cas 5172-02-1, 1-CHLORO-4-(PHENYLETHYNYL)BENZENE 98

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One-pot Sonogashira–Hydroarylation reaction catalyzed by anionic palladium complexes in an aqueous medium
It was found that anionic Pd(II) complexes of type [CA]2[PdCl4] and [CA]2[Pd2Cl6] (CA = imidazolium or pyridinium cation) are effective catalysts for copper-free Sonogashira coupling in an aqueous med
Dziadas, M.,Trzeciak, A. M.,Wójcik, E.
supporting information

(2022/01/26)

A facile protocol for copper-free palladium-catalyzed Sonogashira coupling in aqueous media
The combination of a readily available palladium catalyst and an eco-friendly basic aqueous solution of room-temperature ionic liquid, choline hydroxide (ChOH), was used in a facile protocol alternative to the Sonogashira coupling reaction, alkynylation of aryl halides in the absence of a copper cocatalyst and an external base. The dual nature of ChOH to act as a base and a green solvent played a crucial role in the catalytic cycle. The coupling reaction progressed efficiently to form a Csp-Csp2 bond under the identified conditions although the reaction outcome depended significantly on the substrates.
Jung, Da-Young,Park, Soo Youl,Kim, Seung-Hoi
supporting information
p. 110 - 116
(2021/11/09)

Co3O4 nanoparticles embedded in triple-shelled graphitic carbon nitride (Co3O4/TSCN): a new sustainable and high-performance hierarchical catalyst for the Pd/Cu-free Sonogashira–Hagihara cross-coupling reaction
Inspired by the synthesis of triple-shelled periodic mesoporous organosilica hollow spheres, a straightforward and controllable approach for the preparation of Co3O4 NPs embedded in triple-shelled graphitic carbon nitride has been es
Ghodsinia, Sara S. E.,Akhlaghinia, Batool,Jahanshahi, Roya
p. 3217 - 3244
(2021/05/17)

Facile one-pot synthesis of diarylacetylenes from arylaldehydes: Via an addition-double elimination process
A practical one-pot protocol has been developed to synthesize diarylacetylenes from arylaldehydes by treatment with 1-(arylmethyl)benzotriazoles and LiN(SiMe3)2. The reaction proceeded through imine formation, Mannich-type addition and double elimination to deliver products in up to 99% yields with broad substrate scope. In addition, gram-scale synthesis of 1-bromo-4-(phenylethynyl)benzene has been demonstrated.
Chen, Jianyang,Zhang, Xuan,Wu, Jiajun,Wang, Rui,Lei, Chunlin,An, Yanan
p. 4701 - 4705
(2021/06/11)

Decarbonylative Sonogashira Cross-Coupling of Carboxylic Acids
Decarbonylative Sonogashira cross-coupling of carboxylic acids by palladium catalysis is presented. The carboxylic acid is activated in situ by the formation of a mixed anhydride and further decarbonylates using the Pd(OAc)2/Xantphos system to provide an aryl-Pd intermediate, which is intercepted by alkynes to access the traditional Pd(0)/(II) cycle using carboxylic acids as ubiquitous and orthogonal electrophilic cross-coupling partners. The methodology efficiently constructs new C(sp2)-C(sp) bonds and can be applied to the derivatization of pharmaceuticals. Mechanistic studies give support to decarbonylation preceding transmetalation in this process.
Liu, Chengwei,Szostak, Michal
supporting information
p. 4726 - 4730
(2021/06/28)

Palladium-catalyzed decarbonylative sonogashira coupling of terminal alkynes with carboxylic acids
A direct decarbonylative Sonogashira coupling of terminal alkynes with carboxylic acids was achieved through palladium catalysis. This reaction did not use overstoichiometric oxidants, thus overcoming the homocoupling issue of terminal alkynes. Under the reaction conditions, a wide range of carboxylic acids including those bioactive ones could couple readily with various terminal alkynes, thus providing a relative general method for preparing internal alkynes.
Chen, Tieqiao,Huang, Tianzeng,Li, Chunya,Li, Wenhui,Li, Xinyi,Li, Zhaohui,Liu, Long,Tang, Zhi,Zhang, Tao
supporting information
p. 3304 - 3309
(2021/05/31)

Ligand-Promoted Alkynylation of Aryl Ketones: A Practical Tool for Structural Diversity in Drugs and Natural Products
Conversion of the numerous aryl ketones into aryl electrophiles via Ar-C(O) cleavage remains a challenging yet highly desirable transformation in Sonogashira-type coupling. Herein, we report a palladium-catalyzed ligand-promoted alkynylation of unstrained aryl ketones. The protocol allows the alkynylation to be carried out in a one-pot procedure with broad functional-group tolerance and substrate scope. The potential applications of this protocol in drug discovery and chemical biology are further demonstrated by late-stage diversification of a number of pharmaceuticals and natural products. More importantly, two different biologically important fragments derived from a pharmaceutical and natural product could be connected by the consecutive alkynylation of ketones. Distinct from aryl halides in conventional Sonogashira reactions, the protocol provides a practical tool for the 1,2-bifunctionalization of aryl ketone by merging ketone-directed ortho-C-H activation with ligand-promoted ipso-Ar-C(O) alkynylation.
Xu, Hui,Ma, Biao,Fu, Zunyun,Li, Han-Yuan,Wang, Xing,Wang, Zhen-Yu,Li, Ling-Jun,Cheng, Tai-Jin,Zheng, Mingyue,Dai, Hui-Xiong
p. 1758 - 1764
(2021/02/09)

