- Modification of the 4-phenylbutyl side chain of potent 3-benzazepine-based GluN2B receptor antagonists
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Excitotoxicity driven by overactivation of NMDA receptors represents a major mechanism of acute and chronic neurological and neurodegenerative disorders. Negative allosteric modulators interacting with the ifenprodil binding site of the NMDA receptor are able to interrupt this ongoing neurodamaging process. Starting from the potent 3-benzazepine-1,7-diol 4a novel NMDA receptor antagonists were designed by modification of the N-(4-phenylbutyl) side chain. With respect to developing novel fluorinated PET tracers, regioisomeric fluoroethoxy derivatives 11, 12, 14, and 15 were synthesized. Analogs 19 and 20 with various heteroaryl moieties at the end of the N-side chain were prepared by Sonogashira reaction and nucleophilic substitution. The fluoroethyl triazole 37 was obtained by 1,3-dipolar cycloaddition. In several new ligands, the flexibility of the (hetero)arylbutyl side chain was restricted by incorporation of a triple bond. The affinity towards the ifenprodil binding site was tested in an established competition assay using [3H]ifenprodil as radioligand. Introduction of a fluoroethoxy moiety at the terminal phenyl ring, replacement of the terminal phenyl ring by a heteroaryl ring and incorporation of a triple bond into the butyl spacer led to considerable reduction of GluN2B affinity. The phenol 15 (Ki = 193 nM) bearing a p-fluoroethoxy moiety at the terminal phenyl ring represents the most promising GluN2B ligand of this series of compounds. With exception of 15 showing moderate σ2 affinity (Ki = 79 nM), the interaction of synthesized 3-benzazepines towards the PCP binding site of the NMDA receptor, σ1 and σ2 receptors was rather low (Ki > 100 nM).
- Wagner, Marina,Schepmann, Dirk,Ametamey, Simon M.,Wünsch, Bernhard
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- Synthesis of palladated magnetic nanoparticle (Pd@Fe3O4/AMOCAA) as an efficient and heterogeneous catalyst for promoting Suzuki and Sonogashira cross-coupling reactions
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Palladium supported magnetic nanoparticle (Pd@Fe3O4/AMOCAA) was easily prepared in the presence of Scrophularia striata extract and fully characterized by FT-IR, SEM, VSM, TEM, TGA, XRD and EDAX. It was successfully employed as an easily separable and reusable effective heterogeneous catalyst classical Suzuki and Sonogashira cross-coupling reaction. Sustainability of the methodology was reserved by easy recovery of the catalyst using an external magnet and reusing it for 7 times without appreciable loss of its catalytic activity.
- Tamoradi, Taiebeh,Daraie, Mansoureh,Heravi, Majid M.
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- Mechanism of the copper-free palladium-catalyzed sonagashira reactions: Multiple role of amines
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Amines used as bases in copper-free, palladium-catalyzed Sonogashira reactions play a multiple role. The oxidative addition of iodobenzene with [Pd()(PPh3)4] is faster when performed in the presence of amines (piperidine>m
- Tougerti, Asma,Negri, Serge,Jutand, Anny
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- Tributylmanganate(II)-mediated cyclization of enynes
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Treatment of enynes with tributylmanganate(II) provided cyclized products containing alkylidene substituents. 1-Tridecen-6-yne or 1-tetradecen-7-yne gave 1-heptylidene-2-methylcyclopentane or 1-heptylidene-2-methylcyclohexane in 67 or 50% yield, respectiv
- Usugi,Shinokubo,Oshima
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- Gold-catalyzed tandem cycloisomerization-hydroalkoxylation of homopropargylic alcohols
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The tandem cycloisomerization-hydroalkoxylation of various homopropargylic alcohols in the presence of an alcohol and a dual catalyst system, consisting of a gold precatalyst and a Bronsted acid, provides an efficient route to tetrahydrofuranyl ethers und
- Belting, Volker,Krause, Norbert
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- A functionalized ionic liquid containing phosphine-ligated palladium complex for the Sonogashira reactions under aerobic and CuI-free conditions
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A Pd-complex functionalized ionic liquid (IL), di-(1-butyl-2- diphenylphosphino-3-methylimidazolium)-dichloropalladium(II) hexafluorophosphate (2), was synthesized and used as the highly efficient and recyclable catalyst for the Sonogashira reactions of aryl iodides and aryl bromides with several terminal acetylenes, under aerobic and CuI-free conditions. The activity loss, Pd black precipitation, and Pd leaching were not observed even after 7 runs in 2-catalyzed Sonogashira reactions using the room temperature IL of [Bmim]PF 6 as the reaction medium.
- Zhang, Jing,Crossed, Dakovi? Marijana,Popovi?, Zora,Wu, Haihong,Liu, Ye
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- New activators for the coupling reaction of terminal alkynes with organic halides
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Cross-coupling reactions of terminal alkynes with organic halides catalyzed by palladium(0) or palladium(0)/Cu(I) take place in the presence of several activators, such as silver(I) oxide, tetrabutylammonium fluoride (TBAF), and tetrabutylammonium hydroxi
- Ahmed, Mohamed S. Mohamed,Sekiguchi, Akitoshi,Shimada, Tomohiro,Kawashima, Jun,Mori, Atsunori
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- Thiol addition to aryl propargyl alcohols under mild conditions: An accelerating neighboring group effect
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Aryl alkynols provide a convenient entry into α-hydroxyketones via thiol addition followed by hydrolysis. Thiols have been added to several non- activated alkynes under mild, basic conditions. A coordinating functional group in close proximity to the triple bond facilitates this reaction.
