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Search for "H-bond activation" in Full Text gives 63 result(s) in Beilstein Journal of Organic Chemistry.

Architecture and synthesis of P,N-heterocyclic phosphine ligands

  • Wisdom A. Munzeiwa,
  • Bernard Omondi and
  • Vincent O. Nyamori

Beilstein J. Org. Chem. 2020, 16, 362–383, doi:10.3762/bjoc.16.35

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  • from α-C–H bond activation in heterocycles The α-position to a heteroatom in a cyclic compound is activated because of the difference in electronegativity with carbon. This presents an opportunity to readily generate organometallic nucleophiles. Chelucci et al. [71] used this fact to synthesize the
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Published 12 Mar 2020

Recent advances in transition-metal-catalyzed incorporation of fluorine-containing groups

  • Xiaowei Li,
  • Xiaolin Shi,
  • Xiangqian Li and
  • Dayong Shi

Beilstein J. Org. Chem. 2019, 15, 2213–2270, doi:10.3762/bjoc.15.218

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  • intermediate B through the C–H bond-activation process. Oxidative addition of the intermediate B with Selectfluor affords the palladium(IV) species C, followed by reductive elimination and ligand dissociation to give the final product. Similar to these publications in strategy and products, in the same year
  • process, an in situ-generated cationic [Pd(NO3)]+ species facilitates the C–H bond activation to give intermediate A. The Pd(II)(1a)2 complex B is formed via further C–H bond activation of another molecule 1a by the cyclopalladation(II) intermediate A. Then, intermediate B undergoes oxidative addition by
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Published 23 Sep 2019

Regioselective Pd-catalyzed direct C1- and C2-arylations of lilolidine for the access to 5,6-dihydropyrrolo[3,2,1-ij]quinoline derivatives

  • Hai-Yun Huang,
  • Haoran Li,
  • Thierry Roisnel,
  • Jean-François Soulé and
  • Henri Doucet

Beilstein J. Org. Chem. 2019, 15, 2069–2075, doi:10.3762/bjoc.15.204

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  • methodology provides a straightforward access to several lilolidine derivatives from commercially available compounds via one, two or three C–H bond functionalization steps allowing to tune their biological properties. Keywords: catalysis: C–C bond formation; C–H bond activation; lilolidine; palladium
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Published 29 Aug 2019

Attempted synthesis of a meta-metalated calix[4]arene

  • Christopher D. Jurisch and
  • Gareth E. Arnott

Beilstein J. Org. Chem. 2019, 15, 1996–2002, doi:10.3762/bjoc.15.195

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  • ) and rhodium(III) complexes underwent spontaneous, chemoselective cyclometalation via C–H bond activation of the N-bound phenyl group (see Figure 2) [19]. Incorporation of a mesoionic carbene directing group onto the upper rim of a calix[4]arene therefore offered potential for a new route to calix[4
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Published 22 Aug 2019

Recent advances on the transition-metal-catalyzed synthesis of imidazopyridines: an updated coverage

  • Gagandeep Kour Reen,
  • Ashok Kumar and
  • Pratibha Sharma

Beilstein J. Org. Chem. 2019, 15, 1612–1704, doi:10.3762/bjoc.15.165

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  • high level of functional group compatibility, intramolecular alkylations, inter and intramolecular C–H bond activation and regio/stereoselective homocoupling of alkynes [71][72][73]. Group of Cho and Chang have unprecedentedly reported a Rh catalytic system for facile addition of heteroarenes to both
  • ). However, the reaction was unsuccessful with aliphatic and low-boiling aldehydes (as the reaction was taking place at high temperature). The reaction mechanism involved a Cu-NPs-mediated C–H bond activation of the alkyne which further reacted with the iminium ion to form propargylamine 45 and Cu NPs were
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Published 19 Jul 2019

Mechanochemistry of supramolecules

  • Anima Bose and
  • Prasenjit Mal

Beilstein J. Org. Chem. 2019, 15, 881–900, doi:10.3762/bjoc.15.86

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  • , Figure 4b). Contrastingly, in solution the same synthesis took 4 h at 70 °C to isolate complex 9 in 56% yield. Ćurić and co-workers prepared cyclopalladated complexes such as 10 by a grinding method and were the first to confirm a mechanochemical C–H bond activation of an unsymmetrically substituted
  • salen-type ligand followed by metal-complex formation in the same pot [55]. Otera’s solvent-free approach by which the formation of self-assembled supramolecules could be accelerated [56]. Synthesis of a Pd-based metalla-supramolecular assembly through mechanochemical activation for C–H-bond activation
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Published 12 Apr 2019