Simple and efficient diaryl alkyne synthesis method
The embodiment of the invention discloses a simple and efficient diaryl alkyne synthesis method. The method comprises the steps of by taking arylmethylbenzotriazole and aromatic aldehyde as raw materials, carrying out addition and double-beta-elimination reaction under the action of bis (trimethylsilyl) amino salt MN (SiMe3) 2 to synthesize diaryl alkyne by a one-pot method. The raw materials and chemical reagents used in the method are easy to obtain, the reaction conditions are mild, the operation is simple, the substrate universality is good, the product yield is high, and the method is a simple and efficient diaryl alkyne synthesis method.
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Paragraph 0026; 0029-0031

(2021/04/14)

Ligand-free (: Z)-selective transfer semihydrogenation of alkynes catalyzed by in situ generated oxidizable copper nanoparticles
Herein, we present (Z)-selective transfer semihydrogenation of alkynes based on in situ generated CuNPs in the presence of hydrogen donors, such as ammonia-borane and a green protic solvent. This environmentally friendly method is characterized by operational simplicity combined with high stereo- and chemoselectivity and functional group compatibility. Auto-oxidation of CuNPs after the completion of a semihydrogenation reaction results in the formation of a water-soluble ammonia complex, so that the catalyst may be reused several times by simple phase-separation with no need for any special regeneration processes. Formed NH4B(OR)4 can be easily transformed back into ammonia-borane or into boric acid. In addition, a one-pot tandem sequence involving a Suzuki reaction followed by semihydrogenation was presented, which allows minimization of chemical waste production.
Grela, Karol,Kusy, Rafa?
supporting information
p. 5494 - 5502
(2021/08/16)

Selective Phosphoranation of Unactivated Alkynes with Phosphonium Cation to Achieve Isoquinoline Synthesis
We herein develop a selective phosphoranation of alkynes with phosphonium cation, which directs a concise approach to isoquinolines from unactivated alkyne and nitrile feedstocks in a single step. Mechanistic studies suggest that the annulation reaction is initiated by the unprecedented phosphoranation of alkynes, thus representing a unique reaction pattern of phosphonium salts and distinguishing it from existing protocols that largely rely on the utilization of highly functionalized imines/oximes and/or highly polarized alkynes.
Cui, Hong,Bai, Jinku,Ai, Tianyu,Zhan, Ye,Li, Guanzhong,Rao, Honghua
supporting information
p. 4023 - 4028
(2021/05/26)

Highly efficient synthesis of 1,2-disubstituted acetylenes derivatives from the cross-coupling reactions of 1-bromoalkynes with organotitanium reagents
A Highly efficient route for the synthesis of 1,2-disubstituted acetylene derivatives has been developed by nickel catalyzed cross-couplings of alkynyl halides with aryl titanium reagents under mild conditions. This has given corresponding cross-coupling products good to excellent isolated yields of up to 92 %. The aryls bearing electron-donating or electron-withdrawing groups in either alkynylhalides or aryltitanium substrates gave cross-coupling products good yields. This process was simple and easily performed, which provides an efficient method for the synthesis of 1,2-disubstituted acetylenes derivatives.
Li, Qing-Han,Wu, Chuan
supporting information

(2021/08/25)

Fluorinated Azobenzenes Switchable with Red Light
Molecular photoswitches triggered with red or NIR light are optimal for photomodulation of complex biological systems, including efficient penetration of the human body for therapeutic purposes (“therapeutic window”). Yet, they are rarely reported, and ev
Leistner, Anna-Lena,Kirchner, Susanne,Karcher, Johannes,Bantle, Tobias,Schulte, Mariam L.,G?dtel, Peter,Fengler, Christian,Pianowski, Zbigniew L.
p. 8094 - 8099
(2021/04/22)

Introduction of a Recyclable Basic Ionic Solvent with Bis-(NHC) Ligand Property and The Possibility of Immobilization on Magnetite for Ligand- and Base-Free Pd-Catalyzed Heck, Suzuki and Sonogashira Cross-Coupling Reactions in Water
A new versatile and recyclable NHC ligand precursor has been developed with ligand, base, and solvent functionalities for the efficient Pd-catalyzed Heck, Suzuki and Sonogashira cross-coupling reactions under mild conditions. Furthermore, NHC ligand precursor was immobilized on magnetite and its catalytic activity was also evaluated towards the coupling reactions as a heterogeneous catalyst. The NHC ligand precursor was prepared with imidazolium functionalization of TCT followed by a simple ion exchange by hydroxide ions. However, the results revealed an excellent catalytic activity for the both homogeneous and heterogeneous catalytic systems. 1.52?g.cm?3 and 1194 cP was obtained for the density and viscosity of the NHC ligand precursor respectively. On the other hand, the heterogeneous type could be readily recovered from the reaction mixture and reused for several times while preserving its properties. Heterogeneous nature of the magnetic catalyst was studied by hot filtration, mercury poisoning, and three-phase tests. High to excellent yields were obtained for all entries for the both homogeneous and heterogeneous catalysts, which reflects the high consistency of the catalyst. Graphic Abstract: [Figure not available: see fulltext.]
Min, Qingwang,Miao, Penghua,Chu, Deyu,Liu, Jinghan,Qi, Meijuan,Kazemnejadi, Milad
p. 3030 - 3047
(2021/02/16)