- See Waters, Marjorie,Cowen, Jennifer A.,McWilliams, J. Christopher,Maligres, Peter E.,Askin, David
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- Reusable Cu2O/PPh3/TBAB system for the cross-couplings of aryl halides and heteroaryl halides with terminal alkynes
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(Chemical Equation Presented) An efficient and reusable Cu 2O/PPh3/TBAB (n-Bu4NBr) system for the cross-coupling reactions of aryl and heteroaryl halides with terminal alkynes has been developed. Four types of Cu2O, including bulky Cu 2O, cubic Cu2O nanoparticles, octahedral Cu2O nanoparticles, and spherical Cu2O nanoparticles, were examined, and the octahedral Cu2O nanoparticles were found to be the most effective catalyst for the reaction. In the presence of the octahedral Cu2O nanoparticles, PPh3, and TBAB, a variety of aryl and heteroaryl halides were reacted with alkynes including alkynols smoothly in moderate to good yields. Noteworthy is that the Cu2O/ PPh3/TBAB system can be recovered and reused several times without loss of any activities.
- Tang, Bo-Xiao,Wang, Feng,Li, Jin-Heng,Xie, Ye-Xiang,Zhang, Man-Bo
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- Amphiphilic ionic palladium complexes for aqueous-organic biphasic Sonogashira reactions under aerobic and CuI-free conditions
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The ionic Pd(II)-complexes of 2 (ammonium-[1-(2-hydroxyethyl)-3- methylimidazolium] bis[3-(diphenylphosphino)benzenesulfonate]- dichloropalladium(II) ([(NH4)(Hemim)][PdCl2(TPPMS) 2])) and 3 (bis[1-n-butyl-3-methylimidazolium] bis[3- (diphenylphosphino)benzenesulfonate]-dichloropalladium(II) ([Bmim] 2[PdCl2(TPPMS)2])) were synthesized and fully characterized. The single crystal X-ray diffraction analyses show that 2 and 3 are composed of the imidazolium-based cations and [PdCl2(TPPMS) 2]2 - anions. The properties of such imidazolium-based Pd-complexes of 2 and 3, in terms of the aqueous solubilities and the catalytic behaviors in water, could be dramatically varied. When 2 and 3 were applied as the precatalysts for the Sonogashira coupling of iodobenzene with phenylacetylene under aerobic and CuI-free conditions, the much higher yields of 1,2-diphenylethyne were obtained due to their amphiphilicity. The wide generality of 2 was available for aqueous-organic biphasic Sonogashira reactions.
- Wang, Xuezhu,Zhang, Jing,Wang, Yongyong,Liu, Ye
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- A Simple and Efficient Palladium Catalyst of Nitrogen-Based Ligand for Cu(I)- and Amine-Free Sonogashira Reaction
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Glycine, as a kind of commercially available and inexpensive ligand, is used to prepare an air-stable and water-soluble catalyst used in Sonogashira reaction in our study. In the presence of 1% [PdCl2(NH2CH2COOH)2/su
- Guo, Meng-Ping,Liu, Shi-Wen,Chen, San-Bao,Wen, Yong-Ju,Liang, Hui,Lv, Mei-Yun
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- On the catalytic duo PdCl2(PPh3)2/AuCl(PPh3) that cannot effect a Sonogashira-type reaction: a correction
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In contrast to the observation made by the Laguna group, we report that the combination of PdCl2(PPh3)2 and AuCl(PPh3) makes a unique catalytic system that allows Sonogashira-type cross-coupling of both aryl and alkyl alkynes with aryl halides in excellent yields.
- Panda, Biswajit,Sarkar, Tarun K.
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- SYNTHESIS OF α-ALKYLIDENE-γ-LACTONES BY INTRAMOLECULAR ADDITION OF ALKOXYCARBONYL FREE-RADICALS TO ACETYLENES
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α-Alkylidene-γ-lactones are obtained by treatment of chloroformate and selenocarbonate derivatives of homopropargylic alcohols with tri-n-butylstannane.
- Bachi, Mario D.,Bosch, Eric
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- Sonogashira reaction of aryl and heteroaryl halides with terminal alkynes catalyzed by a highly efficient and recyclable nanosized MCM-41 anchored palladium bipyridyl complex
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A heterogeneous catalyst, nanosized MCM-41-Pd, was used to catalyze the Sonogashira coupling of aryl and heteroaryl halides with terminal alkynes in the presence of CuI and triphenylphosphine. The coupling products were obtained in high yields using low Pd loadings to 0.01 mol%, and the nanosized MCM-41-Pd catalyst was recovered by centrifugation of the reaction solution and re-used in further runs without significant loss of reactivity.
