Synthesis and photoluminescence properties of BF2 complexes with 1,3-diketone ligands

BF₂ complexes with 1,3-diketone ligands were synthesized, and their optical and electrochemical properties were studied. The colors of the complexes varied depending on the structures of the 1,3-diketone ligands. The absorption and emission maxima of the complexes with 1,3-diaryl-1,3-diketone ligands were considerably red shifted as compared to those of the complexes with 1-aryl-3-trifluoromethyl-1,3-diketone ligands, suggesting an extended π-conjugation of the 1,3-diaryl-1,3-diketone moieties. The molar absorption coefficients and quantum yields of the complexes with 1,3-diaryl-1,3-diketone ligands were larger than those of the complexes with 1-aryl-3-trifluoromethyl-1,3-diketone ligands. Cyclic voltammetry measurements revealed that the reduction potentials of the BF₂ complexes were higher than those of the free ligands. These complexes exhibited various emission colors in the solid states due to the intermolecular interactions.     

Catalyst- and halogen-free regioselective Friedel-Crafts α-ketoacylations

Fast, efficient and green! Highly regioselective and efficient catalyst- and halogen-free Friedel-Crafts α-ketoacylation reactions leading to heterocycles functionalized with a very versatile 1,3-diketone moiety are described. The reactions rely on microwave-assisted domino Wolff rearrangement/Friedel-Crafts sequences from 2-diazo-1,3-diketones via transient, highly reactive α-keto ketene intermediates.     

Synthesis and photophysical properties of europium pentafluorinated β-diketonate complexes

Research on Chemical Intermediates - Two pentafluorinated β-diketone ligands, 4,4,5,5,5-pentafluoro-1-(4-methoxyphenyl)pentane-1,3-dione (PFMP) and 4,4,5,5,5-pentafluoro-1-(4-dimethyl...     

The enhancement of luminescent properties of Tb3+ complexes with tetra-1,3-diketone ligands promoted by the tetrathiacalix[4]arene scaffold

This is the first report on the synthesis and characterization of tetra-1,3-diketone derivatives of tetrthia- and calix[4]arenes substituted by acetylacetonyl or dipivaloylmethanyl moieties at the upper rim and bearing hydroxyl groups at the lower rim as ligands for Tb³⁺ complexes. The spatial structure and tautomeric content for the synthesized ligands have been determined by means of X-ray, IR and NMR spectroscopy. Comparison of the sensitizing properties of tetrathiacalix[4]arenes and their calix[4]arene analogues on the Tb³⁺-centered luminescence in DMF solutions has been performed. A substantial enhancement of the luminescent properties of Tb³⁺- complexes with tetra-1,3-diketone ligands promoted by the tetrathiacalix[4]arene scaffold was established.     

A highly efficient ruthenium-catalyzed rearrangement of alpha,beta-epoxyketones to 1,2-diketones

TpRuPPh(3)(CH(3)CN)(2)PF(6) catalyzed the efficient rearrangement of alpha,beta-epoxyketones to 1,2-diketones. Unlike a previously reported iron catalyst, the reaction in this case is applicable not only to 1,2-disubstituted epoxides but also to mono- and trisubstituted epoxides and tolerates oxygen functionalities. The sterically crowded and highly basic tris(1-pyrazolyl)borate (Tp) ligand of the ruthenium catalyst might account for its high selectivity toward 1,2-diketone rather than 1,3-diketone.     

Observation of 1,3-diketones formation in the reaction of bulky acyl chlorides with methyllithium

The formation of 1,3-diketones was observed in the reactions of bulky acyl chlorides with methyllithium. The reaction products depend on the steric hindrance around the carbonyl group of the acyl chloride and the electronic effect of the group(s) linked to the carbonyl. When the steric hindrance around the carbonyl group of the acyl chloride is big enough, the 1,3-diketone is the only product. In the case of the moderate hindrance around the carbonyl group of the acyl chloride, a moderate yield of 1,3-diketone is obtained and some tertiary alcohol is generated. When there is no steric hindrance around the carbonyl group of the acyl chloride, the tertiary alcohol is the only product. When the steric hindrance around the carbonyl group is moderate and an electron-donating group is connected to the carbonyl of the acyl chloride, all three products--ketone, 1,3-diketone and tertiary alcohol--can be isolated from the reaction mixture after long reaction times.     

Microwave assisted rapid,catalyst-free,and efficient synthesis of a new class of diversely functionalized 3-hydroxy-2-oxindole scaffolds under aqueous reaction media

An efficient and rapid synthesis of a new class of diversely functionalized 3-substituted, 3-hydroxy-2-oxindoles scaffolds in catalyst-free conditions is described by the reaction of 1,3-diketone with isatins under microwave irradiation in aqueous medium. The generality of the reaction to afford the γ regioselective aldol addition products is well demonstrated by screening different structurally varied 1,3-diketone nucleophiles as well as isatin electrophiles. Simple reaction condition, good isolated yield of the product, and environmentally benign medium are attractive features of the present protocol.     