Immobilized Pd on a NHC-functionalized metal-organic FrameworkMIL-101(Cr): An efficient heterogeneous catalyst in the heck and copper-free Sonogashira coupling reactions
A heterogeneous palladium catalyst system based on immobilization of palladium moieties on a N-heterocyclic carbene (NHC) modified metal organic framework (MOF) was developed for the Heck and copper-free Sonogashira coupling reactions. In order to prepare this catalyst system, first, MIL-101(Cr) was functionalized with NHC moieties through a post synthetic modification (PSM) approach, and then Pd metal was stabilized on the prepered MIL-101(Cr)-NHC substrate. This material was characterized using various microscopic and spectroscopic techniques and then was used as an efficient heterogeneous Pd catalyst system in the Heck and copper-free Sonogashira reactions. Results of the heterogeneity tests showed that the Pd-NHC-MIL-101(Cr) catalyst can efficiently catalyzed these coupling reactions heterogeneously and no remarkable changes observed in the morphology and structure of MIL-101(Cr) template during the reaction progress. Also, existence of palladium nanoparticles immobilized on the MOF structure affirmed by the TEM and XPS analysis confirmed the oxidation state of Pd. A variety of alkene and alkyne derivatives were synthesized in good to excellent yields using this heterogeneous Pd catalyst system under normal conditions. More importantly Pd-NHC-MIL-101(Cr) catalyst was simply recovered from the reaction medium without remarkable decreasing in its catalytic activities after five times of reusability. The ICP analysis showed the very low Pd and Cr metals leaching, representing high stability and applicability of this catalyst in Pd coupling reactions.
Niknam, Esmaeil,Panahi, Farhad,Khalafi-Nezhad, Ali
supporting information

(2021/01/12)

A new approach to large scale production of dimethyl sulfone: A promising and strong recyclable solvent for ligand-free Cu-catalyzed C-C cross-coupling reactions
Dimethyl sulfone (DMSN) was easily prepared through efficient oxidation of dimethyl sulfoxide (DMSO) and used as a strong and green solvent for organic reactions. A mixture of HNO3/NaOCl was used as an oxidizing agent for efficient oxidation of DMSO to DMSN. The effect of DMSN was evaluated for copper-catalyzed coupling reactions. It is worth noting that DMSN could play the role of a ligand for copper ions. A general survey was accomplished for various types of C-C cross-coupling reactions catalyzed by CuI in DMSN in the absence of any ligand. Moderate to good yields were achieved for Sonogashira, Heck, and Suzuki cross-coupling reactions. Finally, DMSN was recovered and reused for several consecutive runs without any loss of its activity.
Cheng, Shen,Wei, Wei,Zhang, Xingyu,Yu, Hewei,Huang, Mingming,Kazemnejadi, Milad
p. 2069 - 2076
(2020/04/07)

A series of (NHC)Pd(N?O)(OAc) complexes: synthesis, characterization and catalytic activities towards desulfinative Sonogashira coupling of arylsulfonyl hydrazides with arylalkynes
A series of well-defined N-heterocyclic carbene palladium (II) complexes with general formula (NHC)Pd(N?O)(OAc) were prepared through reaction of Pd (NHC)(OAc)2(H2O) with 1-methyl-1H-pyrazole-3-carboxylic acid or 1-methyl-1H-indazole-3-carboxylic acid in the presence of K2CO3. These complexes were then used for desulfinative Sonogashira coupling of arylsulfonyl hydrazides with terminal alkynes. With low catalyst loading, all synthesized palladium compounds exhibited moderate to high catalytic activities for the reactions.
Lu, Jian-Zhong,Wang, Tian,Yang, Jin,Zhao, Ya-Yu,Zhu, Guang-Hao
(2020/02/11)

Ligand-Free and Recyclable Palladium(II) Acetate Catalyzes the Decarboxylative Cross-Coupling of Alkynyl Carboxylic Acids with Arylboronic Acids in Aqueous PEG-400
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
supporting information
p. 793 - 796
(2020/05/19)

Role of substituents present in bidentate ligand frame of Cu(I) catalysts on Sonogashira cross coupling reactions
Cu(I) catalysts {[Cu(L1?4)Cl(PPh3)] where L1?4 = condensed product of 2-(1-phenylhydrazinyl)-pyridine with different benzaldehydes} were synthesized and characterized by 1H NMR, 31P NMR, UV–Vis and IR techniques. Complex 2 structure was authenticated by single crystal X-ray method. Different electron donating and withdrawing substituents are present in the ligand frame of Cu(I) catalysts and their role on Sonogashira reaction was investigated. The efficiency order of catalysts for the coupling reaction was found to be 2 > 1>3 > 4, clearly indicated the role of substituents present in the ligand frame was useful to effectively catalyze the Sonogashira reaction. The products were characterized using 1H NMR and 13C NMR.
Chaudhary, Virendra Kumar,Dhara, Ashish Kumar,Ghosh, Kaushik,Kumari, Sheela,Mawai, Kiran,Mohanty, Aurobinda,Ratnam, Anand
(2020/10/20)

Cu2O Nanocrystals-Catalyzed Photoredox Sonogashira Coupling of Terminal Alkynes and Arylhalides Enhanced by CO2
Herein the first visible-light-activated Sonogashira C?C coupling reaction at room temperature catalyzed by single-metal heterogeneous Cu2O truncated nanocubes (Cu2O TNCs) was developed. A wide variety of aryl halides and terminal alkynes worked well in this recyclable heterogeneous photochemical process to form the corresponding Sonogashira C?C coupling products in good yields. Mechanistic control studies indicated that CO2 enhances the formation of light-absorbing heterogeneous surface-bound CuI-phenylacetylide (λmax=472 nm), which further undergoes single-electron transfer with aryl iodides/bromides to enable Sonogashira Csp2 ?Csp bond formation. In contrast to literature-reported bimetallic TiO2-containing nanoparticles as photocatalyst, this work avoided the need of cocatalysis by TiO2. Single-metal CuI in Cu2O TNCs was solely responsible for the observed Csp2 ?Csp coupling reactions under CO2 atmosphere.
Shanmugam, Munusamy,Sagadevan, Arunachalam,Charpe, Vaibhav Pramod,Pampana, V. Kishore Kumar,Hwang, Kuo Chu
p. 287 - 292
(2019/11/05)

Palladium/copper-cocatalyzed decarbonylative alkynylation of acyl fluorides with alkynylsilanes: Synthesis of unsymmetrical diarylethynes
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
supporting information
p. 7977 - 7980
(2020/09/09)

