Mechanochemical synthesis of oxygenated alkynyl carbon materials with excellent Hg(Ⅱ) adsorption performance from CaC2 and carbonates

Adsorptive removal of heavy metal ions from wastewater is very important,and the key is the development of efficient sorbents.In this work,oxygenated alkynyl carbon materials(OACMs)were synthesized via mechanochemical reaction of CaC_(2) and a carbonate(CaCO_(3),Na2CO_(3),or NaHCO_(3))at ambient temperature.The resultant OACMs are micro mesoporous carbon nanomaterials with high specific area(>648 m2 g^(-1)),highly crosslinked texture,and rich alkynyl and oxygenated groups.The OACMs exhibit excellent Hg(Ⅱ)adsorption due to the soft acid-soft base interaction between alkynyl and Hg(Ⅱ),and OACM-3 derived from CaC_(2) and NaHCO_(3) has the saturated Hg(Ⅱ)adsorbance of 483.9 mg g^(-1)along with good selectivity and recyclability.The adsorption is mainly chemisorption following the Langmuir mode.OACM-3 also shows high adsorbance for other heavy metal ions,e.g.256.6 mg g^(-1)for Pb(II),232.4 mg g^(-1)for Zn(II),and 198.7 mg g^(-1)for Cu(II).This work expands the mechnochemical reaction of CaC_(2)with carbonates and possibly other oxyanionic salts,provides a new synthesis approach for functional alkynyl carbon materials with excellent adsorption performance for heavy metal ions,as well as a feasible approach for CO2 resource utilization.

The alkynyl-containing compounds from mushrooms and their biological activities

Mushrooms have been utilized by humans for thousands of years due to their medicinal and nutritional properties.They are a crucial natural source of bioactive secondary metabolites,and recent advancements have led to the isolation of several alkynyl-containing compounds with potential medicinal uses.Despite their relatively low abundance,naturally occurring alkynyl compounds have attracted considerable attention due to their high reactivity.Bioactivity studies have shown that alkynyl compounds exhibit significant biological and pharmacological activities,including antitumor,antibacterial,antifungal,insecticidal,phototoxic,HIV-inhibitory,and immunosuppressive properties.This review systematically compiles 213 alkynyl-containing bioactive compounds isolated from mushrooms since 1947 and summarizes their diverse biological activities,focusing mainly on cytotoxicity and anticancer effects.This review serves as a detailed and comprehensive reference for the chemical structures and bioactivity of alkynyl-containing secondary metabolites from mushrooms.Moreover,it provides theoretical support for the development of chemical constituents containing alkynyl compounds in mushrooms based on academic research and theory.

A new synthesis of alkynyl tellurides promoted by CsOH and 4 MS

The mixture of cesium hydroxide and terminal alkynes in dry DMF in the presence of 4 A molecular sieves was stirred for 3.0 h at room temperature under N2, then aryltellurenyl bromide in THF was added, and the reaction mixture was stirred for 2.0 h. Alkynyl tellurides were obtained in about 90% yields by flash chromatography.

Triphenylphosphine-catalyzed isomerization of alkynyl ketones in aqueous solution

An efficient isomerization of alkynyl ketones to (E,E)-diene ketones was developed. The reaction catalyzed by 20 mol% triphenylphosphine in aqueous media gave the desired products in good yields.

High extraction ability of 1,3-dialkynyl calixarene towards mercury(Ⅱ) ion

The reaction of 1,3-dipropyn-2-yloxycalix[4]arene with mercury（U） acetate could give mercury-containing alkynyl calixarene polymer. The extraction behavior of 1,3-dipropyn-2-yl-oxycalix[4]arene towards mercury（Ⅱ） ion was examined. When the mole ratio of Hg^2＋/calixarene was 1：1, the extractive percent can reach to 99.1%, and the extraction capacity was up to 431 mg/g. It could also decrease the Hg^2＋ concentration from 5 to 0.85 mg/L, which was only 17% of the national standard of effluent and satisfied the national standard of drinking water. The extraction process included chemical reaction.

The applications of Schiff bases in Ti-catalyzed asymmetric alkynylation of aldehydes

Sciff bases 1 and 2, .which were derived from chiral aminoalcohols, were used as figands in Ti-catalyzed asymmetric alkynylation of aldehydes. Good enantioselectivities （up to 88% ee） and high chemical yields （80-90%） were obtained.