1,3-Diketone Calix[4]arene Derivatives—A New Type of Versatile Ligands for Metal Complexes and Nanoparticles

The present review is aimed at highlighting outlooks for cyclophanic 1,3-diketones as a new type of versatile ligands and building blocks of the nanomaterial for sensing and bioimaging. Thus, the main synthetic routes for achieving the structural diversity of cyclophanic 1,3-diketones are discussed. The structural diversity is demonstrated by variation of both cyclophanic backbones (calix[4]arene, calix[4]resorcinarene and thiacalix[4]arene) and embedding of different substituents onto lower or upper macrocyclic rims. The structural features of the cyclophanic 1,3-diketones are correlated with their ability to form lanthanide complexes exhibiting both lanthanide-centered luminescence and magnetic relaxivity parameters convenient for contrast effect in magnetic resonance imaging (MRI). The revealed structure–property relationships and the applicability of facile one-pot transformation of the complexes to hydrophilic nanoparticles demonstrates the advantages of 1,3-diketone calix[4]arene ligands and their complexes in developing of nanomaterials for sensing and bioimaging.     

Hetero diacylation of 1,1-diborylalkanes: Practical synthesis of 1,3-diketones

An efficient protocol for the synthesis of asymmetric 1,3-diketones was reported through diacylation of 1,1-diborylalkanes using two different acyl sources. In this transformation, an enolate boron species was initially formed by introducing an acyl group, then it was trapped by another acyl group to form 1,3-diketone. This method not only provided the gateway to obtain a series of 1,3-diketones, but also afforded an operationally simple and efficient access to pyrazoles and isoxazoles.     

An efficient and green synthesis of phthalide-fused pyrazole and pyrimidine derivatives

An efficient and green method for the synthesis of phthalide [isobenzofuran-1(3H)-one] fused pyrazoles via the catalyst-free condensation reaction of 2-formylbenzoic acid, hydrazine hydrate, and acetylenic esters in water is reported. Reaction of 2-formylbenzoic acid with 6-amino-uracils or cyclic 1,3-diketones resulted in the formation of phthalide-fused pyrimidine or cyclic 1,3-diketone derivatives.     

An efficient route for commercially viable syntheses of furan- and thiophene-anellated β-hydroxychalcones

An efficient route for the syntheses of β-hydroxychalcones containing benzofuran and benzothiophene rings is described. Isoxazolines obtained from oxime-olefin cycloadditions were reduced under pressure to a mixture of products. Isoxazoles obtained from Claisen aroylation of an ester and subsequent acid cyclization, or from isoxazolines via DDQ-mediated dehydrogenation, were subjected to catalytic hydrogenation followed by hydrolysis to afford 1-phenyl-3-(benzofuran-5-yl)-1,3-diketone and 1-phenyl-3-(benzothiophene-5-yl)-1,3-diketones in very good yields.     

β-双酮三苯基膦混配铜（I）配合物的合成、晶体结构及荧光性质

按文献方法合成了9-丁基-3-(4,4,4-三氟-1,3-丁二酮基)咔唑(L),以L和三苯基膦为配体与硝酸铜、铜粉反应制备了具有荧光活性的铜(Ⅰ)配合物。利用红外光谱和元素分析表征了配合物的组成。通过单晶X射线衍射分析确定了该配合物的晶体结构,晶体属于单斜晶系,P21/c空间群。晶胞参数:a=1.642 8(5)nm,b=1.043 4(5)nm,c=2.800 1(5)nm,V=4.800(3)nm3,Z=4,Dc=1.313 Mg/m3,R[I>2σ(I)],R1=0.050 1,wR2=0.080 8。该配合物的分子中,β-二酮配体L的2个O原子和三苯基膦配体的P原子参与配位,Cu(Ⅰ)处于畸变四面体配位中心。初步研究了Cu(Ⅰ)配合物的发光性质,配合物在二氯甲烷溶液中有很强的荧光发射。     

1,3-Dicarbonyl compounds as phosphine-free ligands for Pd-catalyzed Heck and Suzuki reactions

Some 1,3-dicarbonyl compounds (such as pentane-2,4-dione and 3-oxo-N-phenylbutanamide) were found to constitute highly efficient, yet low-priced and phosphine-free ligands for the Pd-catalyzed Heck and Suzuki reactions of aryl bromides and iodides with very high turnover numbers (ca. 103-104).     

Ceric ammonium nitrate supported HY-zeolite：An efficient catalyst for the synthesis of 1, 8-dioxo-octahydroxanthenes

Ceric ammonium nitrate （CAN） supported HY-zeolite has been used as an efficient catalyst for the one- pot synthesis of 1,8-dioxo-octahydroxanthenes from the readily available 1,3-diketone and aromatic aldehydes under solvent-free conditions. The present methodology is cost-effective in addition to other advantages like high yields of products in shorter reaction time and simple workup procedure without the use of any injurious solvents.     