PALLADIUM ACYCLIC DIAMINOCARBENE COMPLEXES AS PRECATALYSTS FOR HIYAMA COUPLING AND THE TANDEM ONE-POT FLUORIDE FREE HIYAMA COUPLING/CYCLIZATION FOR THE SYNTHESIS OF BIOLOGICALLY RELEVANT
The present invention provides Acyclic diaminocarbene complex of formula (I): Wherein, M is palladium; X is monoanionic ligand selected from Cl, Br or I; Where R1 is different from R2; R1 is selected from the group consisting of alkyl or aryl, each of which have 4 to 20 carbon atoms, and may optionally contain one or more heteroatoms; R2 is selected from the group consisting of alkyl, or aryl each of which have 4 to 20 carbon atoms, and may optionally contain one or more heteroatoms. The said palladium diamino carbine complex of the present invention are particularly useful as catalyst from Hiyama cross-coupling reaction.
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Paragraph 0090-0091; 0102-0103

(2020/05/06)

Diorganyl tellurides as substrates in Sonogashira coupling reactions under mild conditions
A new method of Sonogashira coupling reactions between diorganyl tellurides and terminal alkynes is reported. The coupling reactions are performed using Pd(dppf)Cl2 as a catalyst, CuI as a co-catalyst in the presence of K2CO3 in DMSO. The reactions are carried out at room temperature and completed within 2 h when phenyl acetylene is used as a terminal alkyne. For aliphatic terminal alkynes, such as 1-hexyne and 1-octyne, an elevated temperature and longer reaction time are needed for the completion of the reactions. This process results in good yields of Sonogashira coupling products which is applicable for diaryl, divinyl and dialkynyl tellurides but not applicable for dialkyl tellurides.
Zhang, Shaozhong,Ailneni, Chandra,Al-Mohammed Baqer, Osamah,Lolla, Mahati,Mannava, Bala Bharathi,Siraswal, Parvinlal,Yen, Changchi,Jin, Jin
supporting information
p. 217 - 225
(2019/11/22)

Pd/Cu-free Heck and Sonogashira coupling reactions applying cobalt nanoparticles supported on multifunctional porous organic hybrid
A new heterogeneous cobalt catalyst has been synthesized by immobilizing Co species onto a nitrogen-rich porous organic polymer (Co@imine-POP). The heterogeneous catalyst synthesized was efficient in Heck and Sonogashira cross-coupling reactions in green media under mild reaction conditions without inert air and phase transfer agents. This phosphine-, copper-, and palladium-free catalyst was stable under the reaction conditions and could be reused for at least eight successive runs without a discernible decrease in its catalytic activity.
Hajipour, Abdol R.,Khorsandi, Zahra
(2020/02/11)

Palladium(II)-Catalyzed Oxidative Decarboxylative [2 + 2 + 1] Annulation of Cinnamic Acids with Alkynes: Access to Polysubstituted Pentafulvenes
An unprecedented palladium(II)-catalyzed oxidative decarboxylative [2 + 2 + 1] annulation of cinnamic acids with alkynes has been developed for the synthesis of polysubstituted pentafulvenes. Ag2CO3 and DMSO are essential for the reaction. This protocol features readily available starting materials, a wide substrate scope, and moderate to excellent yields. Moreover, various significant frameworks can be easily obtained from the late-stage transformations of pentafulvenes via oxidation, reduction, and Scholl-type reaction.
Peng, Shiyong,Chen, Nuan,Zhang, Hong,He, Min,Li, Hongguang,Lang, Ming,Wang, Jian
supporting information
p. 5589 - 5593
(2020/07/08)

Facile Access to Diverse Libraries of Internal Alkynes via Sequential Iododediazoniation/Decarboxylative Sonogashira Reaction in Imidazolium ILs without Ligand or Additive
Convenient access to diverse libraries of internal alkynes via decarboxylative Sonogashira reaction of alkynyl-carboxylic acids with iodoarenes, employing imidazolium-ILs as solvent, along with piperidine-appended imidazolium [PAIM][NTf2] as task-specific basic IL is demonstrated, without the need for any ligand or additive. The feasibility to perform these reactions by sequential one-pot iododediazoniation/decarboxylative Sonogashira reaction is also shown, and the scope of the methods is underscored by providing 29 examples. The potential for recycling and reuse of the IL solvent is also examined.
Prabhala, Pavankumar,Savanur, Hemantkumar M.,Kalkhambkar, Rajesh G.,Laali, Kenneth K.
supporting information
p. 2061 - 2064
(2019/03/07)

1-Aryltriazenes in the Suzuki, Heck, and Sonogashira Reactions in Imidazolium-ILs, with [BMIM(SO3H)][OTf] or Sc(OTf)3 as Promoter, and Pd(OAc)2 or NiCl2·glyme as Catalyst
1-Aryltriazenes, the protected and more stable form of aryl-diazonium species, can be conveniently unmasked with Br?nsted acidic-IL or Sc(OTf)3 and coupled with a host of aryl/heteroaryl boronic acids, styrenes, and aryl/alkyl acetylenes in the Suzuki, Heck and Sonogashira reactions in one-pot and in respectable isolated yields, by using palladium or nickel catalyst in readily available imidazolium ILs as solvent, under mild conditions. The scope of these reactions are explored, and the potential for recovery/reuse of the IL solvent is also addressed.
Sutar, Suraj M.,Savanur, Hemantkumar M.,Malunavar, Shruti S.,Prabhala, Pavankumar,Kalkhambkar, Rajesh G.,Laali, Kenneth K.
supporting information
p. 6088 - 6093
(2019/09/17)