Cobalt- and rhodium-catalyzed carboxylation using carbon dioxide as the C1 source

  • Tetsuaki Fujihara and
  • Yasushi Tsuji

Beilstein J. Org. Chem. 2018, 14, 2435–2460, doi:10.3762/bjoc.14.221

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  • Rh complex B (step a). Then, chelation-assisted C–H bond activation proceeds to generate a rhodacycle C (step b). The reaction of C with CO2 affords an eight-membered rhodacycle intermediate D (step c). Next, D is converted to the corresponding rhodium complex E by ligand exchange with KOAc (step d
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Published 19 Sep 2018

Selective carboxylation of reactive benzylic C–H bonds by a hypervalent iodine(III)/inorganic bromide oxidation system

  • Toshifumi Dohi,
  • Shohei Ueda,
  • Kosuke Iwasaki,
  • Yusuke Tsunoda,
  • Koji Morimoto and
  • Yasuyuki Kita

Beilstein J. Org. Chem. 2018, 14, 1087–1094, doi:10.3762/bjoc.14.94

Graphical Abstract
  • oxidation forming aryl ketones [52]. Note that the successful coupling of a range of secondary and tertiary carboxylic acids now supports the direct and selective C–H bond activation at the benzyl position by avoiding the formation of carbonyloxy radicals, which are susceptible to decarboxylation. In
  • known to readily abstract hydrogen atoms at the tertiary carbon centers [79], the results suggest a predominant participation of the iodanyl radical as the hydrogen atom abstractor for the selective secondary benzylic C–H bond activation in our reaction. It seems that the iodanyl radical is more
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Published 16 May 2018

Palladium-catalyzed ortho-halogenations of acetanilides with N-halosuccinimides via direct sp2 C–H bond activation in ball mills

  • Zi Liu,
  • Hui Xu and
  • Guan-Wu Wang

Beilstein J. Org. Chem. 2018, 14, 430–435, doi:10.3762/bjoc.14.31

Graphical Abstract
  • ][24][25][26][27][28]. A few mechanochemical ortho-C–H bond activation reactions under the catalysis of rhodium and palladium salts have been reported [29][30][31][32][33][34][35][36][37][38]. Hernández and Bolm reported the rhodium-catalyzed bromination and iodination of 2-phenylpyridine using N
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Published 16 Feb 2018

Progress in copper-catalyzed trifluoromethylation

  • Guan-bao Li,
  • Chao Zhang,
  • Chun Song and
  • Yu-dao Ma

Beilstein J. Org. Chem. 2018, 14, 155–181, doi:10.3762/bjoc.14.11

Graphical Abstract
  • allylic CF3 bonds from olefins. Following examples described the straightforward trifluoromethylation of terminal alkenes via allylic C(sp3)–H bond activation generating allylic trifluoromethylated compounds. In 2011, the group of Fu and Liu [49] described an unprecedented type of a Cu-catalyzed
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Published 17 Jan 2018

Reactivity of bromoselenophenes in palladium-catalyzed direct arylations

  • Aymen Skhiri,
  • Ridha Ben Salem,
  • Jean-François Soulé and
  • Henri Doucet

Beilstein J. Org. Chem. 2017, 13, 2862–2868, doi:10.3762/bjoc.13.278

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  • synthesis of unsymmetrical 2,5-di(hetero)arylated selenophene derivatives in three steps from selenophene. Keywords: C–H bond activation; catalysis; heteroarenes; palladium; selenophene; Introduction (Hetero)aryl-substituted selenophenes represent a class of molecules which exhibit useful physical
  • recent years, the Pd-catalyzed arylation, via a C–H bond activation, of a broad range of heteroaromatics using aryl halides as reaction partners was demonstrated to be particularly effective for the preparation of bi(hetero)aryls [22][23][24][25][26][27][28][29][30][31]. Among the reported results, a few
  • examples of Pd-catalyzed direct arylations via the C–H bond activation of selenophenes using aryl halides as coupling partners have been reported [32][33][34][35]. Conversely, C–H bond activation methodology was employed in only in one case for the preparation of a heteroarylated selenophene from a
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Published 22 Dec 2017

Transition-metal-free synthesis of 3-sulfenylated chromones via KIO3-catalyzed radical C(sp2)–H sulfenylation

