- A base-promoted tandem approach to bicyclic 8-membered ring ketones
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A base-promoted tandem route toward unprecedented bicyclic 8-membered ring ketones is reported. Under our approach, the targeted products are delivered in high yields from phenylacetylenes and 1,3-diketones. The method has a good scope and gives access to a complex structure that offers a wealth of opportunities for further functionalization.
- dos Santos, Emerson E. F.,de Souza, Gabriela F. P.,Simoni, Deborah A.,Salles, Airton G.
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- Tandem Aminocarbonylation/ Pauson-Khand Reaction of Haloacetylenes
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(Matrix Presented) The dicobalt hexacarbonyl complex of 1-chloro-2-phenylacetylene decomposes in solution at room temperature affording similar amounts of two new complexes, to which the structures of a dichloro tetracobalt decacarbonyl complex of 1,4-diphenyl-1,3-butadiyne and of a 1-chloro-2-phenylacetylene acylcobalt complex have been tentatively assigned. The acyl complex can be efficiently trapped by amines, and the resulting aminocarbonylation products submitted to Pauson-Khand reaction to yield cyclopentenones with the regiocontrolled formation of five new bonds in a single synthetic operation.
- Balsells, Jaume,Moyano, Albert,Riera, Antoni,Pericas, Miquel A.
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- Enantioselective Decarboxylative α-Alkynylation of β-Ketocarbonyls via a Catalytic α-Imino Radical Intermediate
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A distinctive aminocatalysis via α-imino radical is reported on the basis of SET oxidation of a secondary enamine. The combination of chiral primary amine catalysis and visible-light photoredox catalysis enables the enantioselective decarboxylative coupling of propiolic acid and β-ketocarbonyls to afford alkynylation adducts with high enantioselectivity. Mechanism studies indicate the reaction proceeds via an α-imino radical addition.
- Wang, Dehong,Zhang, Long,Luo, Sanzhong
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- Development and Optimization of Glaser-Hay Bioconjugations
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The prevalence of bioconjugates in the biomedical sciences necessitates the development of novel mechanisms to facilitate their preparation. Towards this end, the translation of the Glaser-Hay coupling to an aqueous environment is examined, and its potent
- Lampkowski, Jessica S.,Villa, Jordan K.,Young, Travis S.,Young, Douglas D.
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- Selective Carboxylate Directed ortho Functionalization in Copper Catalyzed Reactions of Polyiodo Aromatics: A Straightforward Preparation of 5,7-Diiodo-1H-isochromen-1-ones
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A facile, and totally regioselective one-pot approach to synthesize 5,7-diiodo-3-substituted-isocoumarins is described. This reaction was realized by using copper iodide as the catalyst under mild reaction conditions. The methodology was used to design a wide variety of compounds and was tolerant to a large number of functional groups. Interestingly, among the three possible carbon–iodine bonds, only one was reactive, which left the two others intact for further functionalization.
- Anselmi, Elsa,Bahlaouan, Zineb,Inack Ngi, Samuel,Parrain, Jean Luc,Magnier, Emmanuel,Abarbri, Mohamed
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- Diyne coordination chemistry: Reactions of with diphenylbutadiyne and bis(phenylethynyl)mercury
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The reaction of the hydridometal complex with 1,4-diphenyl-butadi-1,3-yne has been investigated and found to proceed with monoinsertion to give a coordinatively unsaturated ?-vinyl complex CPh)=CHPh>Cl(CO)(PPh3)2>, which is a
- Hill, Anthony F.,Melling, Richard P.
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- Selective synthesis of 2-aryl-3-alkenylindoles and 2-aryl-3-alkynylindoles by palladium-catalyzed ligand-promoted annulative coupling of anilines and propargyl alcohols
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A palladium-catalyzed annulative reaction between aniline and propargyl alcohol has been developed. Propargyl alcohols act as internal or terminal alkynes in the reactions through C?H/C?C activation in the presence of Ac-Gly-OH or Xantphos as ligand, resulting in the formation of 3-alkenylindoles or 3-alkynylindoles respectively. The incorporated alkenyl and alkynyl groups could be engaged for further derivations to form versatile indole skeletons with potential applications.
- Li, Qiang,Xia, Ying,Yan, Xufei,Zhou, Xiangge,Zhu, Maoshuai
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- Copper-catalyzed synthesis of thiazolidine derivatives via multicomponent reaction of terminal alkynes, elemental sulfur, and aziridines
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Abstract: An atom-economic catalytic multicomponent reaction between terminal alkynes, elemental sulfur, and aziridines has been reported. In this transformation, alkyne thiolate derived from the reaction of terminal alkynes and elemental sulfur in the presence of CuOTf/DBU reacted with aziridines to afford thiazolidine derivatives. Graphical abstract: [Figure not available: see fulltext.].
- Khalaj, Mehdi,Sadeghpour, Mahdieh,Mousavi Safavi, Seyed Mahmoud,Lalegani, Arash,Khatami, Seyed Mola
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- Unusual Transformations of Highly Unsaturated Trifluoromethanesulfonamide Derivatives
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Oxidative condensation of N,N-bis(prop-2-yn-1-yl)trifluoromethanesulfonamide in DMSO involved only one ethynyl group, whereas in aqueous methanol 1,8-bis(trifluoromethanesulfonyl)-1,8-diazacyclotetradeca-3,5,10,12-tetrayne was obtained. N,N′-(Hexa-2,4-diyn-1,6-diyl)bis(trifluoromethanesulfonamide) in hexane solution was unexpectedly converted to diphenyldiacetylene, presumably, as a result of annulation of highly unsaturated carbon chains in the initial polyacetylene molecule and elimination of trifluoromethanesulfonamide and trifluoromethanesulfonamidomethyl residues.
- Ushakova,Shainyan
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- Copper-catalyzed diversity-oriented three- and five- component synthesis of mono- and dipropargylic amines via coupling of alkynes, α-Amino esters and aldehydes
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Mono- as well as dipropargylic amines were synthesized using α-amino esters as inexpensive building blocks under a single catalytic system (copper bromide, 100 °C, 4 h, toluene) where the reactant ratio (1a/2a/3a) acted as product specific switch. Both secondary (mono) as well as tertiary (di) propargylic amines formed via three- and five-component coupling exhibited wide substrate scope with moderate to good yields and satisfactory diastereoselectivity in a few cases. The practical utility of the method is enhanced by providing a facile access to enantiopure propargylic amines via lipase-catalyzed resolution along with synthesis of unsymmetrical dipropargylic amines, secondary propargylic amines bearing quaternary carbon centers and imidazolidin-2-ones.
- Sharma, Nandini,Sharma, Upendra K.,Mishra, Nigam M.,Van Der Eycken, Erik V.
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- Synthesis and spectroscopic characterization of ?-bonded phenothiazinonepalladium complexes
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Treatment of 4-iodo-3H-phenothiazin-3-one with tetrakis(triphenylphosphine)palladium(0) in boiling benzene yields trans-iodo(3H-phenothiazin-3-one-4-yl)bis(triphenylphosphine)palladium(II) by oxidative addition. 5H-Benzo>phenothiazin-5-one-6-yl complex is prepared in a similar manner.The ?-bonded iminoquinone structure of the complexes has been elucidated by 1H, 13C, and 31P NMR spectroscopy.
