol-2-yl)ethynyl-1,8-naphthyridine: an ultrasensitive fluorescent probe for glucopyranoside

[structure: see text] A push-pull conjugated molecule, 2,7-bis(1H-pyrrol-2-yl)ethynyl-1,8-naphthyridine (BPN), has been designed to bind selectively with octyl glucopyranoside (OGU). The BPN/OGU quadruple hydrogen-bonding complex adopts a rigid BPN conformation in which the proton donor (d) and acceptor (a) relays (daad) are resonantly conjugated through the ethynyl bridge, inducing pi-electron delocalization, i.e., a charge transfer effect. The excellent photophysical properties make BPN a highly sensitive probe for monitoring glucopyranoside to a detection limit of approximately 100 pM.     

Synthesis and insecticidal activities of 1,8-naphthyridine derivatives

1,8-Naphthyridines (NAP) are biological important scaffolds in bioactive molecules design. By hybrid of NAP with neonicotinoid core structure, nine novel NAP derivatives were synthesized and subjected to insecticidal activities evaluation. Some of the compounds showed excellent insecticidal activity against cowpea aphids (Aphis craccivora) with LC₅₀ values ranging from 0.011 mmol/L to 0.067 mmol/L. The results indicated that 1,8- naphthyridine can be used as insecticidal structure for further modification.     

A luminescent rhenium(I) complex of 2,7-dimethyl-1,8-naphthyridine: synthesis,spectroscopy and X-ray crystal structure

2,7-Dimethyl-1,8-naphthyridine (L¹) reacts with pentacarbonylchlororhenium in toluene or chloroform to give the target complex fac-{ReCl(CO)₃(L¹)}. X-ray crystallographic data were obtained for fac-{ReCl(CO)₃(L¹)}. The structural and ¹H NMR data suggest that the ligand coordinates to the rhenium in a bidentate fashion in both solid and solution states. The complex was also found to be luminescent in both solution and solid states. The fluxionality of the ligand in solution causes ligand-centred emission to be observed in solution, whereas only ³MLCT emission was observed in the solid state. Although the complex was air-stable, the lability of L¹ was studied in ¹H NMR experiments where CD₃OD induced complete ligand dissociation over the course of 24 h, and also in reaction of fac-{ReCl(CO)₃(L¹)} with one equivalent of 2,2′-bipyridine in chloroform which resulted in quantitative ligand exchange. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

1,8-Naphthyridines. Part I. Synthesis of some trifluoromethyl-1,8-naphthyridine derivatives

The synthesis of some 2-amino-1,8-naphthyridine derivatives substituted in the 5- and/or 7-positions with trifluoromethyl is described along with their conversions to the corresponding 1,8-naphthyridin-2(1H)ones. A modified procedure for oxidizing electron-deficient heterocyclic compounds to their N-oxides is presented.     

Synthesis of new heterocyclic systems fused at pyrazolo[3,4-c]-2,7-naphthyridine core

Efficient syntheses of new heterocyclic systems comprising pyrimido[1',2':1,5]pyrazolo[3,4-c]-2,7-naphthyridine, pyrazolo[3,4-c][1,2,4]triazolo[3,4-a]-2,7-naphthyridine and pyrazolo[3,4-c]tetrazolo[5,1-a]-2,7-naphthyridine cores were performed in two simple steps. In the first step, pyrazole ring was fused at the 2-chloro-3-cyanopyridine moiety by treatment with hydrazine. In the second step, pyrimidine part was fused at the thus formed 3-aminopyrazole moiety by heterocyclization with acetylacetone.     

Tetraacylation of isobutene: first synthesis of 1,3,6,8-tetramethyl-2,7-naphthyridine

The tetxaacetylation of isobutene has been perfomed in AlCl₃/AcCl. Treatment of the crude reaction medium with liquid ammonia yields the title compound.     

Simple and efficient synthesis of 2,7-difunctionalized-1,8-naphthyridines

The syntheses in good yields of some new difunctionalized 1,8-naphthyridines 4, 6, 8 and 9 and a novel triethylene glycol ether-linked dinaphthyridine, 10a, along with the mononaphthyridine-linked ether alcohol 10b are described. An improved and milder method for the synthesis of 2,7-diamino-1,8-naphthyridine (14) is also reported.     

6H-anthra[1,9,8-c,d,e,f]-2,7-naphthyridine derivatives

5,7-Dinitro derivatives are formed in the nitration of 2H,10H-anthra[1,9,8-c,d,e,f]-2,7-naphthyridine-1,6,11-trione and its N,N'-dimethyl derivatives. 5,7-Dichloro- and 5,7-dibromoanthranaphthyridine-1,6,11-triones were obtained by reaction of 1,8-diamino-4,5-dihaloanthraquinones with diethyl malonate. Disubstituted anthranaphthyridine triones react with amines to give the corresponding 5,7-diaryl(alkyl)aminoanthranaphthyridine 1,6,11-triones.See [1] for communication I.Deceased.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1645–1648, December, 1976.     