Synthesis,Structure and Photophysical Properties of Heteronuclear Pt_2Cu Alkynyl Complexes

Two luminescent hetero-trinuclear complexes [Pt2Cu（μ-dpppy）2（C≡CC6H4R-4）4]（Cl O4）（R = H,1;R = CH3,2;dpppy = 2,6-bis（diphenylphosphino）pyridine） have been synthesized and characterized by elemental analyses,ESI-MS,^1H and ^31P{^1H} NMR spectroscopy,and X-ray crystallography for 2.Their photophysical properties in the solid state and in solutions at room temperature and in frozen glasses at 77 K were studied.Both complexes 1 and 2 show strong orange-red emission in the solid state at room temperature and in frozen glasses at 77 K,and weak emission in solutions.

Stereoslective Synthesis of (Z)-1, 2-Bis(arylseleno)-1-alkene by Addition of Cesium Arylselenolate to Alkynyl Selenide

Alkynyl selenide reacted with cesium arylselenolate in commercial THF at r.t under N2 to afford (Z)-1, 2-bis(arylseleno)-1-alkene in high yields.

Cobalt-catalyzed reductive alkynylation to construct C(sp)-C(sp^(3))and C(sp)-C(sp^(2))bonds

Transition-metal-catalyzed cross-electrophile coupling has emerged as a reliable method for constructing carbon–carbon bonds.Herein,we report a general method,cobalt-catalyzed reductive alkynylation,to construct C(sp)-C(sp^(3))and C(sp)-C(sp^(2))bonds.This presented reaction has a broad substrate scope,enabling the efficient cross-electrophile coupling between alkynyl bromides with alkyl halides and aryl or alkenyl(pseudo)halides.This presented reaction is conducted under mild conditions,tolerating many functional groups,thus suitable for the modification and synthesis of biologically active molecules.

Transition-metal-catalyzed remote meta-C-H alkylation and alkynylation of aryl sulfonic acids enabled by an indolyl template

Transition-metal-catalyzed remote sp^(2)C-H functionalization of aryl sulfonic acids was hardly ever real-ized owing to competitive ortho-C-H functionalization of aryl sulfonates and electron-deficient nature of phenyl ring.Herein,with the assistance of a practical biaryl indolyl directing template,palladium-catalyzed remote sp^(2)C-H alkylation of aryl sulfonic acids have been achieved in moderate to good yields with exclusive meta selectivity.Moreover,remote meta-selective C-H alkynylation of aryl sulfonic acids was also accomplished with a rhodium catalyst.These meta-C-H functionalized products proved to be the superior synthetic precursors,which are difficult to access using the conventional strategy.

Ru(Ⅱ)-Catalyzed Selective C-H Alkynylation of Isoquinolones,Quinazolones and Phthalazinones with Bromoalkynes

A new,selective Ru(Ⅱ)-catalyzed alkynylation reaction of isoquinolones,quinazolones and phthalazinones with readily available bromoalkynes has been developed.This reaction enables the selective construction of a new C(sp^(2))-C(sp)bond through C-H activation and C-Br functionalization,and offers an effective and selective route to synthesizing highly valuable alkynylated isoquinolone,quinazolone and phthalazinonederivatives with a wide substrate scope and highselectivity.

Pd-catalyzed asymmetric carbonyl alkynylation:Synthesis of axial chiral ynones

Ynones are important skeletons in bioactive molecules and valuable building blocks for organic synthesis,thus great efforts have been devoted to their preparation.While,introducing prochiral substrates to construct ynones bearing a chiral framework is unrealized to date.Herein,we reported the first example of Pd/SOP-catalyzed asymmetric carbonylative alkynylation via a non-classical carbonylative Sonogashiratype approach(acyl-Pd(Ⅱ)species generated from nucleophiles).By using cyclic diaryliodonium salts as prochiral substrates,various axial chiral ynones with good functional group tolerance(39 examples),satisfied yields(71%-96%)and excellent enantioselectivities(generally 94%-99%ee)were produced.Synthesis of bioactive compounds,scale-up experiment and useful transformations were also conducted to demonstrate the utility of this process.

Visible-light-induced decarboxylative alkynylation of carboxylic acids in batch and continuous flow

A green efficient photoredox-catalyzed decarboxylative alkynylation of carboxylic acids with alkynyl bromides has been developed.This broadly applicable protocol is presented whereinα-amino,aliphatic andα-oxy acids are converted into useful alkynylation products.The commercially-available organic photocatalyst 4CzIPN is used as the photocatalyst,organic base DBU is utilized as the base,and DMSO serves as solvent.This strategy features mild conditions,is metal-free,and is environmentally friendly.The batch and continuous-flow protocols described were applied to obtain a broader substrate scope of functionalization(more than 50 examples).Furthermore,we demonstrate that the use of microflow technology enhanced and intensified the reaction process,achieving significantly reduced reaction times(i.e.,10 min of residence time).