- Lin, Bo-Nan,Huang, Shao-Hsien,Wu, Wei-Yi,Mou, Chung-Yuan,Tsai, Fu-Yu
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- Easy copper-, ligand- and amine-free sonogashira coupling reaction catalyzed by palladium on carbon at low catalyst loading and by exposure to air
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An easy copper-, ligand and amine-free Sonogashira coupling reaction catalyzed by commercially available palladium on carbon with air at low catalyst loading (0.2 mol% Pd) has been developed. Aryl iodides coupled with aromatic alkynes gave good to excelle
- Zhang, Guolin
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- Synthesis of alkenyl ylide complexes from reactions of ReOCl 2(OEt)(PPh3)2 with alkynols
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Reactions of both terminal and internal alkynols with ReOCl 2(OEt)(PPh3)2 (1) are described. Treatment of ReOCl2(OEt)(PPh3)2 (1) with HC≡CC 6H4-2-CH2OH and HC≡CCH2CH 2CH2OH produced the six-membered ylide complexes ReOCl2(C(=CH(PPh3))-C6H4-CH 2O)(PPh3) (2) and ReOCl2(C(=CH(PPh 3))CH2CH2CH2O)(PPh3) (3), respectvely, derived from addition of PPh3 to the terminal alkyne carbon. Similarly, phosphine addition to the terminal alkyne carbon occurred in the reactions of ReOCl2(OEt)(PPh3)2 (1) with HC≡CCH2CH(OH)Me and HC≡CCH2CH(OH)CH(OH)CH 2C≡CH to give the five-membered ylide complexes ReOCl 2(C(=CH(PPh3))CH2CH2CHMeO)(PPh 3) (5) and {ReOCl2(C(=CH(PPh3)CH 2CHO)(PPh3)}2 (6), respectively. Interestingly, related reactions of ReOCl2(OEt)(PPh3)2 with RC≡CCH2CH2OH (R = Me, Et, Ph) produced the six-membered ylide complexes ReOCl2(CR=C(PPh3)CH 2CH2O)(PPh3) (7, R = Me; 8, R = Et; 9, R = Ph), derived from addition of PPh3 to the alkyne carbon closer to the OH group.
- Poon, Ka Chun,Shi, Chuan,Sung, Herman H.-Y.,Williams, Ian D.,Lin, Zhenyang,Jia, Guochen
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- Polyoxometalate-Gold(I)/H+ Complexes: Air-Stable, Efficient, Polyvalent, and Bifunctional Catalysts
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Gold(I)/H+-polyoxometalate hybrids, with general formula [POM]x-[H]x-1+[R3PAu(MeCN)]+, were synthesized and fully characterized by 31P and 29Si MAS or liquid NMR, FT-I
- Hueber, Damien,Hoffmann, Marie,De Frémont, Pierre,Pale, Patrick,Blanc, Aurélien
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- Enantioselective Assembly of Cycloenones with a Nitrile-Containing All-Carbon Quaternary Center from Malononitriles Enabled by Ni Catalysis
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Chiral nitriles are valuable molecules in modern organic synthesis and drug discovery. Selectively differentiating the two nitrile groups of widely available malononitrile derivatives is a straightforward yet underdeveloped route to construct enantioenriched nitriles. Here we report an enantioselective nickel-catalyzed desymmetrization of malononitriles for the generation of nitrile-containing all-carbon quaternary stereocenters. This protocol involves a nickel-catalyzed addition of aryl boronic acids to alkynes, followed by a selective nitrile insertion, providing unprecedented access to enantioenriched 5-7-membered α-cyano-cycloenones with a fully substituted olefin from a broad range of substrates. The synthetic utility of these nitrile products is demonstrated by gram-scale synthesis and conversion to several useful functional groups.
- Lu, Zhiwu,Hu, Xu-Dong,Zhang, Hui,Zhang, Xiao-Wen,Cai, Jinhui,Usman, Muhammad,Cong, Hengjiang,Liu, Wen-Bo
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- An efficient palladium-catalysed reaction of vinyl and aryl halides or triflates with terminal alkynes
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In the presence of tetrakis(triphenylphosphine)palladium, vinyl and aryl halides or triflates react very rapidly in piperidine or pyrrolidine with terminal alkynes to give conjugated enynes and aryl acetylenes in high yields.
- Alami,Ferri,Linstrumelle
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- Construction of Condensed Polycyclic Aromatic Frameworks through Intramolecular Cycloaddition Reactions Involving Arynes Bearing an Internal Alkyne Moiety
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Facile synthetic methods for condensed polycyclic aromatic compounds via aryne intermediates are reported. The generation of arynes bearing a (3-arylpropargyl)oxy group from the corresponding o-iodoaryl triflate-type precursors efficiently afforded arene-fused oxaacenaphthene derivatives, which were formed through intramolecular [2+4] cycloaddition. Extending the method to the generation of arynes bearing a 1,3-diyne moiety led to a continuous generation of naphthalyne intermediate through the hexadehydro Diels–Alder reaction involving the aryne triple bond. This novel type of aryne-relay chemistry enabled the synthesis of a unique aminoarylated oxaacenaphthene derivative and highly ring-fused anthracene derivatives.
- Yoshida, Suguru,Shimizu, Keita,Uchida, Keisuke,Hazama, Yuki,Igawa, Kazunobu,Tomooka, Katsuhiko,Hosoya, Takamitsu
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- A phenyldithiocarbazate-functionalized polyvinyl chloride resinsupported Pd(II) complex as an effective catalyst for solvent- and copper-free Sonogashira reactions under aerobic conditions
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The PVC-supported phenyldithiocarbazate palladium complex was prepared and characterized. The catalyst exhibits excellent catalytic activity and stability for the Sonogashira coupling reaction under ambient conditions. Various terminal alkynes were coupled with a number of aryl halides in the presence of 1.0 mol% of the catalyst to afford the corresponding products in high yields. Furthermore, the heterogeneous catalyst can be readily recovered by simple filtration and reused for several times without a significant loss in its activity.2013 Elsevier B.V. All rights reserved.