  • Yanhui Guo,
  • Shanshan Zhong,
  • Li Wei and
  • Jie-Ping Wan

Beilstein J. Org. Chem. 2017, 13, 2017–2022, doi:10.3762/bjoc.13.199

Graphical Abstract
  • . Presently, the most popular approaches in constructing a C(sp2)–S bond are the transition-metal-catalyzed Ullmann C–S coupling reaction [4][5][6][7][8], Chan–Lam cross-coupling reaction [9][10][11][12] as well as the transition-metal-catalyzed C–H bond activation [13][14][15]. Recently, as a new trend, the
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Published 27 Sep 2017

Mechanochemical synthesis of small organic molecules

  • Tapas Kumar Achar,
  • Anima Bose and
  • Prasenjit Mal

Beilstein J. Org. Chem. 2017, 13, 1907–1931, doi:10.3762/bjoc.13.186

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  • Aleksanyan and co-workers reported the first gram-scale synthesis of a PdII organometallic pincer complex under mechanomilling via C–H bond activation. After successful isolation of the PdII pincer complex by grinding of bis(thiocarbamate) and PdCl2(NCPh)2 they could scale up the reaction up to 1.76 mmol
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Published 11 Sep 2017

Synthesis of alkynyl-substituted camphor derivatives and their use in the preparation of paclitaxel-related compounds

  • M. Fernanda N. N. Carvalho,
  • Rudolf Herrmann and
  • Gabriele Wagner

Beilstein J. Org. Chem. 2017, 13, 1230–1238, doi:10.3762/bjoc.13.122

Graphical Abstract
  • all atoms of the starting material are found in the product, and thus fulfil an important requirement of “green chemistry” [31]. However, a different Pt(II)-catalysed reaction cascade was observed for 4c, with adamantyl groups at the alkynes. Here, the annulation step is followed by a C–H bond
  • -activation process, to establish an additional bond to one of the adamantyl groups (8 in Scheme 3b) [32]. The simplest diyne 4d with R = H, in contrast, gave a ring enlargement from six to seven members together with a 1,2-oxygen shift instead (9 in Scheme 3c) [33]. This clearly demonstrates that the
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Published 26 Jun 2017

The reductive decyanation reaction: an overview and recent developments

  • Jean-Marc R. Mattalia

Beilstein J. Org. Chem. 2017, 13, 267–284, doi:10.3762/bjoc.13.30

Graphical Abstract
  • removal of a beneficial functional group. The electron-withdrawing properties of the nitrile functional group appear beneficial in a variety of reactions [1][2]. This group coordinates metal complexes and can be used as a directing group for C–H bond activation reactions catalyzed by transition metals [3
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Published 13 Feb 2017

Direct arylation catalysis with chloro[8-(dimesitylboryl)quinoline-κN]copper(I)

  • Sem Raj Tamang and
  • James D. Hoefelmeyer

Beilstein J. Org. Chem. 2016, 12, 2757–2762, doi:10.3762/bjoc.12.272

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  • addition/reductive elimination. The scope of reactivity, including functional group tolerance on the reactants, types of C–H bonds that can be activated, selectivity of C–H bond activation, further optimization studies, and new catalyst design will be topics for further study. The initial results are very
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Published 15 Dec 2016

Copper-catalyzed asymmetric sp3 C–H arylation of tetrahydroisoquinoline mediated by a visible light photoredox catalyst

  • Pierre Querard,
  • Inna Perepichka,
  • Eli Zysman-Colman and
  • Chao-Jun Li

Beilstein J. Org. Chem. 2016, 12, 2636–2643, doi:10.3762/bjoc.12.260

Graphical Abstract
  • process despite the advances that have been made in this field [1]. The directing group strategies are widely used and developed to achieve enantioselective metal-catalyzed C–H bond functionalizations in recent years. Unactivated alkyl C–H bond activation (i.e., without any directing group) is of great
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Published 06 Dec 2016

Radical polymerization by a supramolecular catalyst: cyclodextrin with a RAFT reagent

  • Kohei Koyanagi,
  • Yoshinori Takashima,
  • Takashi Nakamura,
  • Hiroyasu Yamaguchi and
  • Akira Harada

Beilstein J. Org. Chem. 2016, 12, 2495–2502, doi:10.3762/bjoc.12.244

Graphical Abstract
  • , including hydrolysis reactions [10][11][12][13][14][15], C–H bond activation [34][35][36], olefin epoxidation [37][38][39], Diels–Alder reactions [40][41][42], 1,3-dipole cycloadditions [43][44], and polymerizations [45][46][47], among others. Selective substrate recognition and activation are essential
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Published 22 Nov 2016

Regiocontroled Pd-catalysed C5-arylation of 3-substituted thiophene derivatives using a bromo-substituent as blocking group