Involving Single-Atom Silver(0) in Selective Dehalogenation by AgF under Visible-Light Irradiation
The dehalogenation-arylation and the hydrodehalogenation of various types of organic halides are selectively realized using AgF and visible light without any organic additives under mild conditions. Single-atom silver(0) (denoted as SAAg) serves as the catalytically active center, and the TOF of SAAg reaches 6000 h-1. This elusive activity of Ag is beyond that expected from its ionic, nano, or bulk forms.
Wu, Wenli,Cui, Enxin,Zhang, Yun,Zhang, Chen,Zhu, Feng,Tung, Chen-Ho,Wang, Yifeng
p. 6335 - 6341
(2019/07/04)

Cobalt catalyzed stereodivergent semi-hydrogenation of alkynes using H2O as the hydrogen source
Cobalt-catalyzed stereodivergent semi-hydrogenation of internal alkynes to alkenes is developed. The reaction proceeded through transfer hydrogenation under mild conditions using a base metal CoI2 as the catalyst, and H2O/MeOH as the hydrogen source with Zn as the reductant. The E/Z-selectivity of the product could be switched by changing the solvent and by inclusion/exclusion of a bidentate phosphine ligand (dppe). This method provides a simple and cost effective pathway for the synthesis of 1,2-dideuterioalkenes.
Li, Kangkui,Khan, Ruhima,Zhang, Xuexin,Gao, Yang,Zhou, Yongyun,Tan, Heng,Chen, Jingchao,Fan, Baomin
supporting information
p. 5663 - 5666
(2019/05/21)

Visible-light-initiated Sonogashira coupling reactions over CuO/TiO2 nanocomposites
CuO/TiO2 nanocomposites with different weight ratios of CuO were obtained by immersing TiO2 in aqueous solution of Cu(NO3)2, followed by heat treatment at 400 °C. The resultant CuO/TiO2 nanocomposites were fully characterized and their catalytic performance for light induced Sonogashira coupling reactions was investigated. CuO/TiO2 nanocomposites show catalytic activity for the Sonogashira coupling between aryl alkynes and aryl iodides under visible light, with optimum performance realized over the 20 wt% CuO/TiO2 nanocomposite. UV-vis DRS reveals that metal-metal charge transfer (MMCT) of Ti(iii)/Cu(ii) exists in the CuO/TiO2 nanocomposite. When irradiated, accompanied by an electron transfer from Ti(iii) to Cu(ii), the Ti(iii)/Cu(ii) moiety is excited to generate Ti(iv)/Cu(i). The as-formed Cu(i) coordinates with the deprotonated phenylacetylene to form copper phenylacetylide, which acts as an active intermediate for Sonogashira coupling reactions. This study not only provides an efficient method to realize Sonogashira coupling reactions under visible light, but also highlights the great potential of photocatalysis in light induced organic syntheses.
Li, Yuanyuan,Feng, Xue,Li, Zhaohui
p. 377 - 383
(2019/01/28)

Synthesis and characterization of a new poly(N–heterocyclic carbene Cu complex) immobilized on nano–silica, (CuII–NHCs)n@nSiO2, and its application as an efficient and reusable catalyst in the synthesis of benzimidazoles,
The present study describes the synthesis and characterization of a new poly(N–heterocyclic carbene Cu complex) immobilized on nano silica, (CuII–NHCs)n@nSiO2. The (CuII–NHCs)n@nSiO2 dendri
Khajehzadeh, Mostafa,Moghadam, Majid,Jamehbozorgi, Saeed
p. 173 - 189
(2018/10/21)

Conjugated mesoporous polyazobenzene–Pd(II) composite: A potential catalyst for visible-light-induced Sonogashira coupling
We herein report the direct harnessing of visible light energy by a novel semiconducting azobenzene-based colloidal porous organic polymer, B3-Azo4 amenable to post-synthetic Pd(II)-complexation for photo-induced Sonogashira coupling using polymer → metal energy transfer process. Completely mesoporous nano-sized particles of the obtained organic network manifested excellent Pd(II) coordinating ability and afforded desired catalytic products at room temperature under aerobic condition in aqueous medium. The protocol remained valid for different aromatic and aliphatic substrates as well. A possible reaction mechanism for photo-mediated Sonogashira coupling catalyzed by Pd-B3-Azo4 is also proposed.
Nath, Ipsita,Chakraborty, Jeet,Khan, Anish,Arshad, Muhammad N.,Azum, Naved,Rab, Malik A.,Asiri, Abdullah M.,Alamry, Khalid A.,Verpoort, Francis
p. 183 - 189
(2019/08/07)

Preparation method of aryl alkyne catalyzed by visible light
The invention discloses a simple and convenient method for directly synthesizing an aryl alkyne compound through photoredox catalysis. Aryl fluoroborate diazoate is used as an aryl free radical source, and different types of aryl alkyne are synthesized in situ through a decarboxylation process. A reaction has good functional group tolerability, and a simple domestic visible light source can be used for synthesizing the aryl alkyne of different functional groups under mild, neutral and transition-free metal reaction conditions.
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Paragraph 0046-0049

(2019/11/13)

A palladium catalyzed aryl alkyne preparation method
The invention discloses a palladium catalyzed aryl alkyne of the preparation method, comprises the following steps: in the catalyst, under the action of the ligand and alkali, substituted with aryl sulfonyl chloride alkynoic occurs in the organic solvent escapes suosuo the coupling reaction, after the reaction is finished after treatment to obtain the aryl alkyne. Used in the preparation method of the cheap raw material, the reaction and simple post treatment operation, at the same time, the reaction less side reaction, high yield of the product.
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Paragraph 0037; 0038; 0039

(2019/05/21)