- Konishi, Hisatoshi,Matsumura, Chisato,Okano, Tamon,Kiji, Jitsuo
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- The first Heck reactions with 1-chloroalk-1-ynes: Syntheses of enynes with isolated and conjugated π-systems
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The Heck reaction between 1-chloro-2-phenylacetylene and cycloalkenes or cycloalkadienes affords phenylethynyl substituted cycloalkenes as regular Heck products as well as 1,3-diphenylprop-2-ynylidene and (cycloalkenyl)phenylmethylidene substituted bicyclic compounds as tandem products by reaction of ClC≡CPh and the cycloalkene in a ratio of 1:2 and 2:1, respectively.
- Weigelt, Michael,Becher, Diana,Stroehl, Dieter,Bruhn, Clemens,Poetsch, Eike,Steinborn, Dirk
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- Cu(OAc)2-catalysed oxidative dual C-H/N-H activation of terminal alkynes and N-deprotected sulfonimidamides: An easy access to N-alkynylated sulfonimidamides
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We report a mild and efficient Cu(OAc)2-catalysed protocol for the oxidative C-N cross-coupling of terminal alkynes and N-deprotected sulfonimidamides. The reaction leads to hitherto unknown N-alkynylated sulfonimidamides. Furthermore, we found that the synthesised N-alkynylated sulfonimidamides could undergo silica-gel-mediated hydrolysis to give the corresponding N-acyl-sulfonimidamides, as well as borane-dimethyl sulfide-mediated reduction to give the corresponding N-alkylated sulfonimidamides.
- Nandi, Ganesh Chandra,Kota, Sudhakar Rao,Naicker, Tricia,Govender, Thavendran,Kruger, Hendrick G.,Arvidsson, Per I.
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- Rhodium-Catalyzed/Copper-Mediated Selective C2 Alkynylation of Indoles and C1 Alkynylation of Carbazoles with γ-Substituted tert-Propargyl Alcohols
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A novel rhodium-catalyzed/copper-mediated C2-selective C?H alkynylation of indoles using γ-substituted tert-propargyl alcohols as the alkynylating reagent and a removable 6-methylpyridin-2-yl as the directing group has been developed, which provides a viable pathway for direct C2-selective alkynylation of indoles. Moreover, this strategy could be extended to the C?H alkynylation of carbazoles at the C1 position.
- Li, Ting,Wang, Zhen,Qin, Wen-Bing,Wen, Ting-Bin
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- Aerobic Copper Catalysis for Tandem Oxy-N-alkenylation of [1,2,3]Triazolo[1,5-a]pyridines
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N-Alkenylated triazolinone ylides were generated through copper-catalyzed oxy-N-alkenylation of triazolopyridines. The mechanistic course of this aerobic tandem reaction has been experimentally elucidated and primary photophysical data of the ylide products are also given. (Figure presented.).
- Pankajakshan, Sreekumar,Ang, Wei Li,Sreejith, Sivarampanicker,Stuparu, Mihaiela Corina,Loh, Teck-Peng
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- Rhodium-catalyzed annulative coupling of: N-aryl-2-aminopyridine and propargylic amine via selective C-C and C-H bond activation
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A Rh(iii)-catalyzed/Cu(ii)-mediated cascade reaction between N-aryl-2-aminopyridine and propargylic amine has been developed. Selective C(sp2)-H bond activation and C(sp)-C(sp3) cleavage occurred during the reaction, which was followed by a cyclization reaction to provide an unprecedented synthetic route to form 1,2-disubstituted indoles in yields up to 85%.
- He, Shiyu,Yan, Xufei,Lei, Yanxi,Xiang, Haifeng,Zhou, Xiangge
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- Silica/chitosan core-shell hybrid-microsphere-supported CuI catalyst for terminal alkyne homocoupling reaction
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A new microfluidic approach to prepare silica/chitosan core-shell hybrid microspheres was developed. The hybrid microspheres exhibit improved mechanics and adsorption properties. In addition, the silica/chitosan-supported CuI is an outstanding catalyst fo
- Zhao, Hong,Xu, Jianhong,Wang, Tao
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- CuI-Mediated Bromoalkynylation and Hydroalkynylation Reactions of Unsymmetrical Benzynes: Complementary Modes of Addition
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Benzynes formed by heating a suitable triyne (or tetrayne) substrate are shown to react with in situ generated alkynyl copper species. The latter are compatible with the polyyne substrates and two types of chemistries have been achieved: (i) 1-bromo-1-alkynes efficiently undergo net bromoalkynylation of the (unsymmetrical) benzynes and (ii) in situ generated alkynylcopper species give rise to hydroalkynylation products. The regiochemical preferences of these two modes of reaction are complementary to one another with respect to the position of alkynyl substituent in the final products.
- Xiao, Xiao,Wang, Tao,Xu, Feng,Hoye, Thomas R.
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- Homo and hetero glaser coupling involving acetylene derivatives of trifluoromethanesulfonamide
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Glaser homocoupling of N,N-bispropargyltriflamide led to the formation of N,N′-hexa-2,4-diyne-1,6-diylbis(N-prop-2-yne-1-triflamide). Further condensation into a 14-membered heterocycle, 1,8-bis-(triflyl)-1,8-diazacyclotetradeca-3,5,10,12-tetrayne did not occur evidently because of rigid steric requirements to the cyclization. In the Glaser heterocoupling of N-propargyltriflamide with arylacetylenes ArC≡CH (Ar = Ph, p-CNC6H4) the condensation products formed in 20-30% yields.
- Shainyan,Ushakova
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- New Palladium – ZrO2 Nano-Architectures from Thermal Transformation of UiO-66-NH2 for Carbonylative Suzuki and Hydrogenation Reactions
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The new nanocomposites, Pd/C/ZrO2, PdO/ZrO2, and Pd/PdO/ZrO2, were prepared by thermal conversion of Pd@UiO-66-Zr?NH2 (MOF) in nitrogen or air atmosphere. The presence of Pd nanoparticles, uniformly distributed on the ZrO2 or C/ZrO2 matrix, was evidenced by transmission electron microscopy, scanning electron microscopy (SEM), Raman and X-ray Photoelectron Spectroscopy (XPS) methods. All pyrolysed composites retained the shape of the MOF template. They catalyze carbonylative Suzuki coupling under 1 atm CO with an efficiency significantly higher than the original Pd@UiO-66-Zr?NH2. The most active PdO/ZrO2 composite, formed benzophenone with TOF up to 1600 h?1, while by using Pd@UiO-66-Zr?NH2, much lower TOF values, 51–95 h?1, were achieved. After the reaction, PdO/ZrO2 was recovered with the same composition and catalytic activity. Very good results were also obtained in the transfer hydrogenation of benzophenones to alcohols with Pd/C/ZrO2 and PdO/ZrO2 catalysts under microwave irradiation.
- Alsalahi, Waleed,Augustyniak, Adam W.,Tylus, W?odzimierz,Trzeciak, Anna M.
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supporting information
(2021/12/22)
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- Copper-catalyzed decarboxylative Se insertion coupling of indoles and propiolic acids
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A novel and efficient copper-catalyzed decarboxylative alkynylselenation of indoles with Se powder and propiolic acids has been developed. The outstanding advantages of this protocol not only nicely avoid the use of prefabricated arylselenation reagent and address the facile over-selention issues, but also enrich the chemistry of selenium powder. Importantly, this reaction could be extended to pyrrole, and the practical utility of this transformation has been demonstrated in gram-scale synthesis and late-stage indolylselenation of Clofibrate-derived propiolic acid.