Alkylation of sterically hindered 1,3-diketones under phase-transfer conditions

Sterically hindered 1,3-diketones react selectively with propargyl and allyl bromides under conditions of phase transfer catalysis to giveC-alkylated products, whereas reactions with butyl and benzyl chlorides yield mixtures ofC- andO-isomers. An increase in the size of the substituents present in the initial 1,3-diketone hampers introduction of the second propargyl group. The propargyl-substituted 1,3-diketones undergo cyclization under the alkylation conditions to give substituted furans.     

Synthesis of 1,3-diketo derivatives of calix[4]arene with nonyl substituents at the lower rim as novel efficient sensibilizers of Tb<Superscript>3+</Superscript> luminescence

Novel bis- and tetra-1,3-diketo derivatives of calix[4]arene with nonyl substituents at the lower rim have been synthesized. Their conformational and tautomeric composition have been determined; spectral parameters and complex formation properties with Tb³⁺ have been studied. Substitution of two 1,3-diketo groups with bromine under going from tetra- to bis 1,3-diketone derivatives was resulted in twofold increase luminescence intensity in their terbium complexes. Lifetime of the excited state of the terbium luminescence of the corresponding complexes as well as lifetime of excited triplet level of the 1,3-diketonate ligands have been determined.     

Development of formaldehyde sensing element using porous glass impregnated with beta-diketone

We have developed a sensor element for detecting formaldehyde. The sensor element is made of porous glass impregnated with both β-diketone and ammonium ions. We used three kinds of β-diketone; acetylacetone, 1-phenyl-1,3-butanedione, and 1,3-diphenyl-1,3-propanedione. The three kinds of sensor element, which are initially colorless, turn yellow after exposure to formaldehyde, and absorption with a peak wavelength of 407–424 nm appears. There is a linear relationship between the 407–424 nm absorbance of the sensor element after exposure to formaldehyde, and the formaldehyde concentration. The sensor element also works cumulatively, and the absorbance changes of the three kinds of sensor elements are acetylacetone > 1-phenyl-1,3-butanedione > 1,3-diphenyl-1,3-propanedione, when exposed to the same concentration of formaldehyde in the atmosphere. We also found that both the formation and decomposition reactions of lutidine derivative (yellow dye) occur on the acetylacetone element at 20 °C, and the kinetic constant of the former is 100,000 times larger than that of the latter. On the other hand, only the formation reaction occurs on the 1-phenyl-1,3-butanedione element at 20 °C. Therefore, the acetylacetone element would be suitable for short-term measurements and the 1-phenyl-1,3-butanedione would be suitable for long-term measurements.     

A 2,6‐Bis(phenylamino)pyridinato Titanium Catalyst for the Highly Regioselective Hydroaminoalkylation of Styrenes and 1,3‐Butadienes

The C? C bond forming catalytic hydroaminoalkylation of terminal alkenes, 1,3‐dienes, or styrenes allows a direct and highly atom efficient (100 %) synthesis of amines which can result in the formation of two regioisomers, the linear and the branched product. We present a new titanium catalyst with 2,6‐bis(phenylamino)pyridinato ligands for intermolecular hydroaminoalkylation reactions of styrenes and 1‐phenyl‐1,3‐butadienes that delivers the corresponding linear hydroaminoalkylation products with excellent regioselectivities.     

One-pot, multicomponent route to pyrazoloquinolizinones

[reaction: see text] An efficient synthesis of 5a-hydroxy-4,5,5a,6,7,8-hexahydropyrazolo[4,3-c]quinolizin-9-ones based on the three-component condensation of 5-aminopyrazoles, aromatic aldehydes, and cyclic 1,3-diketones is described. The multicomponent reaction is performed under strongly basic conditions applying controlled microwave heating in a sealed vessel and involves an unusual base-mediated ring-opening/recyclization of the cyclic 1,3-diketone moiety.     

丙二硫醚桥联双β-二酮分子的合成及其离子识别与萃取性能

由Williamson反应合成了1,3-丙二硫醚基桥联2个乙酰丙酮的双-β-二酮化合物1,3-二(3-硫醚基-2,4-戊二酮基)丙烷（L1）,其分子结构经元素分析、1H NMR、13C NMR、MS、IR及UV等技术手段表征,采用单晶X射线衍射方法确定了双β-二酮L1的晶体结构,双β-二酮L1属于单斜晶系,C2/c空间群,晶胞参数a=1.40679(9) nm,b=0.76521(5) nm,c=1.43213(10) nm,α=γ=90°,β=94.552°,V=1.53681(18) nm3,Z=4,Dc=1.316 g/cm3,μ=0.353 mm-1,F(000)=648;结构分析表明,双β-二酮L1在固体或氯仿溶液中均是以烯醇式异构体形式存在。 通过紫外光谱法考察了双β-二酮L1对金属离子的识别能力和萃取性能,结果表明,双β-二酮L1对Ni(Ⅱ)离子具有良好的选择性识别作用和萃取选择性能。