Rate Enhancement in CAN-Promoted Pd(PPh3)2Cl2-Catalyzed Oxidative Cyclization: Synthesis of 2-Ketofuran-4-carboxylate Esters
Stoichiometric ceric ammonium nitrate (CAN) and a catalytic amount of Pd(PPh3)2Cl2 (5 mol %) can rapidly produce multisubstituted 2-ketofuran-4-carboxylate esters from 2-propargylic 1,3-ketoesters via oxidative O-cyclization reaction. Pd(PPh3)2Cl2 was found to be the crucial catalyst as its inclusion greatly enhanced the rate of the reaction and cleanly afforded the products within minutes. Over 30 substrates were successfully converted to the desired compounds in mostly moderate to good yields.
Ruengsangtongkul, Sureeporn,Chaisan, Nattawadee,Thongsornkleeb, Charnsak,Tummatorn, Jumreang,Ruchirawat, Somsak
supporting information
p. 2514 - 2517
(2019/04/30)

Functionalization of multi-walled carbon nanotubes by the baclofen drug to immobilize palladium nanoparticles and catalyze Sonogashira coupling reactions
The baclofen-MWCNTs-Pd nanocatalyst was synthesized through covalent grafting of baclofen molecules onto surface-modified carbon nanotubes and immobilizing Pd nanoparticles by the baclofen ligands. The chemical structure of the produced nanocatalyst was s
Nazari, Pooneh,Hekmati, Malak
(2019/02/25)

Green, cost-effective and efficient procedure for Heck and Sonogashira coupling reactions using palladium nanoparticles supported on functionalized Fe3O4@SiO2 by polyvinyl alcohol as a highly active, durable and reusable catalyst
A novel heterogenized organometallic catalyst was synthesized by coordinating palladium with polyvinyl alcohol-functionalized Fe3O4@SiO2 nanospheres. This novel catalyst was characterized using Fourier transform infrared spectroscopy, X-ray diffraction, transmission electron microscope, field emission scanning electron microscope, dynamic light scattering, UV–vis spectroscopy, X-ray photoelectron spectroscopy, energy dispersive X-ray analysis, thermogravimetric analysis and inductively coupled plasma analysis. The prepared palladium nanoparticles supported on polyvinyl alcohol functionalized Fe3O4@SiO2 nanoparticles were successfully applied as a magnetically recyclable catalyst in Heck and Sonogashira coupling reactions in water. They showed remarkable activity toward aryl halides (I, Br, Cl) using very low palladium loading in excellent yields and demonstrated high TONs (mmol of product per mmol of catalyst). Also, the catalyst could be magnetically separated and reused seven times without any appreciable loss of catalytic activity.
Sardarian, Ali Reza,Eslahi, Hassan,Esmaeilpour, Mohsen
(2019/05/28)

Arylation of Terminal Alkynes by Aryl Iodides Catalyzed by a Parts-per-Million Loading of Palladium Acetate
Arylation of terminal alkynes (16 varieties) by aryl iodides (28 varieties) was achieved with a mol ppm loading level of palladium catalyst, where a variety of functional groups including heteroarenes were tolerated. Thus, the arylations were carried out in the presence of palladium acetate at ppm loadings and potassium carbonate in ethanol at 80 °C to give the corresponding internal alkynes in good to excellent yields. Synthesis of 2-phenyl-3-(phenylalkynyl)benzofuran was achieved by iterative use of the alkyne arylation under mol ppm catalytic conditions. Reaction-rate analysis, transmission electron microscopic (TEM) examination of the reaction mixture, and mercury-amalgamation test were performed to gain insight into the active species of the highly active ppm catalytic species. TEM examination of the reaction mixture revealed that palladium nanoparticles were generated in situ under the reaction conditions, and their cluster size was variable during the catalytic reaction. A variation in size of palladium particles suggested that the composition-decomposition process of Pd aggregates should take place in situ via monomeric palladium(0) species and/or fine palladium(0) clusters, which might be real catalytic species in this reaction.
Hamasaka, Go,Roy, David,Tazawa, Aya,Uozumi, Yasuhiro
p. 11640 - 11646
(2019/12/02)

Imidazolium chloride-Co(iii) complex immobilized on Fe3O4@SiO2 as a highly active bifunctional nanocatalyst for the copper-, phosphine-, and base-free Heck and Sonogashira reactions
A heterogeneous, magnetically recoverable Fe3O4@SiO2@Im[Cl]Co(iii)-melamine nanocomposite was prepared by immobilization of a novel Co(iii) Schiff base complex on Fe3O4@SiO2 nanoparticles followed by treatment with melamine, and was found to be an efficient catalyst for the Heck and Sonogashira reactions. The reactions were performed in the presence of the catalyst (0.5 mol% Co) along with Mn additive in the absence of any base, phosphine ligand, or Cu/co-catalyst in ethanol under reflux conditions. The nanocatalyst was well studied by FTIR, CHN, XRD, XPS, TGA, EDX, VSM, ICP, NMR, FE-SEM, TEM, BET, CV, and DLS analyses. The catalyst was compatible with a variety of substrates, with which all the Heck and Sonogashira coupling products were obtained in high to excellent yields. Also, protocols such as hot filtration, three-phase testing, and mercury poisoning provided a complete insight into the nature of the heterogeneous catalyst. The recycling and reuse of the catalyst were studied for both coupling reactions several times. Moreover, the mechanism of the coupling reactions was entirely investigated.
Kazemnejadi, Milad,Alavi, Seyyedeh Ameneh G.,Rezazadeh, Zinat,Nasseri, Mohammad Ali,Allahresani, Ali,Esmaeilpour, Mohsen
p. 1718 - 1734
(2019/04/08)