Recent Developments in Copper(Ⅰ)-Catalyzed Enantioselective Alkynylation Reactions via a Radical Process

Alkynes are one of the most significant functional groups in organic chemistry and great efforts have been made to explore efficient approach for the construction of chiral alkynes.The asymmetric C(sp^(3))–C(sp)cross-coupling provides a significant complementary strategy through radical-initiated process.However,the stereocontrol of highly reactive and unstable radical intermediate has been a challenge for decades.To address this problem,a variety of chiral ligands are developed for initiating the reaction and achieving enantiocontrol of alkyl radicals.This review summarizes recent developments in copper-catalyzed enantioselective alkynylation of prochiral alkyl radicals and their brief mechanistic studies.

Heterointerface of all-alkynyl-protected Au_(28) nanoclusters anchored on NiFe-LDHs boosts oxygen evolution reaction:a case to unravel ligand effect

Ultrasmall Au nanoclusters have been proven to effectively enhance the catalytic performance of NiFe layered double hydroxides(NiFe-LDHs)toward oxygen evolution reaction(OER),yet the surface ligand effect of the Au nanoclusters still remains elusive.Herein,a systematic study is reported to examine the OER performance of NiFe-LDHs supported atom-precise all alkynyl-protected[Au_(28)(~tBuC≡C)17]~-nanoclusters(Au_(28)-Alkynyl in short)and thiolate-protected Au_(28)(TBBT)_(20)(TBBT=4-tert-butylbenzene thiol)counterp arts(Au_(28)-Thiolate in short).The Au_(28)-Alkynyl cluster has characteristic absorbance feature,and its composition is verified by mass spectrometry.It possesses a drastically different structure from the reported mixed ligand protected Au_(28)nanoclusters.Interestingly,the NiFe-LDHs loaded with Au_(28)-Alkynyl exhibited a superior OER performance than the sample loaded with Au28-Thiolate under the same conditions,evidenced by a smaller overpotential of 205 mV at the current density of 10 mA·cm^(-2)and a lower Tafel slope value of 41.0 mV·dec^(-1)in 1 mol·L^(-1)KOH.Such excellent performance is attributed to the interfaces created between the NiFe-LDHs and the Au nanoclusters,as density functional theory calculations reveal that more significant charge transfer occurs in Au_(28)-Alkynyl/NiFeLDHs catalyst,and more importantly,the energy barrier of the potential-determining step in the OER process for Au28-Alkynyl/NiFe-LDHs is much lower than that of Au28-Thiolate/NiFe-LDHs hence favors the electrocatalytic reaction.

Atomically precise alkynyl-protected Ag_(20)Cu_(12)nanocluster:Structure analysis and electrocatalytic performance toward nitrate reduction for NH_(3)synthesis

Electrochemical nitrate reduction reaction(NtrRR)has been emerging as an appealing route for both water treatment and NH_(3)synthesis.Herein,we report the structure analysis and electrocatalytic performance of a novel homoleptic alkynyl-protected Ag_(20)Cu_(12)nanocluster(Ag_(20)Cu_(12)in short)with atomic precision,which has eight free electrons and displays characteristic absorbance feature.Single crystal X-ray diffraction(SC-XRD)discloses that,it adopts a Ag_(14)kernel capped by three Ag_(2)Cu_(4)(C≡CArF)_(8)metal–ligand binding motifs in the outer shell.Ag_(20)Cu_(12)exhibited excellent catalytic performance toward NtrRR,as manifested by the superior NH_(3)Faradaic efficiency(FE,84.6%)and yield rate(0.138 mmol·h^(−1)·mg−1)than the homoleptic alkynyl-protected Ag_(32)nanoclusters.Additionally,it demonstrates good catalytic recycling capability.Density functional theory(DFT)calculations revealed that,the de-ligated Ag_(20)Cu_(12)cluster can expose the available AgCu bimetallic sites as the efficient active sites for NH_(3)formation.In particular,the participation of Cu sites greatly facilitates the initial capture of NO_(3)−and simultaneously promotes the selectivity of the final product.This study discovers a novel homoleptic alkynyl-protected AgCu superatom,and offers a great example to elucidate the structure–performance relationship of bimetallic catalyst for NtrRR and other multiple protons/electrons coupled electrocatalytic reactions.