- Bakherad, Mohammad,Keivanloo, Ali,Samangooei, Shahrzad,Omidian, Mina
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- Non-sonogashira-type palladium-catalyzed coupling reactions of terminal alkynes assisted by silver(I) oxide or tetrabutylammonium fluoride
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Palladium-catalyzed reaction of aryl and alkenyl halides with terminal alkynes in the presence of silver(I) oxide as an activator furnishes various arylated or alkenylated alkynes in good to excellent yields. The similar coupling reaction is also found to
- Mori, Atsunori,Kawashima, Jun,Shimada, Tomohiro,Suguro, Masahiro,Hirabayashi, Kazunori,Nishihara, Yasushi
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- Synthesis of Polysubstituted Fused Pyrroles by Gold-Catalyzed Cycloisomerization/1,2-Sulfonyl Migration of Yndiamides
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Yndiamides (bis-N-substituted alkynes) are valuable precursors to azacycles. Here we report a cycloisomerization/1,2-sulfonyl migration of alkynyl-yndiamides to form tetrahydropyrrolopyrroles, unprecedented heterocyclic scaffolds that are relevant to medicinal chemistry. This functional group tolerant transformation can be achieved using Au(I) catalysis that proceeds at ambient temperature, and a thermally promoted process. The utility of the products is demonstrated by a range of reactions to functionalize the fused pyrrole core.
- Smith, Philip J.,Jiang, Yubo,Tong, Zixuan,Pickford, Helena D.,Christensen, Kirsten E.,Nugent, Jeremy,Anderson, Edward A.
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supporting information
p. 6547 - 6552
(2021/08/30)
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- 3-Thiolated pyrroles/pyrrolines: controllable synthesis and usage for the construction of thiolated fluorophores
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Thiolation/cyclization of homopropargylic tosylamides allowed the selective synthesis of 3-thiolated pyrroles and pyrrolines controlled by solvents. Moreover, the desired 3-thiolated pyrroles were readily transformed to organic fluorophores benzothienopyrrole and bisthiolated boron dipyrromethene (S-BODIPY).
- Tian, Jun,Yuan, Kang-Ning,Liu, Wen,Chang, Hong-Hong,Li, Xing,Gao, Wen-Chao
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supporting information
p. 1943 - 1946
(2021/03/02)
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- Palladium-Catalyzed Synthesis of Tricyclic Indoles via a N-S Bond Cleavage Strategy
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In palladium/norbornene (Pd/NBE) chemistry, the "ortho effect"has been proven to be a key factor in the process of β-carbon elimination to extrude NBE. Herein, we found that the o-iodoaniline protected by a p-methoxybenzenesulfonyl group can recover the "
- Zhang, Bo-Sheng,Wang, Fan,Gou, Xue-Ya,Yang, Ying-Hui,Jia, Wan-Yuan,Liang, Yong-Min,Wang, Xi-Cun,Li, Yuke,Quan, Zheng-Jun
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supporting information
p. 7518 - 7523
(2021/10/01)
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- Directed Nickel-Catalyzed Diastereoselective Reductive Difunctionalization of Alkenyl Amines
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We report herein an intermolecular syn-arylalkylation and alkenylalkylation of alkenyl amines with two different organohalides (iodides and bromides) using Ni(II) catalyst. The cleavable bidentate quinolinamide is utilized after extensive directing group screening to enable olefin difunctionalization with high levels of regio-, chemo-, and diastereocontrol. This general and practical protocol is compatible with α- or β-substituted terminal alkenes and internal alkenes, providing rapid access to branched aliphatic amines bearing two skipped and vicinal stereocenters with high diastereoselectivities that would otherwise be difficult to synthesize.
- Zhao, Lei,Meng, Xiao,Zou, Yifeng,Zhao, Junsong,Wang, Lili,Zhang, Lanlan,Wang, Chao
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supporting information
p. 8516 - 8521
(2021/10/25)
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- Regioselective Formation of Substituted Indoles: Formal Synthesis of Lysergic Acid
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A Diels–Alder reaction-based strategy for the synthesis of indoles and related heterocycles is reported. An intramolecular cycloaddition of alkyne-tethered 3-aminopyrones gives 4-substituted indolines in good yield and with complete regioselectivity. Additional substitution is readily tolerated in the transformation, allowing synthesis of complex and non-canonical substitution patterns. Oxidative conditions give the corresponding indoles. The strategy also allows the synthesis of carbazoles. The method was showcased in a formal synthesis of lysergic acid.
- Beaudry, Christopher M.,Points, Gary L.,Stout, Kenneth T.
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supporting information
p. 16655 - 16658
(2020/12/01)
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- Distal Alkenyl C-H Functionalization via the Palladium/Norbornene Cooperative Catalysis
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A distal-selective alkenyl C-H arylation method is reported through a directed palladium/norbornene (Pd/NBE) cooperative catalysis. The key is to use an appropriate combination of the directing group and the NBE cocatalyst. A range of acyclic and cyclic c
- Dong, Guangbin,Fatuzzo, Nina,Wu, Zhao
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supporting information
p. 2715 - 2720
(2020/03/10)
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- Asymmetric Dearomatization of Indole by Palladium/PC-Phos-Catalyzed Dynamic Kinetic Transformation
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A palladium-catalyzed intermolecular dynamic kinetic asymmetric dearomatization of 3-arylindoles with internal alkynes was developed with the use of achiral Xantphos and chiral sulfinamide phosphine ligand (PC-Phos) as the co-ligands. This method could deliver various spiro[indene-1,3′-indole] compounds in good yields (up to 95 % yield) with up to 98 % ee. The salient features of the transformation include the use of readily available substrates, ease of scale-up and the versatile functionalization of the products. The mechanistic experiments gave some insights on active intermediates.