Bis-salophen palladium complex immobilized on Fe3O4@SiO2 nanoparticles as a highly active and durable phosphine-free catalyst for Heck and copper-free Sonogashira coupling reactions
New Fe3O4@SiO2 core-shell superparamagnetic nanoparticles functionalized by a bis-salophen Schiff base Pd complex were synthesized and employed as an efficient magnetic nanocatalyst in the Heck and Sonogashira cross coupling reactions. The synthesized nanostructures were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), dynamic light scattering (DLS), energy dispersive X-ray analysis (EDX), X-ray photoelectron spectroscopy (XPS), elemental analysis (CHN), cyclic voltammetry (CV), Brunauer-Emmett-Teller analysis (BET), and UV-vis spectroscopy. The morphology and size of the nanoparticles were investigated by FE-SEM and TEM analyses. Furthermore, the magnetic properties of the catalyst were investigated by VSM analysis. The loading content and leaching amounts of palladium on the catalyst were measured by inductively coupled plasma (ICP) analysis. Also, the thermal behavior of this magnetic heterogeneous catalyst was studied using a TGA instrument. This heterogeneous catalytic system showed a good performance in the coupling of aryl halides with alkynes (Sonogashira reaction) as well as aryl halides with alkene derivatives (Heck reaction). High to excellent yields were achieved for these C-C coupling reactions. The catalyst can be simply separated from the reaction media by an external magnet and reused for eight consecutive runs without any significant loss of activity. Finally, the kinetics of the reactions were studied in this work.
Sardarian, Ali Reza,Kazemnejadi, Milad,Esmaeilpour, Mohsen
p. 3132 - 3145
(2019/03/06)

Palladium-catalyzed Sonogashira coupling reactions in γ-valerolactone-based ionic liquids
It was demonstrated that the γ-valerolactone-based ionic liquid, tetrabutylphosphonium 4-ethoxyvalerate as a partially bio-based solvent can be utilized as alternative reaction medium for copper- and auxiliary base-free Pd-catalyzed Sonogashira coupling reactions of aryl iodides and functionalized acetylenes under mild conditions. Twenty-two cross-coupling products were isolated with good to excellent yields (72–99%) and purity (>98%). These results represent an example which proves that biomass-derived safer solvents can be utilized efficiently in common, industrially important transformations exhibiting higher chemical and environmental efficiency.
Orha, László,Tukacs, József M.,Kollár, László,Mika, László T.
supporting information
p. 2907 - 2913
(2019/12/14)

Visible Light-Catalyzed Decarboxylative Alkynylation of Arenediazonium Salts with Alkynyl Carboxylic Acids: Direct Access to Aryl Alkynes by Organic Photoredox Catalysis
A convenient method mediated by photoredox catalysis is developed for the direct construction of aryl alkynes. Readily available aromatic diazonium salts have been utilized as the aryl radical source to couple alkynyl carboxylic acids to feature the decarboxylative arylation. A wide range of substrates are amenable to this protocol with broad functional group tolerance, and diversely-functionalized aryl alkynes could be synthesized under mild, neutral and transition metal-free reaction conditions using visible light irradiation. Alongside synthetic sustainability associated with the photocatalytic and transition metal-free operation, another key point of this method is that the organic dye catalyst acts as an excited-state reductant, thus establishing the quenching cycle for radical addition and decarboxylative elimination. (Figure presented.).
Yang, Liangfeng,Li, Haifeng,Du, Yijun,Cheng, Kai,Qi, Chenze
p. 5030 - 5041
(2019/11/03)

Sequentially Pd/Cu-Catalyzed Alkynylation-Oxidation Synthesis of 1,2-Diketones and Consecutive One-Pot Generation of Quinoxalines
We report a simple and efficient one-pot synthesis of 1,2-diketones by concatenation of two Pd/Cu-catalyzed processes: Pd0/CuI-catalyzed Sonogashira coupling of terminal alkynes with aryl (pseudo)halides furnishes internal alkynes, which are directly transformed by PdII/CuII-catalyzed Wacker-type oxidation with DMSO and oxygen as dual oxidants to furnish 1,2-diketones. With this efficient, catalyst economical process, various aryl iodides and triflates are efficiently transformed in high yields into symmetrically and unsymmetrically substituted 1,2-diketones with various functional groups. This process can be readily extended to a consecutive one-pot synthesis of quinoxalines in a diversity-oriented fashion.
Niesobski, Patrik,Martínez, Ivette Santana,Kustosz, Sebastian,Müller, Thomas J. J.
supporting information
p. 5214 - 5218
(2019/07/31)

In Situ Generation of Alkynylzinc and Its Subsequent Negishi Reaction in a Flow Reactor
A highly efficient and convenient Negishi cross-coupling reaction has been developed for the synthesis of unsymmetrical alkynes and enynes in a continuous-flow process. The reaction proceeds through an in situ generated alkynylzinc reagent by the reaction of lithium acetylide with zinc halide at room temperature followed by a cross-coupling reaction with aryl or vinyl iodides. The notable features of this work compared to the conventional benchtop method are mild reaction conditions, good to excellent yields, broad functional-group compatibility, short residence time (73 sec) and especially desilylation of TMS group with the residence time of only 10.5 sec.
Kandasamy, Mohanraj,Huang, Yu- Hsuan,Ganesan, Balaji,Senadi, Gopal Chandru,Lin, Wei-Yu
p. 4349 - 4356
(2019/07/03)

Sonogashira Cross-Coupling of Aryltrimethylammonium Salts
A protocol for C(sp)-C(sp2) bond formation via the Sonogashira coupling reaction involving C-N bond cleavage with aryltrimethylammonium triflate as an electrophilic coupling partner is described in this work. The reactions proceeded well under mild conditions with a stoichiometric ratio of alkyl, aryl, or heteroaryl acetylenes and provided yields of up to 93%. Numerous useful functional groups were tolerated under the reaction conditions. Direct amine alkynylation can be achieved through a one-pot process without the isolation of ammonium salt. The protocol can be performed on a gram scale. Density functional theory calculations were performed to investigate the reaction mechanism that involved oxidative addition, alkyne coordination, deprotonation, and reductive elimination, which yielded the cross-coupling product.
Chen, Qianwei,Gao, Fengchen,Tang, Huiling,Yao, Miao,Zhao, Qian,Shi, Yanhui,Dang, Yanfeng,Cao, Changsheng
p. 3730 - 3736
(2019/04/13)