- Wang, Caihong,Wu, Ge,Zhou, Xueying
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- Synthesis of 3,4-bis(Butylselanyl)selenophenes and 4-alkoxyselenophenes promoted by oxone
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We describe herein an alternative transition-metal-free procedure to access 3,4-bis(butylsela nyl)selenophenes and the so far unprecedented 3-(butylselanyl)-4-alkoxyselenophenes. The protocol involves the 5-endo-dig electrophilic cyclization of 1,3-diynes promoted by electrophilic organosele-nium species, generated in situ through the oxidative cleavage of the Se-Se bond of dibutyl diselenide using Oxone as a green oxidant. The selective formation of the title products was achieved by controlling the solvent identity and the amount of dibutyl diselenide. By using 4.0 equiv of dibutyl diselenide and acetonitrile as solvent at 80?C, four examples of 3,4-bis(butylselanyl)selenophenes were obtained in moderate to good yields (40–78%). When 3.0 equiv of dibutyl diselenide were used, in the presence of aliphatic alcohols as solvent/nucleophiles under reflux, 10 3-(butylselanyl)-4-alkoxyselenophenes were selectively obtained in low to good yields (15–80%).
- Hellwig, Paola S.,Guedes, Jonatan S.,Barcellos, Angelita M.,Perin, Gelson,Lenard?o, Eder J.
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- One-Pot Dual C?C Coupling Reaction via Site Selective Cascade Formation by PdII-Cryptate of an Amino-Ether Heteroditopic Macrobicycle
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Selectivity of aryl iodo over ethynyl iodo toward the Suzuki cross coupling reaction is explored by utilizing a palladium complex of amino-ether heteroditopic macrobicycle. Subsequently, unreacted ethynyl iodide undergoes homocoupling reaction in the same catalytic atmosphere, thereby representing a cascade dual C?C coupling reaction. Furthermore, this approach is extended for novel one-pot synthesis of unsymmetrical 1,3-diynes.
- Sarkar, Sayan,Sarkar, Piyali,Munshi, Sandip,Ghosh, Pradyut
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p. 7307 - 7314
(2021/03/22)
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- Copper-Catalyzed Intermolecular Enantioselective Radical Oxidative C(sp3)?H/C(sp)?H Cross-Coupling with Rationally Designed Oxazoline-Derived N,N,P(O)-Ligands
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The intermolecular asymmetric radical oxidative C(sp3)?C(sp) cross-coupling of C(sp3)?H bonds with readily available terminal alkynes is a promising method to forge chiral C(sp3)?C(sp) bonds because of the high atom and step economy, but remains underexplored. Here, we report a copper-catalyzed asymmetric C(sp3)?C(sp) cross-coupling of (hetero)benzylic and (cyclic)allylic C?H bonds with terminal alkynes that occurs with high to excellent enantioselectivity. Critical to the success is the rational design of chiral oxazoline-derived N,N,P(O)-ligands that not only tolerate the strong oxidative conditions which are requisite for intermolecular hydrogen atom abstraction (HAA) processes but also induce the challenging enantiocontrol. Direct access to a range of synthetically useful chiral benzylic alkynes and 1,4-enynes, high site-selectivity among similar C(sp3)?H bonds, and facile synthesis of enantioenriched medicinally relevant compounds make this approach very attractive.
- Gu, Qiang-Shuai,Guo, Kai-Xin,Li, Zhong-Liang,Liu, Lin,Liu, Xin-Yuan,Tian, Yu,Yang, Chang-Jiang,Ye, Liu
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supporting information
p. 26710 - 26717
(2021/11/18)
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- Synthesis of hydrogen-substituted graphdiynes via dehalogenative homocoupling reactions
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A new method is introduced to prepare hydrogen-substituted graphdiynes (HsGDYs) via the dehalogenative homocoupling of terminal alkynyl bromides. Compared with previous synthetic strategies, the reaction conditions are moderate and the time is shortened. HsGDYs exhibit porous structures and hydrogen/oxygen evolution reaction (HER/OER) catalytic activity, endowing applications in electrochemical catalysis.
- Wu, Jiasheng,Liang, Jizhe,Zhang, Yijie,Zhao, Xiaoli,Yuan, Chunxue
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supporting information
p. 5036 - 5039
(2021/05/28)
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- An efficient nanocluster catalyst for Sonogashira reaction
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Pd together with CuI has been well known as the catalyst towards Sonogashira reaction, which provides an effective route to functional alkynes. However, the achievement of high activity and selectivity of this catalytic system is still challenging in some cases. Illustrative examples include their low activity for aryl chloride substrates, and switched selectivity to oxidative coupling products in air atmosphere. In this work, a Cu-incorporated Au13 nanocluster [Au13Cu2(PPh3)6(SC2H4Ph)6]+[NO3]- (Au13Cu2) was designed and prepared in high yield via rapid synthesis. This atomically precise nanocluster shows the potential to be a novel catalytic system for Sonogashira reaction, featuring high activity and selectivity, as well as good recyclability even in air atmosphere.
- Chen, Cheng,Chen, Li,Li, Man-Bo,Luo, Gen,Lv, Qi-Long,Wu, Zhikun,Xu, Guo-Yong,Yang, Jinlong,Yang, Ying,Ye, Sun-Feng,Yuan, Jinyun
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p. 206 - 213
(2021/08/16)
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- Ligand-free Pd/Ag-mediated dehydrogenative alkynylation of imidazole derivatives
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A variety of 2-alkynyl(benzo)imidazoles have been synthesized by dehydrogenative alkynylation of (benzo)imidazoles with terminal alkyne in NMP under air in the presence of Ag2CO3as the oxidant and Pd(OAc)2as the catalyst precursor. The data obtained in this study support a reaction mechanism involving a non-concerted metalation deprotonation (n-CMD) pathway.
- Bellina, Fabio,Biagetti, Matteo,Fausti, Mattia,Guariento, Sara,Lessi, Marco,Ronchi, Paolo,Rosadoni, Elisabetta
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p. 25504 - 25509
(2021/08/03)
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- Glycosyl Triazole Ligand for Temperature-Dependent Competitive Reactions of Cu-Catalyzed Sonogashira Coupling and Glaser Coupling
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Glycosyl triazoles have been introduced as efficient ligands for the Cu-catalyzed Sonogashira reaction to overcome the challenges of sideways homocoupling reactions in Cu catalysis in this reaction. The atmospheric oxygen in a sealed tube did not affect t
- Mishra, Nidhi,Singh, Sumit K.,Singh, Anoop S.,Agrahari, Anand K.,Tiwari, Vinod K.
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p. 17884 - 17895
(2021/12/17)
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- Leaf-like CuO nanosheets on rGO as an efficient heterogeneous catalyst for Csp-Csp homocoupling of terminal alkynes
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In this work, the economic and well-defined leaf-like CuO nanosheets on rGO (CuO nanosheets/rGO) was synthesized by a convenient hydrothermal method. The morphology and chemical composition of CuO nanosheets/rGO were confirmed by XRD, SEM-EDS, TEM, HR-TEM, and XPS techniques. The CuO nanosheets/rGO was successfully applied as a high-performance heterogeneous catalyst in the homocoupling of 12 terminal alkynes, and the isolated yield of each product was more than 80%, except for propargyl alcohol. This catalyst could be reused five times with little activity loss. Thus, it is beneficial for green and sustainable development of organic synthetic chemistry.
- Gao, Lingfeng,Wang, Bin,Zheng, Gengxiu
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- Red-Light-Induced N, N'-Dipropyl-1,13-dimethoxyquinacridinium-Catalyzed [3+2] Cycloaddition of Cyclopropylamines with Alkenes or Alkynes
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A red-light-mediated [3+2] annulation of cyclopropylamines with akenes or alkynes in the presence of N,N'-dipropyl-1,13-dimethoxyquinacridinium is reported. An array of cyclopentane or cyclopentene derivatives with diverse functional groups have been obta
- Gianetti, Thomas L.,Mei, Liangyong,Stull, Savannah M.