- Cheng, Jie,Chu, Haoke,Guo, Yin-Long,Yang, Junfeng,Zhang, Junliang
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supporting information
p. 21991 - 21996
(2020/10/02)
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- Preparation method of p-phenylbutoxybenzoic acid
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The invention provides a preparation method of p-phenylbutoxybenzoic acid. 3-alkynyl-1-butanol is used as a raw material, a catalyst is added, and p-phenylbutoxybenzoic acid is synthesized through four-step reaction. The preparation method comprises the f
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Paragraph 0050-0051
(2020/07/13)
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- External Oxidant-Free Oxidative Tandem Cyclization: NaI-Catalyzed Thiolation for the Synthesis of 3-Thiosubstituted Pyrroles
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A simple method for the synthesis of 3-thiosubstituted pyrroles from homopropargylic amines and thiosulfonates via a tandem sulfenylation/cyclization has been developed. The thiosulfonates are used both as substrates and oxidants in this transformation. This procedure exhibits good functional group tolerance and a series of 3-thiosubstituted pyrrole derivatives was obtained in moderate to good yields. (Figure presented.).
- Yuan, Bingxiang,Jiang, Yong,Qi, Zhenjie,Guan, Xin,Wang, Ting,Yan, Rulong
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supporting information
p. 5112 - 5117
(2019/11/11)
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- Synthesis of multi-substituted dihydrofurans via palladium-catalysed coupling between 2,3-alkadienols and pronucleophiles
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Multi-substituted dihydrofurans were obtained from a palladium-catalysed coupling reaction between 2,3-alkadienols and ketones bearing an electron-withdrawing group at the α-position. Methanol as a solvent was essential for the initial dehydrative substitution to suppress the competitive hydroalkylation of the diene moiety. The substitution would be followed by intramolecular hydroalkoxylation under the same catalysis.
- Tsukamoto, Hirokazu,Ito, Kazuya,Doi, Takayuki
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supporting information
p. 5102 - 5105
(2018/05/26)
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- Reductive Carbocyclization of Homoallylic Alcohols to syn-Cyclobutanes by a Boron-Catalyzed Dual Ring-Closing Pathway
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The organoborane-catalyzed reductive carbocyclization of homoallylic alcohols has been developed by using hydrosilanes as reducing reagents to provide a range of 1,2-disubstituted arylcyclobutanes. The reaction proceeds in a cis-selective manner with high efficiency under mild conditions. Mechanistic studies, including deuterium scrambling and Hammett studies, and DFT calculations, suggest a dual ring-closing pathway.
- Hazra, Chinmoy Kumar,Jeong, Jinhoon,Kim, Hyunjoong,Baik, Mu-Hyun,Park, Sehoon,Chang, Sukbok
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supporting information
p. 2692 - 2696
(2018/02/09)
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- Tert-Butyl Nitrite Promoted Oxidative Intermolecular Sulfonamination of Alkynes to Synthesize Substituted Sulfonyl Pyrroles from the Alkynylamines and Sulfinic Acids
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tert-Butyl nitrite promoted oxidative intermolecular sulfonamination of alkynes to synthesize substituted sulfonyl pyrroles from the alkynylamines and sulfinic acids via tandem addition/cyclization was developed. This reaction is performed well by employing tert-butyl nitrite as the oxidant, and various substituted sulfonyl pyrroles are formed in moderate to good yields with no requirement of metal catalysis.
- Qi, Zhenjie,Jiang, Yong,Wang, Yanyan,Yan, Rulong
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supporting information
p. 8636 - 8644
(2018/06/18)
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- Cu-Catalyzed Tandem Aerobic Oxidative Cyclization for the Synthesis of 3,3′-Bipyrroles from the Homopropargylic Amines
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A Cu-catalyzed method for the synthesis of 3,3′-bipyrroles from homopropargylic amines through tandem aerobic oxidative cyclization involving the formation of C-C bond has been developed. The features of this reaction are a small number of Cu catalysis and simple starting substrates. Moreover, this procedure exhibits good functional group tolerance and a series of 3,3′-bipyrroles derivatives are obtained in moderate to good yields.
- Qi, Zhenjie,Jiang, Yong,Yuan, Bingxiang,Niu, Yanning,Yan, Rulong
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supporting information
p. 5048 - 5052
(2018/08/24)
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- Asymmetric Synthesis of Fused Bicyclic N,O- and O,O-Acetals via Cascade Reaction by Gold(I)/N,N′-Dioxide-Nickel(II) Bimetallic Relay Catalysis
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An efficient catalytic asymmetric cyclization/inverse-electron-demand hetero-Diels-Alder cascade reaction of β,γ-unsaturated α-ketoesters with alkyl amides or alcohols were accomplished. The process was based on the utilization bimetallic catalyst system with achiral gold(I) catalyst and chiral N,N′-dioxide/Ni(II) catalyst, delivering a variety of fused bicyclic N,O-acetals or O,O-acetals in up to 99% yield and 99% ee with >19:1 dr under mild reaction conditions. Based on the control experiments and previous studies, a possible reaction pathway of bimetallic relay catalysis cascade reactions was presented. (Figure presented.).
- Hu, Bowen,Li, Jun,Cao, Weidi,Lin, Qianchi,Yang, Jian,Lin, Lili,Liu, Xiaohua,Feng, Xiaoming
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supporting information
p. 2831 - 2835
(2018/08/17)
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- Method for synthesizing substituted furan
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Provided is a method for synthesizing substituted furan. Iodohydrocarbon and terminal propargyl alcohol produce Sonogashira coupling reaction to generate an intermediate product 3-alkyne-1-alcohol, then isomeric cyclization occurs under the effect of Dess
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Paragraph 0010
(2017/12/09)
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- DNA-supported palladium nanoparticles as a reusable catalyst for the copper- and ligand-free Sonogashira reaction
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DNA nanotechnology has recently emerged as a powerful discipline with diverse applications. However, studies focused on the combination of DNA and metal nanoparticles for catalyst design are scanty. We have prepared a catalyst composed of palladium nanoparticles supported on DNA which has been characterised by TEM, SEM, EDX, UV, FTIR and XPS. The catalyst, mainly composed of Pd(ii) and Pd(iv) species in the form of oxides, has been effectual in the copper- and ligand-free Sonogashira-Hagihara coupling of aryl iodides with terminal aromatic and aliphatic alkynes. The products are obtained in 54-86% isolated yields using low catalyst loading (0.5 mol%) under mild conditions (65 °C) in methanol without air exclusion. Moreover, the catalyst can be easily recovered and reused in five cycles and shows better performance than an array of commercial palladium catalysts. The mechanistic aspects of the reaction are also tackled in detail.