Palladium-Catalyzed Oxidative Alkynylation of Allenyl Ketones: Access to 3-Alkynyl Poly-substituted Furans

Furans bearing alkynyl substituents are highly useful in organic synthesis.However,the methodologies to access these important furan derivatives are rather limited.We herein report an efficient synthesis of alkynylated furan derivatives based on Pd-catalyzed oxidative cross-coupling reaction between allenyl ketones and terminal alkynes.This novel synthesis of alkynylated furans with wide substrate scope is operationally simple and tolerates various functional groups.Mechanistically,the formation of the palladium carbene through cycloisomerization and the subsequent alkynyl migratory insertion are proposed as the key steps in the transformation.The reaction reported in this paper further demonstrates the generality of the carbene-based cross coupling.

Synthesis of alkynes and alkynyl iodides bearing a protected amino alcohol moiety as functionalized amino acids precursors

Amino acid precursors in protected amino alcohol form are important synthons that can be used as building-blocks for the hemisynthesis of non-natural amino acids.Serine can be used as a common starting material for the synthesis of such compounds differently protected.Particularly,protected amino alcohols bearing an ethynyl and/or an iodoethynyl group can be used in cross-couplings,in 1,3-dipolar cycloadditions and/or in Nozaki-Hiyama-Kishi type reactions.We thus demonstrated that the efficiently protected amino alcohols derived from serine can be coupled to a sugar derivative by an indium mediated alkynylation reaction.The conditions of this coupling are compatible with such functionalized derivatives and allow envisaging an access to C-glycosylated amino acids.

氧化石墨烯对靶向吸氢纳米复合材料吸氢性能影响研究

以氧化石墨烯(GO)作为载体的有机吸氢材料和其催化剂的复合材料,在低温真空领域具备较优的应用前景。为研究载体材料GO对复合材料的形貌和吸氢性能的影响,制备了氧化石墨烯基纳米复合材料(Alkyne-PVA-(GO-PdO)),通过XRD、^(1)H-NMR、SEM和TEM对其进行了表征,并与无氧化石墨烯的纳米复合材料(PdO@Alkyne-PVA)进行对比。结果表明,PdO和炔基化聚乙烯醇(Aklyne-PVA)能够成功负载在GO上,Alkyne-PVA-(GO-PdO)上的PdO纳米粒子分布良好,平均粒径为2.1 nm。采用静态膨胀法对两种吸氢材料的吸氢性能进行研究对比发现,Alkyne-PVA-(GO-PdO)在平衡压力为463.8 Pa时,吸氢量达到了11048.25 Pa·L/g,而PdO@Alkyne-PVA在平衡压力为560.21 Pa下,吸氢量仅达到4528.35 Pa·L/g。这归因于GO较高的比表面积和表面大量的含氧官能团、缺陷和空位改善了PdO纳米粒子的团聚问题。此外,GO在吸氢反应过程中保证了PdO纳米粒子不会因发生团聚现象而阻碍后续吸氢反应,使得产物钯金属发挥了其最优的催化性能,同时GO的氢溢流效应加速了解离后的氢原子的扩散,有效增强了复合材料的吸氢性能。文章验证了GO在吸氢领域中良好的应用潜力,为以GO为基底的吸氢材料的实现提供了可能。

Alkynyl carbon materials as novel and efficient sorbents for the adsorption of mercury(Ⅱ) from wastewater

For the first time, a series of alkynyl carbon materials（ACMs） were prepared via the mechanochemical reaction of CaC2 with six polyhalogenated precursors, namely CCl4,C2Cl6, C2Cl4, C6Cl6, C6Br6, and C14H4Br10（ACM-1, ACM-2, ACM-3, ACM-4, ACM-5, and ACM-6,respectively） and used for the adsorptive removal of mercury from aqueous solutions.Based on preliminary investigations, the adsorption of mercury on ACM-5 was studied in depth. Specifically, the effect of p H on mercury adsorptivity, adsorption kinetics,thermodynamics, isotherms, and recyclability was studied. The adsorptivity of mercury on ACMs was found to be closely related to the hydrocarbon precursor, specific surface area of sorbent, and the alkynyl content. ACM-5 showed the best performance and is among the best raw carbonaceous sorbents reported so far, with a Langmuir saturated adsorption capacity of 191.9 mg g-1. The promising mercury adsorption performance mainly arises from the strong Lewis soft acid–soft base interactions between the alkynyl groups and mercury ions. The adsorption isotherms could be satisfactorily correlated with the Langmuir equation. The results show that the ACMs can be used as efficient sorbents for the removal of mercury and may also be useful for the adsorption of other heavy metals.