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supporting information
(2021/11/30)
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- Synthesis, Characterization of Spirocyclic λ3-Iodanes and Their Application to Prepare 4,1-Benzoxazepine-2,5-diones and 1,3-Diynes
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Herein, a [3+2] cycloaddition of aza-oxyallylic cations with ethynylbenziodoxolones for synthesis of new λ3-iodanes containing spirocyclic 4-oxazolidinone has been developed. This cyclic λ3-iodanes display stability in air and excellent solubility in organic solvent. Using them as substrate, both the 4,1-benzoxazepine-2,5-diones and symmetrical 1,3-diynes derivatives were afforded in high yield under copper(I)-catalyzed conditions.
- Sun, Xu,Guo, Xiao-Qiang,Chen, Lian-Mei,Kang, Tai-Ran
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p. 4312 - 4316
(2021/02/06)
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- Synthesis of 1,3-Diynes Using Calcium Carbide as an Alkyne Source
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A simple method for the synthesis of 1,3-diynes from iodoarenes using calcium carbide as an alkyne source and air as an oxidant is described. A series of 1,4-diarylbuta-1,3-diynes were efficiently synthesized by this strategy. The salient features of this protocol are the use of inexpensive and easy-to-handle alkyne source, broad substrate scope, open-air condition, and simple operation procedure.
- Liu, Zhenrong,Li, Zheng
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p. 302 - 308
(2020/12/11)
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- Nickel-Catalyzed Electrochemical C(sp3)?C(sp2) Cross-Coupling Reactions of Benzyl Trifluoroborate and Organic Halides**
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Reported here is the redox neutral electrochemical C(sp2)?C(sp3) cross-coupling reaction of bench-stable aryl halides or β-bromostyrene (electrophiles) and benzylic trifluoroborates (nucleophiles) using nonprecious, bench-stable NiCl2?glyme/polypyridine catalysts in an undivided cell configuration under ambient conditions. The broad reaction scope and good yields of the Ni-catalyzed electrochemical coupling reactions were confirmed by 50 examples of aryl/β-styrenyl chloride/bromide and benzylic trifluoroborates. Potential applications were demonstrated by electrosynthesis and late-stage functionalization of pharmaceuticals and natural amino acid modification, and three reactions were run on gram-scale in a flow-cell electrolyzer. The electrochemical C?C cross-coupling reactions proceed through an unconventional radical transmetalation mechanism. This method is highly productive and expected to find wide-spread applications in organic synthesis.
- Luo, Jian,Hu, Bo,Wu, Wenda,Hu, Maowei,Liu, T. Leo
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p. 6107 - 6116
(2021/02/01)
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- P-Alkynyl functionalized benzazaphospholes as transmetalating agents
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Exposure of 10π-electron benzazaphosphole 1 to HCl, followed by nucleophilic substitution with the Grignard reagent BrMgCCPh afforded alkynyl functionalized 3 featuring an exocyclic -CC-Ph group with an elongated P-C bond (1.7932(19) ?). Stoichiometric experiments revealed that treatment of trans-Pd(PEt3)2(Ar)(i) (Ar = p-Me (C) or p-F (D)) with 3 generated trans-Pd(PEt3)2(Ar)(CCPh) (Ar = p-Me (E) or p-F (F)), 5, which is the result of ligand exchange between P-I byproduct 4 and C/D, and the reductively eliminated product (Ar-CC-Ph). Cyclic voltammetry studies showed and independent investigations confirmed 4 is also susceptible to redox processes including bimetallic oxidative addition to Pd(0) to give Pd(i) dimer 6-Pd2-(P(t-Bu)3)2 and reduction to diphosphine 7. During catalysis, we hypothesized that this unwanted reactivity could be circumvented by employing a source of fluoride as an additive. This was demonstrated by conducting a Sonogashira-type reaction between 1-iodotoluene and 3 in the presence of 10 mol% Na2PdCl4, 20 mol% P(t-Bu)Cy2, and 5 equiv. of tetramethylammonium fluoride (TMAF), resulting in turnover and the isolation of Ph-CC-(o-Tol) as the major product.
- Zhou, Daniel Y.,Miura-Akagi, Preston M.,McCarty, Sierra M.,Guiles, Celeste H.,O'Donnell, Timothy J.,Yoshida, Wesley Y.,Krause, Colleen E.,Rheingold, Arnold L.,Hughes, Russell P.,Cain, Matthew F.
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supporting information
p. 599 - 611
(2021/01/28)
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- Fritsch-Buttenberg-Wiechell rearrangement of magnesium alkylidene carbenoids leading to the formation of alkynes
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A series of 1-heteroatom-substituted vinyl p-tolyl sulfoxides were prepared and treated with organometallic reagents to evaluate which combination of sulfoxides and organometallic reagents yielded alkynes the most efficiently. The use of 1-chlorovinyl p-tolyl sulfoxide and isopropylmagnesium chloride was optimal for this purpose. A variety of 1-chlorovinyl p-tolyl sulfoxides were prepared from carbonyl compounds and chloromethyl p-tolyl sulfoxide and were converted into alkynes via the sulfoxide/magnesium exchange reaction and subsequent Fritsch-Buttenberg-Wiechell (FBW) rearrangement of the resulting magnesium alkylidene carbenoids. The mechanism of the FBW rearrangement of magnesium alkylidene carbenoids was studied by using13C-labeled sulfoxides and by using DFT calculations.
- Ando, Akane,Imafuji, Aki,Kimura, Tsutomu,Sekiguchi, Koto
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p. 1352 - 1359
(2021/06/06)
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- Harnessing in Situ Radical Oxygenation: Copper-Catalyzed Interrupted Azirine-Alkyne Ring-Expansion Reaction for the Synthesis of Pyrrolones
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Here we report a novel interrupted azirine-alkyne ring-expansion reaction with molecular oxygen for the direct synthesis of highly functionalized pyrrolones enabled by copper catalysis. Mechanistic investigations indicate that the present three-component reaction proceeds via two copper-catalyzed sequential reactions, an azirine-ring-opening alkynylation and an amine-directed radical oxygenation, leading to the formation of interesting pyrrolone structures under mild conditions.
- Sujatha, Chandragiri,Nallagangula, Madhu,Namitharan, Kayambu
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supporting information
p. 4219 - 4223
(2021/06/21)
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- Decarboxylative Addition of Propiolic Acids with Indoles to Synthesize Bis(indolyl)methane Derivatives with a Pd(II)/LA Catalyst
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Exploring new protocols for efficient organic synthesis is crucial for pharmaceutical developments. The present work introduces a Pd(II)/LA-catalyzed (LA: Lewis acid) decarboxylative addition reaction for the synthesis of bis(indolyl)methane derivatives. The presence of Lewis acid such as Sc(OTf)3 triggered Pd(II)-catalyzed decarboxylative addition of propiolic acids with indoles to offer the bis(indolyl)methane derivatives in moderate to good yields, whereas neither Pd(II) nor Lewis acid alone was active for this synthesis. The catalytic efficiency of Pd(OAc)2 was highly dependent on the Lewis acidity of the added Lewis acid, that is, a stronger Lewis acid provided a higher yield of the bis(indolyl)methane derivatives. Meanwhile, this Pd(II)/LA-catalyzed decarboxylative addition reaction showed good tolerance toward versatile electron-rich or-deficient substituents on the indole skeleton and on the benzyl ring of propiolic acids. The studies on the in situ 1H NMR kinetics of this Pd(II)/Sc(III) catalysis disclosed the formation of a transient vinyl-Pd(II)/Sc(III) intermediate generated by the pyrrole addition to the alkynyl-Pd(II)/Sc(III) species after decarboxylation, which was scarcely observed before.
