Mechanisms for radical reactions initiating from N-hydroxyphthalimide esters

• Carlos R. Azpilcueta-Nicolas and
• Jean-Philip Lumb

Beilstein J. Org. Chem. 2024, 20, 346–378, doi:10.3762/bjoc.20.35

• intermediacy of free radicals, indicating the involvement of the SET pathway (Scheme 21C). Eventually, reductive elimination of 113 afforded product 114 while regenerating the catalytic species 109. It is worth nothing that further transformations of NHPI esters under photoinduced Cu catalysis have been

On the application of 3d metals for C–H activation toward bioactive compounds: The key step for the synthesis of silver bullets

• Renato L. Carvalho,
• Amanda S. de Miranda,
• Mateus P. Nunes,
• Roberto S. Gomes,
• Guilherme A. M. Jardim and
• Eufrânio N. da Silva Júnior

Beilstein J. Org. Chem. 2021, 17, 1849–1938, doi:10.3762/bjoc.17.126

• using nonprecious Fe and Cu catalysis have been described by Sutherland and co-workers in 2020 (Scheme 32B and C) [165]. Benzofurans are important scaffolds present in several bioactive compounds, such as balsaminone A (91, antipruritic activity), xylarianaphthol-1 (92, anticancer activity), and

When metal-catalyzed C–H functionalization meets visible-light photocatalysis

• Lucas Guillemard and
• Joanna Wencel-Delord

Beilstein J. Org. Chem. 2020, 16, 1754–1804, doi:10.3762/bjoc.16.147

Recent advances in Cu-catalyzed C(sp³)–Si and C(sp³)–B bond formation

• Balaram S. Takale,
• Ruchita R. Thakore,
• Elham Etemadi-Davan and
• Bruce H. Lipshutz

Beilstein J. Org. Chem. 2020, 16, 691–737, doi:10.3762/bjoc.16.67

• silyl ethers 89–92 (Scheme 18), thus showcasing the synergistic relationship between Pd and Cu catalysis [43]. Driven by the success of earlier results, the authors utilized 78 for reductive couplings between ketones 93 and imines 97 as electrophiles to form unsymmetrical 1,2-diols 94–96 and 1,2-amino

• tertiary carbon centers-bearing silicon products, although educts with initial tri-substitution led to lower isolated yields (e.g., 258). An unusual type of reaction has been described in which an acyl silane reacts with 1,3-dienes, under Cu catalysis, leading to an interesting class of α-silyl tertiary

• PhMe2Si group could also be prepared in moderate yield (276). The regiocontrolled ring opening reactions of the same aryl-substituted aziridines 277 have also been shown by Minakata and Takeda et al. to be susceptible to dual Pd/Cu catalysis. Depending upon the ligand on each metal, either the 2 or 3

Combination of multicomponent KA² and Pauson–Khand reactions: short synthesis of spirocyclic pyrrolocyclopentenones

• Riccardo Innocenti,
• Elena Lenci,
• Gloria Menchi and
• Andrea Trabocchi

Beilstein J. Org. Chem. 2020, 16, 200–211, doi:10.3762/bjoc.16.23

• ; chemoinformatics; Cu-catalysis; cycloadditions; molecular scaffolds; multicomponent reactions; Introduction The screening of small molecule libraries is a well-established approach in early-stage drug discovery to identify hit candidates for the development of drug leads. The application of unconventional

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

• merger of photoredox and Cu catalysis (Scheme 21). In this protocol, the CF3 radical was generated by visible light photoredox, then Cu aryl species were generated through Cu catalysis. Aromatic boronic acids bearing either electron-donating or electron-withdrawing substituents underwent

• Cu catalysis. Trifluoromethylation of arylboronic acids reported by Sanford’s group. Isolated yield. aYields determined by 19F NMR analysis. Trifluoromethylation of arylboronic acids and vinylboronic acids reported by the group of Beller. Yields determined by 19F NMR analysis. aGC yield. bIsolated

Transition-metal-free one-pot synthesis of alkynyl selenides from terminal alkynes under aerobic and sustainable conditions