- Camacho, Ana Silvia,Martín-García, Iris,Contreras-Celedón, Claudia,Chacón-García, Luis,Alonso, Francisco
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p. 2262 - 2273
(2017/07/24)
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- Accessing alternative reaction pathways of the intermolecular condensation between homo-propargyl alcohols and terminal alkynes through divergent gold catalysis
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An intermolecular condensation of alkynols and terminal alkynes is reported. Using IPrAuNTf2, an efficient Au-catalyzed cyclization-alkynylation strategy furnishes (2-arylalkynyl) cyclic ethers in moderate to excellent yields (up to 94%). This strategy is extended to the synthesis of functionalized 2,3-dihydrooxepines via the sequential Au-catalyzed ring expansion of the cyclic ether substrates.
- Smith, Courtney A.,Motika, Stephen E.,Wojtas, Lukasz,Shi, Xiaodong
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supporting information
p. 2315 - 2318
(2017/02/23)
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- A method for accessing sulfanylfurans from homopropargylic alcohols and sulfonyl hydrazides
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A sulfenylation/cyclization reaction has been developed for the synthesis of sulfanylfurans in the presence of iodine. These processes provide facile strategies to construct C-S/O bonds, and expand the methods of synthesizing sulfanylfurans. In this trans
- Yan, Rulong,Yang, Xiaodong
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supporting information
p. 3571 - 3574
(2019/06/13)
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- Regioselective Amine–Borane Cyclization: Towards the Synthesis of 1,2-BN-3-Cyclohexene by Copper-Assisted Triazole/Gold Catalysis
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The combination of triazole/gold (TA-Au) and Cu(OTf)2is identified as the optimal catalytic system for promoting intramolecular hydroboration for the synthesis of a six-membered cyclic amine–borane. Excellent yields (up to 95 %) and regioselectivities (5-exo vs. 6-endo) were achieved through catalyst control and sequential dilution. Good functional-group tolerance was attained, thus allowing the preparation of highly functionalized cyclic amine–borane substrates, which could not be achieved using other methods. Deuterium-labeling studies support the involvement of a hydride addition to a gold-activated alkyne with subsequent C?B bond formation.
- Motika, Stephen E.,Wang, Qiaoyi,Akhmedov, Novruz G.,Wojtas, Lukasz,Shi, Xiaodong
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supporting information
p. 11582 - 11586
(2016/10/24)
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- Synthesis of functionalized alkynes via palladium-catalyzed Sonogashira reactions
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A highly efficient protocol for the copper and phosphine free Sonogashira cross-coupling reactions of aryl iodides with terminal alkynes under aerobic conditions has been developed. Using 1 mol % of the palladium-bis(oxazoline) complex, Pd-BOX A, in the p
- Ibrahim, Mansur B.,Ali, Bassam El,Malik, Imran,Fettouhi, Mohammed
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p. 554 - 558
(2016/01/20)
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- Cu-catalyzed intramolecular aryl-etherification reactions of alkoxyl alkynes with diaryliodonium salts via cleavage of a stable C-O bond
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A novel Cu-catalyzed intramolecular aryl-etherification reaction of alkoxyl alkynes with diaryliodonium salts is realized. The reactions proceed smoothly to produce valuable oxo-heterocycles with readily available linear starting materials via cleavage of a stable C-O bond. This journal is
- Chen, Jing,Chen, Chao,Chen, Junjie,Wang, Guohua,Qu, Hongmei
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supporting information
p. 1356 - 1359
(2015/02/05)
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- Regioselective iodoazidation of alkynes: Synthesis of α,α-diazidoketones
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Aryl alkyl alkynes reacted with N-iodosuccinimide (NIS) and trimethylsilyl azide (TMSN3), leading to α,α-diazidoketones via the regioselective addition of IN3 to alkynes. Huisgen cyclization of α,α-diazidoketones generated bis-triazo
- Okamoto, Noriko,Sueda, Takuya,Minami, Hideki,Miwa, Yoshihisa,Yanada, Reiko
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supporting information
p. 1336 - 1339
(2015/03/14)
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- Rhodium(III)-catalyzed oxidative bicyclization of 4-arylbut-3-yn-1-amines with internal alkynes through C-H functionalization
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A new Rh(III)-catalyzed oxidative bicyclization through C-H functionalization is presented. This reaction allows the selective assembly of diverse benzo[g]indoles from 4-arylbut-3-yn-1-amines and internal alkynes via a sequence of aromatic C(sp2)-H functionalization, cyclodimerization and nucleophilic cyclization.
- Pi, Rui,Zhou, Ming-Bo,Yang, Yuan,Gao, Cai,Song, Ren-Jie,Li, Jin-Heng
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supporting information
p. 13550 - 13553
(2015/09/01)
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- Highly enantioselective nickel-catalyzed intramolecular reductive cyclization of alkynones
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The first asymmetric nickel-catalyzed intramolecular reductive cyclization of alkynones is reported. A P-chiral monophosphine and triethylsilane were used as the ligand and the reducing reagent, respectively, to form a series of tertiary allylic alcohols bearing furan/pyran rings in excellent yields and enantioselectivities. This reaction has a broad substrate scope and enabled the efficient synthesis of dehydroxycubebin and chiral dibenzocyclooctadiene skeletons.