- Zeng, Miao,Xue, Jing-Wen,Jiang, Hongwu,Li, Kaiwen,Chen, Yunong,Chen, Zhuqi,Yin, Guochuan
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supporting information
p. 8333 - 8350
(2021/06/28)
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- Direct Photoexcitation of Ethynylbenziodoxolones: An Alternative to Photocatalysis for Alkynylation Reactions**
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Ethynylbenziodoxolones (EBXs) are commonly used as radical traps in photocatalytic alkynylations. Herein, we report that aryl-substituted EBX reagents can be directly activated by visible light irradiation. They act as both oxidants and radical traps, alleviating the need for a photocatalyst in several reported EBX-mediated processes, including decarboxylative and deboronative alkynylations, the oxyalkynylation of enamides and the C?H alkynylation of THF. Furthermore, the method could be applied to the synthesis of alkynylated quaternary centers from tertiary alcohols via stable oxalate salts and from tertiary amines via aryl imines. A photocatalytic process using 4CzIPN as an organic dye was also developed for the deoxyalkynylation of oxalates.
- Amos, Stephanie G. E.,Cavalli, Diana,Le Vaillant, Franck,Waser, Jerome
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p. 23827 - 23834
(2021/09/25)
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- Direct growth of crystalline triazine-based graphdiyne using surface-assisted deprotection-polymerisation
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Graphdiyne polymers have interesting electronic properties due to their π-conjugated structure and modular composition. Most of the known synthetic pathways for graphdiyne polymers yield amorphous solids because the irreversible formation of carbon-carbon bonds proceeds under kinetic control and because of defects introduced by the inherent chemical lability of terminal alkyne bonds in the monomers. Here, we present a one-pot surface-assisted deprotection/polymerisation protocol for the synthesis of crystalline graphdiynes over a copper surface starting with stable trimethylsilylated alkyne monomers. In comparison to conventional polymerisation protocols, our method yields large-area crystalline thin graphdiyne films and, at the same time, minimises detrimental effects on the monomers like oxidation or cyclotrimerisation side reactions typically associated with terminal alkynes. A detailed study of the reaction mechanism reveals that the deprotection and polymerisation of the monomer is promoted by Cu(ii) oxide/hydroxide species on the as-received copper surface. These findings pave the way for the scalable synthesis of crystalline graphdiyne-based materials as cohesive thin films.
- Amsalem, Patrick,Bojdys, Michael J.,Burmeister, David,Huang, Jieyang,Kass, Dustin,Koch, Norbert,Kulkarni, Ranjit,Müller, Johannes,Martin, Andréa,Trunk, Matthias
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p. 12661 - 12666
(2021/10/19)
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- In Situ Synthesis of CuN4/Mesoporous N-Doped Carbon for Selective Oxidative Crosscoupling of Terminal Alkynes under Mild Conditions
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The 1,3-conjugated diynes are an important class of chemical intermediates, and the selective crosscoupling of terminal alkynes is an efficient chemical process for manufacturing asymmetrical 1,3-conjugated diynes. However, it often occurs in homogenous conditions and costs a lot for reaction treatment. Herein, a copper catalyzed strategy is used to synthesize highly ordered mesoporous nitrogen-doped carbon material (OMNC), and the copper species is in situ transformed into the copper single-atom site with four nitrogen coordination (CuN4). These features make the CuN4/OMNC catalyst efficient for selective oxidative crosscoupling of terminal alkynes, and a wide range of asymmetrical and symmetrical 1,3-diynes (26 examples) under mild conditions (40?°C) and low substrates ratio (1.3). Density functional theory (DFT) calculations reveal that the aryl–alkyl crosscoupling has the lowest energy barrier on the CuN4 site, which can explain the high selectivity. In addition, the catalyst can be separated and reused by simply centrifugation or filtration. This work can open a facile avenue for constructing single-atom loaded mesoporous materials to bridge homogeneous and heterogeneous catalysis.
- Cao, Yue,Gu, Dong,Lei, Aiwen,Liang, Zhenjin,Su, Yaqiong,Wu, Jinsong,Wu, Yong,Xiao, Wei,Yang, Dali,Yu, Ruohan,Zhang, Dongchao,Zhang, Yuanteng
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- Visible-Light-Induced Photocatalytic Oxidative Decarboxylation of Cinnamic Acids to 1,2-Diketones
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A concerted metallophotoredox catalysis has been realized for the efficient decarboxylative functionalization of α,β-unsaturated carboxylic acids with aryl iodides in the presence of perylene bisimide dye to afford 1,2-diketones.
- Chand, Shiv,Pandey, Anand Kumar,Singh, Rahul,Singh, Krishna Nand
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p. 6486 - 6493
(2021/05/06)
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- Polymer Beads Decorated with Dendritic Systems as Supports for A3 Coupling Catalysts
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Abstract: The gel type microscopic polymer beads bearing epoxy functionalities were modified using the two-stage procedures in order to decorate their surface with the moieties of the zeroth order PAMAM type dendrimer and different heterocyclic aldehydes (2-pyridinecarboxaldehyde, 2-pyrrolidinecarboxaldehyde, furfural or 2-thiophenecarboxaldehyde). The polymeric supports provided in this manner were then used for the immobilization of copper(II) ions. The resulting materials were characterized using different instrumental techniques (optical microscopy, SEM, FTIR microscopy, DR UV–Vis, ICP-OES, and thermal analysis). They were also used?as catalysts in the model A3 coupling reaction of benzaldehyde, morpholine and phenylacetylene. The best catalytic activity was found for the polymeric catalyst bearing 2-pyridinecarboxaldehyde moieties. It turned out to be effective in the A3 coupling reactions included different benzaldehyde, alkyne, and secondary amine derivatives, as well. It could also be recycled several times without a significant decrease in its activity in the model A3 coupling reaction. Graphic Abstract: [Figure not available: see fulltext.]
- Bukowska, Agnieszka,Bester, Karol,Pytel, Maciej,Bukowski, Wiktor
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p. 422 - 434
(2020/07/13)
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- Enabling the Use of Alkyl Thianthrenium Salts in Cross-Coupling Reactions by Copper Catalysis
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Alkyl groups are one of the most widely used groups in organic synthesis. Here, a a series of thianthrenium salts have been synthesized that act as reliable alkylation reagents and readily engage in copper-catalyzed Sonogashira reactions to build C(sp3)?C(sp) bonds under mild photochemical conditions. Diverse alkyl thianthrenium salts, including methyl and disubstituted thianthrenium salts, are employed with great functional breadth, since sensitive Cl, Br, and I atoms, which are poorly tolerated in conventional approaches, are compatible. The generality of the developed alkyl reagents has also been demonstrated in copper-catalyzed Kumada reactions.