Pd-Catalyzed decarboxylative alkynylation of alkynyl carboxylic acids with arylsulfonyl hydrazides via a desulfinative process
In the presence of a Pd(ii)/P-ligand catalytic system, decarboxylative alkynylation of alkynyl carboxylic acids and arylsulfonyl hydrazides by desulfinative coupling could provide aryl alkynes in satisfactory yields by either judiciously selecting palladium catalysts or modulating phosphine ligands under mild conditions. The reported coupling reactions are very practical as they do not require the protection of inert gas or oxygen and are tolerant to many functional groups.
Chang, Sheng,Liu, Ying,Yin, Shu Zhu,Dong, Lin Lin,Wang, Jian Feng
supporting information
p. 5357 - 5362
(2019/04/04)

A novel zinc-catalyzed Suzuki-type cross-coupling reaction of aryl boronic acids with alkynyl bromides
A novel Suzuki-type cross-coupling reaction of organoboron reagents with alkynyl bromides has been developed in the presence of catalytic Et2Zn/DMEDA system. The reaction afforded a variety of internal alkynes in moderate to excellent yields under mild reaction conditions without the formation of any homo-coupling products. The resulting internal alkynes have valuable applications in pharmaceutical and industrial areas. The use of relatively non-toxic zinc, chelating amine ligand and low reaction temperature make this protocol an alternative for the synthesis of internal alkynes. The scope and limitations of this protocol are also investigated.
Keerthi Krishnan,Saranya, Salim,Rohit,Anilkumar, Gopinathan
p. 266 - 271
(2019/03/26)

Synthesis and characterization of γ-Fe2O3@SiO2-(CH2)3-PDTC-Pd magnetic nanoparticles: A new and highly active catalyst for the Heck/Sonogashira coupling reactions
In this research, the synthesis and characterization of a novel catalyst is reported based on the preparation of the Pd complex of (pyridin-2-ylmethyl)dithiocarbamate (PDTC) supported on γ-Fe2O3@SiO2 magnetic nanoparticles (γ-Fe2O3@SiO2-(CH2)3-PDTC-Pd). The catalyst is characterized by scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray spectroscopy, thermogravimetric analysis, Fourier transform infrared spectroscopy, inductively coupled plasma analysis, X-ray powder diffraction, X-ray photoelectron spectroscopy, and vibrating-sample magnetometer measurements. The catalytic performance of γ-Fe2O3@SiO2-(CH2)3-PDTC-Pd was evaluated in the Heck/Sonogashira coupling reactions of various aryl halides with various alkenes/phenylacetylene in water. The synthesized nanocatalyst showed a high catalytic activity even in very small amounts (5 mg, less than 0.1 mol%), was easily separated using magnetic decantation and was reused for ten cycles without any appreciable loss of its reactivity.
Tashrifi, Zahra,Bahadorikhalili, Saeed,Lijan, Hossein,Ansari, Samira,Hamedifar, Haleh,Mahdavi, Mohammad
p. 8930 - 8938
(2019/06/17)

Benzimidazolyl Palladium Complexes as Highly Active and General Bifunctional Catalysts in Sustainable Cross-Coupling Reactions
A family of air- A nd moisture-stable dinuclear palladium complexes bearing 2-benzimidazolyl ligands is reported and shown to be a highly effective and general catalytic platform in diverse cross-coupling reactions. The rigidity and conformation of the ligand scaffold was readily modified via tethering of the 2-benzimidazolyl moiety to diamine ligands, resulting in significant changes in catalytic activity. Under optimal conditions, Suzuki, Heck, and Sonogashira-type couplings of aryl bromides can all be performed efficiently with good functional group compatibility using only 0.1 mola?% of catalyst, in aqueous or alcohol solvents. Experimental evidence highlights the importance of the bifunctional character of the ligand for catalytic activity, where the basic N-functionality in the ligand framework is proposed to accelerate (trans)metalation steps via intramolecular assistance.
Zhu, Jiancheng,Lindsay, Vincent N. G.
p. 6993 - 6998
(2019/08/26)

Highly efficient synthesis of 1,2-disubstituted acetylenes derivatives from the cross-coupling reactions of 1-bromoalkynes with organoalane reagents
A Highly efficient route for the synthesis of 1,2-disubstituted acetylene derivatives has been developed by palladium catalyzed cross-couplings of alkynyl halides with (hetero)aryl aluminium reagents under mild conditions. This has given corresponding cross-coupling products good to excellent isolated yields of up to 99%. The aryls bearing electron-donating or electron-withdrawing groups in either alkynylhalides or arylaluminum substrates gave cross-coupling products good yields. This process was simple and easily performed, which provides an efficient method for the synthesis of 1,2-disubstituted acetylenes derivatives. On the basis of the experimental results, a possible catalytic cycle has been proposed.
Shao, Xue-Bei,Jiang, Xin,Li, Qing-Han,Zhao, Zhi-Gang
p. 6063 - 6070
(2018/09/12)

Recyclable heterogeneous metal foil-catalyzed cyclopropenation of alkynes and diazoacetates under solvent-free mechanochemical reaction conditions
Silver and copper foil were found to be effective, versatile and selective heterogeneous catalysts for the cyclopropenation of terminal and internal alkynes under mechanochemical reaction conditions. This methodology enables the functionalization of a wide range of terminal or internal alkynes under ambient, aerobic, and solvent-free conditions. Finally, we have demonstrated a unique and versatile one-pot domino Sonogashira-cyclopropenation mechanochemical reaction for the formation of complex cyclopropenes.
Chen, Longrui,Leslie, Devonna,Coleman, Michael G.,Mack, James
p. 4650 - 4661
(2018/05/30)