  • Mariem Brahim,
  • Hamed Ben Ammar,
  • Jean-François Soulé and
  • Henri Doucet

Beilstein J. Org. Chem. 2016, 12, 2197–2203, doi:10.3762/bjoc.12.210

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  • “green” access to arylated thiophene derivatives as it reduces the number of steps to prepare these compounds and also the formation of wastes. Keywords: aryl bromides; C–H bond activation; catalysis; direct arylation; palladium; thiophenes; Introduction Thiophene derivatives bearing aryl substituents
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Published 17 Oct 2016

Cationic Pd(II)-catalyzed C–H activation/cross-coupling reactions at room temperature: synthetic and mechanistic studies

  • Takashi Nishikata,
  • Alexander R. Abela,
  • Shenlin Huang and
  • Bruce H. Lipshutz

Beilstein J. Org. Chem. 2016, 12, 1040–1064, doi:10.3762/bjoc.12.99

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  • Although aromatic C–H bond activation through palladacycle [214] generation is a critical step in the ortho-directed, activation/cross-coupling sequence, many of its specific mechanistic features are still controversial. Previous studies with arylureas [73][206][215] have formulated a palladacycle as the
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Published 20 May 2016

Enantioselective carbenoid insertion into C(sp3)–H bonds

  • J. V. Santiago and
  • A. H. L. Machado

Beilstein J. Org. Chem. 2016, 12, 882–902, doi:10.3762/bjoc.12.87

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  • aryldiazoacetate 21e afforded the insertion product in only 15% yield. In 2013, Davies, Yo et al reported a new strategy to construct 2,3-dihydrobenzofurans based on a sequential enantioselective rhodium catalyzed carbenoid insertion into a C(sp3)–H bond followed by a palladium C(sp2)–H bond activation to build a
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Published 04 May 2016

Recent advances in C(sp3)–H bond functionalization via metal–carbene insertions

  • Bo Wang,
  • Di Qiu,
  • Yan Zhang and
  • Jianbo Wang

Beilstein J. Org. Chem. 2016, 12, 796–804, doi:10.3762/bjoc.12.78

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  • –carbene; site-selectivity; Introduction Direct functionalization of inactivated C–H bonds, especially C(sp3)–H bonds, have attracted significant attentions in recent years. The C(sp3)–H bond activation strategies based on radical reactions and transition metal catalysis have been explored, alongside the
  • development of various directing groups for controlling the site-selectivity of the reaction. Regardless of the great efforts devoted to the field, the intermolecular C(sp3)–H bond activation of simple alkanes still remains a formidable challenge, obviously attributed to the inertness and ubiquitous nature of
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Published 25 Apr 2016

Opportunities and challenges for direct C–H functionalization of piperazines

  • Zhishi Ye,
  • Kristen E. Gettys and
  • Mingji Dai

Beilstein J. Org. Chem. 2016, 12, 702–715, doi:10.3762/bjoc.12.70

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  • , path b). Although there have been major advancements made in the field of direct sp3 C–H bond activation and functionalization adjacent to nitrogen in saturated N-heterocycles and acyclic amines [25][26][27], C–H functionalization of piperazines has been a daunting challenge. In comparison to the well
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Published 13 Apr 2016

C–H bond halogenation catalyzed or mediated by copper: an overview

  • Wenyan Hao and
  • Yunyun Liu

Beilstein J. Org. Chem. 2015, 11, 2132–2144, doi:10.3762/bjoc.11.230

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  • Pd-catalyzed Suzuki–Miyaura reaction. The C–H bond activation process was believed to be initiated by the oxidation effect of the Cu(II) catalyst to give intermediate 54 which was further oxidized to provide cation intermediate 55. The deprotection of 55 gave finally the halogenated products 52
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Published 09 Nov 2015

Efficient synthesis of π-conjugated molecules incorporating fluorinated phenylene units through palladium-catalyzed iterative C(sp2)–H bond arylations

  • Fatiha Abdelmalek,
  • Fazia Derridj,
  • Safia Djebbar,
  • Jean-François Soulé and
  • Henri Doucet

Beilstein J. Org. Chem. 2015, 11, 2012–2020, doi:10.3762/bjoc.11.218

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  • coupling partners. On the other hand, benzenesulfonyl chlorides were recently introduced as powerful arylating agents, through metal-catalyzed C–H bond activation [47][48][49][50][51][52][53][54][55]. Such desulfitative direct arylations sometimes offered different regioselectivities, e.g., thiophenes were
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Published 28 Oct 2015
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