- Chen, Cheng,Lu, Hongjian,Shi, Zhuangzhi,Wang, Minyan,Zhao, Binlin
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supporting information
p. 21756 - 21760
(2021/08/30)
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- Electrochemical Palladium-Catalyzed Oxidative Sonogashira Carbonylation of Arylhydrazines and Alkynes to Ynones
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Oxidative carbonylation using carbon monoxide has evolved as an attractive tool to valuable carbonyl-containing compounds, while mixing CO with a stoichiometric amount of a chemical oxidant especially oxygen is hazardous and limits its application in scale-up synthesis. By employing anodic oxidation, we developed an electrochemical palladium-catalyzed oxidative carbonylation of arylhydrazines with alkynes, which is regarded as an alternative supplement of the carbonylative Sonogashira reaction. Combining an undivided cell with constant current mode, oxygen-free conditions avoids the explosion hazard of CO. A diversity of ynones are efficiently obtained using accessible arylhydrazines and alkynes under copper-free conditions. A possible mechanism of the electrochemical Pd(0)/Pd(II) cycle is rationalized based upon cyclic voltammetry, kinetic studies, and intermediates experiments.
- Cao, Yue,Hu, Jingcheng,Lei, Aiwen,Li, Haoran,Shi, Renyi,Wu, Yong,Xu, Minghao,Yi, Hong,Zeng, Li
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supporting information
p. 12460 - 12466
(2021/08/24)
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- Cross Coupling of Bis[(E)-2-bromovinyl)] Selenide with Terminal Acetylenes in the Presence of Pd(PPh3)4: the First Example of the Sonogashira Cross Coupling Involving Vinyl Selenide
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Abstract: Bis[(E)-2-bromovinyl] selenide enters cross coupling with terminal acetylenes in the presence of a Pd/CuI catalyst at room temperature. The reaction involves both the bromine atom and the selanyl function and leads to both substituted bis(but-1-
- Amosova, S. V.,Makhaeva, N. A.,Martynov, A. V.,Musalov, M. V.
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p. 1882 - 1886
(2021/12/22)
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- Transition-metal-free variant of Glaser- and Cadiot-Chodkiewicz-type Coupling: Benign access to diverse 1,3-diynes and related molecules
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Efficient and transition-metal-free transformations towards the synthesis of 1,3-diynes have been described from their corresponding terminal acetylenes or 1,1-dibromo-1-alkenes. The efficiency of molecular iodine as catalyst in aqueous medium, driven the transformation to afford 1,3-diynes in moderate to good yields. The developed reaction conditions revealed appreciable functional group tolerance in aqueous medium. Further, the scope of the transition-metal-free approach for the synthesis of 1,3-enynes has been investigated using terminal alkynes as easy available precursors.
- Kaldhi, Dhananjaya,Vodnala, Nagaraju,Gujjarappa, Raghuram,Kabi, Arup K.,Nayak, Subhashree,Malakar, Chandi C.
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- Oxidative Addition of Alkenyl and Alkynyl Iodides to a AuI Complex
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The first isolated examples of intermolecular oxidative addition of alkenyl and alkynyl iodides to AuI are reported. Using a 5,5′-difluoro-2,2′-bipyridyl ligated complex, oxidative addition of geometrically defined alkenyl iodides occurs readily, reversibly and stereospecifically to give alkenyl-AuIII complexes. Conversely, reversible alkynyl iodide oxidative addition generates bimetallic complexes containing both AuIII and AuI centers. Stoichiometric studies show that both new initiation modes can form the basis for the development of C?C bond forming cross-couplings.
- Bower, John F.,Cadge, Jamie A.,Russell, Christopher A.,Sparkes, Hazel A.
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p. 6617 - 6621
(2020/03/13)
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- CuII-Catalyzed Oxidative Formation of 5-Alkynyltriazoles
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In an alcoholic solvent under the catalysis of Cu(OAc)2?H2O, organic azide and terminal alkyne could oxidatively couple to afford 5-alkynyl-1,2,3-triazole (alkynyltriazole) at room temperature under an atmosphere of O2 in a few hours. The involvement of 1,5-diazabicyclo[4.3.0]non-5-ene (DBN) is essential, without which the redox neutral coupling instead proceeds to produce 5-H-1,2,3-triazole (protiotriazole) as the major product. Therefore, DBN switches the redox neutral coupling between terminal alkyne and organic azide, the copper-catalyzed “click” reaction to afford protiotriazole, to an oxidation reaction that results in alkynyltriazole. The organic base DBN is effective in accelerating the copper(II)-catalyzed oxidation of terminal alkyne or copper(I) acetylide, which is intercepted by an organic azide to produce alkynyltriazole. The proposed mechanistic model suggests that the selectivity between alkynyl- and protiotriazole, and other acetylide or triazolide oxidation products is determined by the competition between copper(I)-catalyzed redox neutral cycloaddition and copper(II)/O2-mediated acetylide oxidation after the formation of copper(I) acetylide.
- Liu, Peiye,Brassard, Christopher J.,Lee, Justin P.,Zhu, Lei
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supporting information
p. 380 - 390
(2020/01/24)
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- Copper-catalysed three-component carboiodination of arynes: Expeditious synthesis of: O -alkynyl aryl iodides
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A copper-catalysed three-component iodoalkynylation reaction of arynes for the expeditious and versatile synthesis of o-alkynyl aryl iodides has been developed. Mechanism research shows that the reaction goes through two steps enabled by copper catalysis: the formation of 1-iodo-2-arylacetylene and the insertion of the aryne into a C(sp)-I bond.
- Cao, Wenxuan,Niu, Sheng-Li,Shuai, Li,Xiao, Qing
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supporting information
p. 972 - 975
(2020/02/03)
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- TiO2/Cu2O nanoparticle-catalyzed direct C(sp)-P bond formation: Via aerobic oxidative coupling in air and visible light
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The synthesis of organophosphorus compounds is one of the important goals in organic chemistry. Among these compounds, alkynylphosphonates are significantly utilized as the main precursors for the synthesis of biologically active molecules in medicinal chemistry and have attracted extensive interest in the past few decades. Although few efforts have been made towards the direct and atom-economical synthesis of alkynylphosphonates, efforts towards the utilization of visible light as a green and renewable energy source have not been made to date. Here, we have promoted a strategy to construct a type of nano metal oxide composite photocatalyst (Cu2O decorated on TiO2) for the synthesis of alkynylphosphonates via direct C-P bond formation between terminal alkyne and H-phosphonate under visible light irradiation. In this p-n heterojunction photocatalyst, Cu2O acted as a visible-light absorber; moreover, the CB (conduction band) of TiO2 was favorable for accepting a photogenerated electron, and the generated electron hole (e-/h+) pair could initiate the reaction. The present study can provide a new way for the synthesis of this important class of phosphorus organic compounds.
- Hosseini-Sarvari, Mona,Jafari, Fattaneh
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p. 3001 - 3006
(2020/03/13)
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- Synthesis of 8-carbo substituted 2-(trifluoromethyl)-4H-furo[2,3-h]chromen-4-ones and their thienoangelicin derivatives
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Tandem Sonogashira cross-coupling and heteroannulation of 7-hydroxy-8-iodo-2-(trifluoromethyl)chromen-4-one with terminal acetylenes afforded the 8-carbo–substituted 2-(trifluoromethyl)-4H-furo[2,3-h]chromen-4-ones 2a–i. The latter were reacted with methyl mercaptoacetate in the presence of triethylamine to afford the corresponding 7,8-dihydro-5H-furo[2,3-h]thieno[2,3-c]chromen-5-one derivatives 3a–i. The structures of the prepared compounds were characterized using a combination of NMR (1H-, 13C & 19F-), IR and mass spectroscopic techniques, and confirmed by single X-ray crystal structures of 8-(3-fluorophenyl)-2-(trifluoromethyl)-4H-furo[2,3-h]chromen-4-one (2b) and 2-phenyl-7-(trifluoromethyl)-7,8-dihydro-5H-furo[2,3-h]thieno[2,3-c]chromen-5-one (3a). The highlight of this investigation is the conversion of 2-(trifluoromethyl)–substituted 4H-furo[2,3-h]chromen-4-ones into trifluoromethyl–substituted thienoangelicin analogues.