- Fu, Wenzhen,Nie, Ming,Wang, Aizhen,Cao, Ziping,Tang, Wenjun
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supporting information
p. 2520 - 2524
(2015/03/04)
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- Cu-catalyzed arylcarbocyclization of alkynes with diaryliodonium salts through C-c bond formation on inert C(sp3)-H bond
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Copper-catalyzed arylcarbocyclization reaction of alkynes was realized with diaryliodonium salts through C-C bond formation on an inert C(sp3)-H bond. This method provides an efficient cyclization of alkyl alkynes to generate carbocycles with good step-economy. Theoretical study revealed an interesting Cu-catalyzed concerted pathway of the C-C bond formation.
- Peng, Jing,Chen, Chao,Chen, Junjie,Su, Xiang,Xi, Chanjuan,Chen, Hui
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supporting information
p. 3776 - 3779
(2014/08/05)
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- The mechanism of gold(I)-catalyzed hydroalkoxylation of alkynes: An extensive experimental study
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An extensive experimental study of the mechanism of gold(I)-catalyzed hydroalkoxylation of internal alkynes has been conducted by using NMR spectroscopy. This study was focused on the organogold intermediates, observations of actual catalytic intermediates in situ, and the reaction kinetics that are involved in this reaction. Based on the experimental results, a complete mechanistic picture was established, including on- and off-cycle processes that explain the role of diaurated species. We have shown that gold-catalyzed hydroalkoxylation of internal alkynes is a reaction that requires only one gold atom for the catalytic cycle, disproving a recent hypothesis regarding the involvement of cooperative gold catalysis.
- Zhdanko, Alexander,Maier, Martin E.
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supporting information
p. 1918 - 1930
(2014/03/21)
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- Rh(III)-catalyzed intramolecular redox-neutral or oxidative cyclization of alkynes: Short, efficient synthesis of 3,4-fused indole skeletons
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A Rh(III)-catalyzed intramolecular redox-neutral or oxidative annulation of a tethered alkyne has been developed to efficiently construct 3,4-fused indoles via a C-H activation pathway. The advantages of this process are (1) ready availability of annulation precursors; (2) broad substrate scope; (3) complete regioselectivity; (4) simple and mild reaction conditions; and (5) no need for an external oxidant or to employ molecular oxygen as the stoichiometric terminal oxidant.
- Zhou, Bing,Yang, Yaxi,Tang, Huanyu,Du, Juanjuan,Feng, Huijin,Li, Yuanchao
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supporting information
p. 3900 - 3903
(2014/08/18)
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- Palladium nanoparticles in glycerol: A versatile catalytic system for C-X bond formation and hydrogenation processes
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Palladium nanoparticles stabilised by tris(3-sulfophenyl)phosphine trisodium salt in neat glycerol have been synthesised and fully characterised, starting from both Pd(II) and Pd(0) species. The versatility of this innovative catalytic colloidal solution has been proved by its efficient application in C-X bond formation processes (X=C, N, P, S) and C-C multiple bond hydrogenation reactions. The catalytic glycerol phase could be recycled more than ten times, preserving its activity and selectivity. The scope of each of these processes has demonstrated the power of the as-prepared catalyst, isolating the corresponding expected products in yields higher than 90%. The dual catalytic behaviour of this glycerol phase, associated to the metallic nanocatalysts used in wet medium (molecular- and surface-like behaviour), has allowed attractive applications in one-pot multi-step transformations catalysed by palladium, such as C-C coupling followed by hydrogenation, without isolation of intermediates using only one catalytic precursor. Copyright
- Chahdoura, Faouzi,Pradel, Christian,Gomez, Montserrat
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supporting information
p. 3648 - 3660
(2014/01/06)
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- Silver-catalysed intramolecular hydroamination of alkynes with trichloroacetimidates
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Silver(i) complexes catalyse the intramolecular addition of trichloroacetimidates to alkynes. In the absence of a ligand, the selectivity of the reaction is dependent upon the nature of the counter-anion and solvent. The introduction of non-chelating nitrogeneous ligands suppresses competitive Bronsted acid catalysis, improving the yield and selectivity of the reaction.
- Wong, Valerie H. L.,Hor, T. S. Andy,Hii, King Kuok
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supporting information
p. 9272 - 9274
(2013/10/01)
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- Gold and palladium combined for the Sonogashira coupling of aryl and heteroaryl halides
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A highly efficient gold and palladium combined methodology for the Sonogashira coupling of a wide array of electronically and structurally diverse aryl and heteroaryl halides is described. The orthogonal reactivity of the two metals shows high selectivity and extreme functional group tolerance in Sonogashira coupling. A brief mechanistic study reveals that the gold acetylide intermediate enters into the palladium catalytic cycle at the transmetalation step. Georg Thieme Verlag Stuttgart.New York.
- Panda, Biswajit,Sarkar, Tarunk.