2,7-二甲基-2,4,6-辛三烯二醛的合成研究

2,7-二甲基-2,4,6-辛三烯-1,8-二醛1(2,7-dimethylocta-2,4,6-triene-1,8-dial)一直以来都被认为是合成类胡萝卜素的关键中间体之一,国外对它的合成研究起步较早,国内在2005年之前鲜有报道.     

6H-anthra[1,9,8-c,d,e,f]-2,7-naphthyridine derivatives

Derivatives of a new heterocyclic system- 6H-anthra[1,9,8-c,d,e,f]-2,7-naphthyridine-were obtained by condensation of 1,8-diaminoanthraquinone with malonic ester, acetoacetic ester, and benzoylacetic ester.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 679–681, May, 1974.     

Synthesis of furo[2,3-c]-2,7-naphthyridine derivatives via domino heterocyclization reaction

2-Amino-4-cyanomethyl-6-dialkylamino-3,5-pyridinedicarbonitriles were found to react with substituted oxiranes yielding 5,6-diamino-8-dialkylamino-1,2-dihydrofuro[2,3-c]-2,7-naphthyridine-9-carbonitriles. The oxirane ring was shown to be opened selectively from the unsubstituted side and further cyclization occurred with participation of 3-CN, but not 5-CN of the starting pyridines. The furonaphthyridines obtained were converted into 2-dialkylamino-5-methyl-9,10-dihydro-4H-furo[2,3-c]pyrimido[4,5,6-ij]-2,7-naphthyridine-1-carbonitriles and 2-dialkylamino-5,6,9,10-tetrahydro-4H-spiro{furo[2,3-c]pyrimido[4,5,6-ij]-2,7-naphthyridine-5,1′-cyclohexane}-1-carbonitriles by treatment with acetic anhydride and cyclohexanone, respectively. The structure of prepared compounds was confirmed unambiguously by X-ray crystallographic study.     

Synthesis of 1,8-naphthyridine derivatives. Potential antihypertensive agents. 1

Reaction of substituted 7-chloro-1,8-naphthyridines with N-carbethoxypiperazine gave in good yields the corresponding 7-(4-carbethoxypiperazin-1-yl)-1,8-naphthyridines V as potential antihypertensive agents.     

Pd-catalyzed amidation of 2-chloro- and 2,7-dichloro-1,8-naphthyridines

[reactions: see text] The catalytic amidation between 2-chloro- and 2,7-dichloro-1,8-naphthyridines and primary amides bearing functional groups is reported. When Pd(OAc)2, xantphos, and K2CO3 are used, it is possible to obtain symmetric as well as nonsymmetric 2,7-diamido-1,8-naphthyridines in 50-90% yield with good functional-group tolerance. Monoamidation of 2,7-dichloro-1,8-naphthyridine using 0.9 equiv of the amide proceeded with good selectivity compared to the formation of the diamide, but as a result of the difficult isolation of the product, isolated yields were poor to moderate (22-42%).     

2-(芘-1-基)-1,8-萘啶的合成、理论计算及超快三阶非线性光学响应

合成了一个供体-受体(D-A)型含芘萘啶衍生物2-(芘-1-基)-1,8-萘啶(PN)。 通过核磁共振波谱(NMR)、傅里叶变换红外光谱(FTIR)、液-质联用仪(LC-MS)表征了其结构。 通过电子光谱和Z-扫描技术方法分别研究了化合物PN的线性光学性质和三阶非线性光学吸收,采用综合热分析方法测定了它的热稳定性。 结果表明,在532 nm、180 fs条件下,PN的三阶非线性吸收行为为反饱和吸收,其吸收系数为β=9.0×10^-14 m/W,显示出超快三阶非线性光学响应。 运用密度泛函理论方法计算了分子轨道能量、极化率和超极化率,结果表明电子转移能够在分子内部进行。 2-(芘-1-基)-1,8-萘啶的紫外光谱在450 nm以上无吸收,在非线性光学吸收、激光防护、吸收型光开关或双稳器件等方面可作备选材料。     

Synthesis of a novel tripodal receptor based on 1,8-naphthyridine derivatives

<正>A novel tripodal receptor,1,3,5-tri((5,7-dimethyl-1,8-naphthyridin-2-yl-amino)methyl)-2,4,6-triethylbenzene(1) was synthesized from starting materials 2,6-diamino-pyridine(2) and 1,3,5-triethylbenzene(4) by three steps with an overall yield of 25%,and characterized by ESI-MS,FT-IR and ~1H NMR spectra.Additionally,its absorption and emission spectra were investigated.