- Olomola, Temitope O.,Mphahlele, Malose J.
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- Synthesis, α-glucosidase inhibition and antioxidant activity of the 7-carbo–substituted 5-bromo-3-methylindazoles
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Series of 7-aryl- (3a–f), 7-arylvinyl- (3g–k) and 7-(arylethynyl)-5-bromo-3-methylindazoles (4a–f) have been evaluated through enzymatic assay in vitro for inhibitory effect against α-glucosidase activity and for antioxidant potential through the 2,2-diph
- Gildenhuys, Samantha,Magwaza, Nontokozo M.,Mphahlele, Malose J.,Setshedi, Itumeleng B.
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- Palladium/copper-cocatalyzed decarbonylative alkynylation of acyl fluorides with alkynylsilanes: Synthesis of unsymmetrical diarylethynes
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Palladium/copper-cocatalyzed decarbonylative alkynylation of acyl fluorides with alkynylsilanes is described. This reaction not only effectively inhibits the formation of undesired homocoupled products by avoiding the addition of a base, but also exhibits a wide substrate scope to provide a general access to diverse unsymmetrical diarylethynes.
- Chen, Qiang,Fu, Liyan,Nishihara, Yasushi
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supporting information
p. 7977 - 7980
(2020/09/09)
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- Photoinduced Copper-Catalyzed Asymmetric Decarboxylative Alkynylation with Terminal Alkynes
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We describe a photoinduced copper-catalyzed asymmetric radical decarboxylative alkynylation of bench-stable N-hydroxyphthalimide(NHP)-type esters of racemic alkyl carboxylic acids with terminal alkynes, which provides a flexible platform for the construction of chiral C(sp3)?C(sp) bonds. Critical to the success of this process are not only the use of the copper catalyst as a dual photo- and cross-coupling catalyst but also tuning of the NHP-type esters to inhibit the facile homodimerization of the alkyl radical and terminal alkyne, respectively. Owing to the use of stable and easily available NHP-type esters, the reaction features a broader substrate scope compared with reactions using the alkyl halide counterparts, covering (hetero)benzyl-, allyl-, and aminocarbonyl-substituted carboxylic acid derivatives, and (hetero)aryl and alkyl as well as silyl alkynes, thus providing a vital complementary approach to the previously reported method.
- Dong, Xiao-Yang,Du, Xuan-Yi,Fang, Jia-Heng,Gu, Qiang-Shuai,Li, Zhong-Liang,Liu, Xin-Yuan,Wang, Li-Lei,Xia, Hai-Dong
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p. 16926 - 16932
(2020/08/25)
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- Conceptual approach to the synthesis of symmetrical 1,3-diynes from β-bromo vinyl carboxylic acids
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Abstract: A conceptual route has been developed for the synthesis of 1,3-diyne from β-bromo vinyl carboxylic acids. The reaction of the β-bromo vinyl carboxylic acid with palladium catalyst is conceptually similar to the decomposition of 2-diazoniumbenzoic acid to benzyne. In the presence of palladium catalyst, the β-bromo vinyl carboxylic acid undergoes a fragmentation to generate terminal alkyne. The terminal alkyne undergoes dimerisation in the presence of palladium catalysts to produce the product 1,3-diyne. Graphic abstract: A conceptual route has been developed for the synthesis of 1,3-diyne from β-bromo vinyl carboxylic acids. To the best of our knowledge, we are the first ones reporting the synthesis of 1,3-diyne in a catalytic way without the requirement of any prefunctionalized alkyne unit(s).[Figure not available: see fulltext.]
- Singha, Raju
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- An insight into the novel covalent functionalization of multi-wall carbon nanotubes with pseudopeptide backbones for palladium nanoparticles immobilization: A versatile catalyst towards diverse cross-coupling reactions in bio-based solvents
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Materials functionalization with multicomponent reactions (MCRs) has grabbed a lot of attention nowadays due to the integration of outstanding features of MCRs with materials domains. Herein, we put the spotlight on the isocyanides and Meldrum's acid-based MCRs route for the one-pot covalent functionalization of multi-wall carbon nanotubes (MWCNTs) which led to pseudopeptide-decorated MWCNTs with the ability to immobilized palladium nanoparticles and serve as a neoteric catalytic system. Characterization of the synthesized nanocatalyst was carried out by FT-IR, 1H NMR, XRD, SEM, TEM, EDX and TGA. The catalytic activities of the nanocatalyst for diverse carbon-carbon cross-coupling reactions were examined in bio-based solvents. The results showed the catalytic performance of the nanocatalyst for the formation of Csp2-Csp2, Csp-Csp2 and Csp-Csp bonds through homocoupling and intermolecular Ullmann, C[sbnd]H arylation, Mizoroki-Heck, Sonogashira and Glaser coupling reactions with considerable improvements in the yield, reaction times, bio-based media and chemoselectivity of the procedures. Additionally, this method demonstrated a high potential for recycling of heterogeneous catalysts by maintaining their initial performances without any evidence of the Pd leaching.
- Afshari, Ronak,Emad Hooshmand, Seyyed,Atharnezhad, Mojtaba,Shaabani, Ahmad
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- Strategy to isolate ionic gold sites on silica surface: Increasing their efficiency as catalyst for the formation of 1,3-diynes
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A new strategy is presented to obtain an efficient heterogeneous gold catalyst constituted by isolated ionic gold sites, which is known to be effective in alkyne coupling reaction. The procedure is based on a significant difference between offered gold amount and available adsorbent sites on the support, ensuring the formation of very active isolated gold ion sites. In order to achieve this purpose, mesoporous silica xerogel was grafted with an ionic silsesquioxane containing charged ammonium quaternary group. The modified silica showed 0.25 mmol of cationic sites per gram of material and presented thermal stability up to 200 °C. This material was applied as support for immobilization of Au(III) ions as square planar AuCl4? complex. The gold amount offered was just 12 % of the exchangeable capacity. The catalyst was efficiently applied in the cross coupling reactions, in which only 0.22 mol% was applied to obtain symmetric and non-symmetric 1,3-diynes.
- Didó, Cezar A.,Coelho, Felipe L.,Closs, Maurício B.,Deon, Monique,Horowitz, Flavio,Bernardi, Fabiano,Schneider, Paulo H.,Benvenutti, Edilson V.
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- Functionalization of graphene oxide sheets with magnetite nanoparticles for the adsorption of copper ions and investigation of its potential catalytic activity toward the homocoupling of alkynes under green conditions
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This paper deals with the preparation of graphene oxide sheets (GO) modified with magnetite nanoparticles (Fe3O4NPs) for removing Cu(II) ions from aqueous solutions. Moreover, the recovered Cu(II)-based material was recycled as a cat
- Baouab, Mohammed Hassen V.,Beyou, Emmanuel,Chaabane, Laroussi,Luneau, Dominique
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- Trithiocarbonate Anion as a Sulfur Source for the Synthesis of 2,5-Disubstituted Thiophenes and 2-Substituted Benzo[ b]thiophenes
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The trithiocarbonate anion (CS32-) was generated in situ from CS2 and KOH in dimethyl sulfoxide by a simple method and used as a novel synthetic equivalent of the S2- synthon for the synthesis of 2,5-disubstituted thiophenes from 1,3-butadiynes. Additionally, this system was employed for the metal-free synthesis of 2-substituted benzo[b]thiophenes from 2-haloalkynyl (hetero)arenes. These compounds were obtained from a cheap and readily available sulfur source in moderate to good yields, with good functional group tolerance.