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p. 817 - 829
(2013/04/10)
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- Asymmetric 5-endo chloroetherification of homoallylic alcohols toward the synthesis of chiral β-chlorotetrahydrofurans
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An asymmetric 5-endo chloroetherification of homoallylic alcohols is successfully developed that employs an easily available quaternary ammonium salt derived from cinchonine as a conventional organocatalyst. This approach provides ready access to β-chloro
- Zeng, Xianghua,Miao, Chengxia,Wang, Shoufeng,Xia, Chungu,Sun, Wei
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supporting information
p. 2418 - 2420
(2013/04/10)
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- The combination of relay and cooperative catalysis with a gold/palladium/brnsted acid ternary system for the cascade hydroamination/ allylic alkylation reaction
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The combination of relay and cooperative catalysis with a gold/palladium/Brnsted acid ternary system renders a cascade hydroamination/allylic alkylation reaction to provide an unprecedented entry to pyrrolidine derivatives in high yields. Copyright
- Wu, Hua,He, Yu-Ping,Gong, Liu-Zhu
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supporting information; experimental part
p. 975 - 980
(2012/05/20)
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- Rhodium(III)-catalyzed intramolecular annulation through C-H activation: Total synthesis of (±)-antofine, (±)-septicine, (±)-tylophorine, and rosettacin
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Annulation: The efficient synthesis of 3-hydroxyalkyl isoquinolones and 6-hydroxyalkyl 2-pyridones is enabled through the intramolecular annulation of alkyne-tethered hydroxamic esters (see scheme, Cp= pentamethylcyclopentadienyl). The reaction features high regioselectivity, broad substrate scope, and excellent functional-group tolerance, proceeds under mild reaction conditions with low catalyst loading, and obviates the need for an external oxidant.
- Xu, Xianxiu,Liu, Yu,Park, Cheol-Min
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supporting information
p. 9372 - 9376
(2012/10/29)
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- Synthesis of propargylic and allenic carbamates via the C-H amination of alkynes
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Propargylic amines are important intermediates for the synthesis of nitrogen-containing heterocycles. The insertion of a nitrene into a propargylic C-H bond has not been explored, despite the attention directed toward the Rh-catalyzed amination of other t
- Grigg, R. David,Rigoli, Jared W.,Pearce, Simon D.,Schomaker, Jennifer M.
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supporting information; experimental part
p. 280 - 283
(2012/02/16)
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- Cascading radical cyclization of bis-vinyl ethers: Mechanistic investigation reveals a 5-exo/3-exo /retro-3-exo/5-exo pathway
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We recently described an iterative synthesis of oligo-vinyl ethers, followed by a radical cascade to provide a family of hexahydro-2H-furo[3,4-b] pyrans. Our results for the radical cascade were consistent with either a direct 6-endo-trig addition of a vinyl radical onto the first vinyl ether function or an initial 5-exo-trig addition, followed by rearrangement to the more stable anomeric radical intermediate. In this report, we describe our further mechanistic studies aimed at distinguishing between these two possibilities and conclude that the 5-exo/3-exo/retro-3-exo pathway is dominant.
- O'Rourke, Natasha F.,Davies, Katherine A.,Wulff, Jeremy E.
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p. 8634 - 8647,14
(2020/09/15)
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- Addition of arylboronic acids to arylpropargyl alcohols en route to indenes and quinolines
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A regio- and stereoselective rhodium-catalyzed synthesis of trisubstituted allylic alcohols is described. The utility of these synthons is demonstrated in a convenient synthesis of indenes and quinolines.
- Panteleev, Jane,Huang, Richard Y.,Lui, Erica K. J.,Lautens, Mark
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supporting information; experimental part
p. 5314 - 5317
(2011/12/01)
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- One-pot synthesis of benzo[f]quinolin-3-ones and benzo[a]phenanthridein-5- ones by the photoanuulation of 6-chloropyridin-2-ones and 3-chloroisoquinolin-1- ones to phenylacetylene
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The one-pot synthesis of benzo[f]quinolin-3-ones and benzo[a] phenanthridein-5-ones was achieved by the inter- and intramolecular photoannulation of 6-chloropyridin-2-ones and 3-chloroisoquinolin-1-ones with phenylacetylene or tethered phenylacetylene. The reactions were proceeded by photoaddition of 6-chloropyridin-2-ones and 3-chloroisoquinolin-1-ones to phenylacetylene to give the chlorine-substituted stilbenoids, and then 6π electrocyclization of the stilbenoids and oxidation aromatization to afford the polycyclic products.
- Wang, Ren,Lu, Shen-Ci,Zhang, Yi-Ming,Shi, Zong-Jun,Zhang, Wei
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supporting information; experimental part
p. 5802 - 5808
(2011/10/02)
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- Palladium-catalysed cyclisation of N-alkynyl aminomalonates
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Go around in (hetero)cycles! The palladium-catalysed tandem cyclisation/coupling reaction of alkynyl- and alkenyl-substituted aminomalonates leads to highly functionalised pyrrolidines and piperidines in good yield (see scheme). The reaction allows efficient access to a broad range of synthetically valuable building blocks.
- Hess, Wilfried,Burton, Jonathan W.
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supporting information; experimental part
p. 12303 - 12306
(2011/02/23)
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- A convergent general strategy for the functionalized 2-Aryl cycloalkylfused chromans: Intramolecular hetero-diels-alder reactions of ortho-quinone methides
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(Figure Presented) Five and six: 3, 4-Cyclopentyl- and cyclohexyl-fused 2-arylchromans could be readily prepared from the intramolecular hetero-Diels-Alder reactions of the corresponding ortho-quinone methide (o-QM) precursors tethered to the styrenes under mild reaction conditions. The products were obtained with good to excellent diastereoselectivity (up to > 99:1 dr; see scheme; MOM = methoxymethyl).
- Tummatorn, Jumreang,Ruchirawat, Somsak,Ploypradith, Poonsakdi
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supporting information; experimental part
p. 1445 - 1448
(2010/06/17)
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