- Paix?o, Douglas B.,Rampon, Daniel S.,Salles, Helena D.,Soares, Eduardo G. O.,Bilheri, Filipe N.,Schneider, Paulo H.
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supporting information
p. 12922 - 12934
(2020/11/26)
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- Reduced graphene oxide supported copper oxide nanocomposites: An efficient heterogeneous and reusable catalyst for the synthesis of ynones, 1,3-diynes and 1,5-benzodiazepines in one-pot under sustainable reaction conditions
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A greener and efficient method for the synthesis of ynones and 1,3-diynes using copper oxide nanoparticles (CuONPs) doped reduced graphene oxide (CuO@rGO) catalyst under palladium, ligand and solvent free conditions have been developed. The catalyst was s
- Sarkar, Rajib,Gupta, Ajay,Jamatia, Ramen,Pal, Amarta Kumar
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- Selective C-C coupling of terminal alkynes under an air atmosphere without base over Cu-NX-C catalysts
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The fabrication of a silk fibroin-drived porous, in situ nitrogenated carbon skeleton with highly dispersed Cu-NX-C active sites via a sol-gel and pyrolysis treatment was demonstrated. Cu-NX-C was used to catalyze the oxidative homo-coupling of terminal a
- Xiao, Xinxin,Xu, Yin,Bhavanarushi, Sangepu,Liu, Bin,Lv, Xiaomeng
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supporting information
p. 20993 - 20998
(2020/12/31)
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- Ruthenium-Catalyzed trans-Hydroalkynylation and trans-Chloroalkynylation of Internal Alkynes
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[Cp*RuCl]4 catalyzes the addition of iPr3SiCCX (X = H, Cl) across internal alkynes with formation of 1,3-enyne or 1-chloro-1,3-enyne derivatives, respectively; the reaction follows an unorthodox trans-addition mode. The well-balanced affinities of the different reaction partners to the ruthenium catalyst ensure that crossed addition prevails over homodimerization of the individual components, as can be deduced from spectroscopic and crystallographic data of various intermediates; this includes a dinuclear complex in which an internal alkyne bridges two [Cp*RuCl] fragments.
- Barsu, Nagaraju,Leutzsch, Markus,Fürstner, Alois
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supporting information
p. 18746 - 18752
(2020/11/13)
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- Co?MOF-74@Cu?MOF-74 Derived Bifunctional Co?C@Cu?C for One-Pot Production of 1, 4-Diphenyl-1, 3-Butadiene from Phenylacetylene
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Carbon-supported metal nanoparticles (NPs) play important roles in heterogeneous catalysis. In particular, supported bimetallic catalytic systems can be promising multifunctional catalysts for one-pot tandem/cascade reactions, in which two or more successive independent reactions are realized in one pot. In this manuscript, we report the preparation of a carbon-supported bimetallic CoCu catalytic system (Co?C@Cu?C), with Co NPs wrapped by carbon-supported Cu NPs, from the pyrolysis of a core-shell structured Co?MOF-74@Cu?MOF-74. The as-obtained Co?C@Cu?C acts as a bifunctional catalyst for the transformation of phenylacetylene to 1, 4-diphenyl-1, 3-butadiene in one pot, in which supported metallic Cu NPs and Co NPs are active for the coupling and hydrogenation reaction respectively. By tuning the reaction rates of the coupling and the hydrogenation in this tandem reaction over the Co?C@Cu?C via changing the reaction medium and the reducing agent, an efficient direct transformation of phenylacetylene to 1, 4-diphenyl-1, 3-butadiene was realized. This work not only highlights the important role of MOFs in the preparation of multifunctional carbon supported metal NPs for heterogeneous catalysis, but also demonstrates the possibility of tuning the reaction rates of different catalytic steps in a tandem reaction to realize an efficient overall reaction.
- Cai, Jingyu,Zhuang, Yuzheng,Chen, Yi,Xiao, Longqiang,Zhao, Yulai,Jiang, Xiancai,Hou, Linxi,Li, Zhaohui
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p. 6241 - 6247
(2020/10/15)
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- Palladium-catalyzed double coupling reaction of terminal alkynes with isocyanides: A direct approach to symmetrical: N -aryl dialkynylimines
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A novel and efficient one-pot synthesis of symmetrical N-aryl dialkynylimines via palladium-catalyzed and copper-promoted isocyanide insertion, cross-coupling and elimination has been developed. This method features readily available starting materials, mild reaction conditions and high atom efficiency as well as simple one-pot operation, which make this strategy highly attractive. Moreover, 2-iodobenzo[f]quinoline derivatives can be obtained via electrophilic cyclization of N-aryl dialkynylimines.
- He, Yan,Liu, Li-Qiu,Wang, Ying-Chun,Xi, Zhi-Wei
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supporting information
p. 8089 - 8093
(2020/11/03)
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- One-pot Tandem Heck alkynylation/cyclization reactions catalyzed by Bis(Pyrrolyl)pyridine based palladium pincer complexes
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Ligand assisted palladium catalyzed one-pot tandem Heck alkynylation/cyclization reactions for the synthesis of benzofurans was reported in this paper. Well-defined palladium-pincer complexes exhibited excellent catalytic activities for the one-pot tandem Heck alkynylation/cyclization reactions yielding benzofuran derivatives using 0.1 molpercent catalyst. All the catalytic reactions are performed in air. The effects of variables such as solvents, the temperature on the catalytic activity are also reported. High product conversion was obtained for differently substituted 2-iodophenol at 120 °C in 10 h.
- Yadav, Seema,Dash, Chandrakanta
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- Tuning of cross-Glaser products mediated by substrate-catalyst polymeric backbone interactions
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Tuning of cross-Glaser products using different polymeric backbones supported by copper oxide nano-catalysts has been demonstrated by tweaking the substrate-catalyst interactions under greener conditions. Further, highly reactive magnetically separable and recyclable catalyst with scalability is demonstrated.
- Ali, Md. Ehesan,Dar, Arif Hassan,Gowri, Vijayendran,Jayamurugan, Govindasamy,Kaur, Sharanjeet,Mukhopadhyaya, Aritra,Neethu, K. M.,Sartaliya, Shaifali,Selim, Abdul
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supporting information
p. 2582 - 2585
(2020/03/10)
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- Ligand-Free and Recyclable Palladium(II) Acetate Catalyzes the Decarboxylative Cross-Coupling of Alkynyl Carboxylic Acids with Arylboronic Acids in Aqueous PEG-400
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A novel and ligand-free method was developed for the decarboxylative cross-coupling of alkynylcarboxylic acids with arylboronic acids. By using an environmentally friendly H 2 O-poly(ethylene glycol) (PEG-400) system as the reaction medium, a series of internal alkynes were synthesized in good yields and with remarkable selectivity. The Pd(OAc) 2-H 2 O-PEG-400 catalytic system could be used for up to three cycles without any loss of activity, demonstrating the robustness of the approach.
- Chen, Ying,Hu, Min,Tang, Bo-Xiao,Wang, Yi-Hua,Wen, Qi-Qi,Xie, Bao-Xing,Yang, Shi-Yao,Zhong, Hai-Qing,Zou, Hong
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p. 793 - 796
(2020/05/19)
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