• Adrián A. Heredia and
• Alicia B. Peñéñory

Beilstein J. Org. Chem. 2017, 13, 910–918, doi:10.3762/bjoc.13.92

• under Cu catalysis [26][27][28][29], from terminal alkynes in the presence of bases and Cu [30][31][32][33], Fe [34][35] or In [36] catalysis, or with t-BuOK without of transition metal [37] have been reported. In general, these methodologies require selenyl halides or diselenides as starting materials

Pd- and Cu-catalyzed approaches in the syntheses of new cholane aminoanthraquinone pincer-like ligands

• Nikolay V. Lukashev,
• Gennadii A. Grabovyi,
• Dmitry A. Erzunov,
• Alexey V. Kazantsev,
• Gennadij V. Latyshev,
• Alexei D. Averin and
• Irina P. Beletskaya.

Beilstein J. Org. Chem. 2017, 13, 564–570, doi:10.3762/bjoc.13.55

• )anthraquinones with a series of cations demonstrated their high binding affinity to Cu2+, Al3+, and Cr3+. Keywords: amination; aminocholanes; bile acids; cation complexation; Cu-catalysis; diaminoanthraquinone; Pd-catalysis; Introduction Bile acids are known to ensure vital processes in vertebrate organisms

Palladium-catalyzed picolinamide-directed iodination of remote ortho-C−H bonds of arenes: Synthesis of tetrahydroquinolines

• William A. Nack,
• Xinmou Wang,
• Bo Wang,
• Gang He and
• Gong Chen

Beilstein J. Org. Chem. 2016, 12, 1243–1249, doi:10.3762/bjoc.12.119

• arylation of 1 with para-diiodobenzene under the standard arylation conditions gave 25 in moderate yield. Iodination of 25 via PA-directed SEAr gave diiodinated compound 26, which was cyclized under Cu catalysis to give 7-iodo-THQ 30 in good yield. The PA group of 8-iodo-THQ 29 was readily removed with

Base metal-catalyzed benzylic oxidation of (aryl)(heteroaryl)methanes with molecular oxygen

• Hans Sterckx,
• Johan De Houwer,
• Carl Mensch,
• Wouter Herrebout,
• Kourosch Abbaspour Tehrani and
• Bert U. W. Maes

Beilstein J. Org. Chem. 2016, 12, 144–153, doi:10.3762/bjoc.12.16

• expects the tautomerization to proceed more efficiently when the pyridine nitrogen becomes more basic and the methylene hydrogen becomes more acidic. In Table 2 the results on pyridine-substituted 2-benzylpyridines using both Fe and Cu catalysis are shown. Under the standard conditions only a small number

• Cu catalysis were obtained after 24 h, CuI was selected for this purpose. The reasoning behind this is reflected in the chemoselectivity experiments (vide infra), where it was shown that CuI is a slightly more potent catalyst than FeCl2·4H2O. Additionally, comparison of the reaction rate for both

• -tolyl)methanone (19a) in 57% yield (Table 5, entry 2). A similar chemoselectivity was observed for the oxidation of 18b where Cu catalysis lead to bis-oxidation (20b, Table 5, entry 4) while Fe catalysis resulted in mono-oxidation (19b, Table 5, entry 5). When the reaction with 18a using Cu catalysis is

Copper-catalysed asymmetric allylic alkylation of alkylzirconocenes to racemic 3,6-dihydro-2H-pyrans

• Emeline Rideau and
• Stephen P. Fletcher

Beilstein J. Org. Chem. 2015, 11, 2435–2443, doi:10.3762/bjoc.11.264

• became clear that when using alkylzirconocene nucleophiles and Cu catalysis, derivatised 3,6-dihydro-2H-pyrans are difficult to obtain in high enantiomeric excess. Moreover, both optimised systems gave poor yield; 25% yield with 100% conversion from allyl chloride 2a and 17% yield with 31% conversion

Practical synthesis of aryl-2-methyl-3-butyn-2-ols from aryl bromides via conventional and decarboxylative copper-free Sonogashira coupling reactions

• Andrea Caporale,
• Stefano Tartaggia,
• Andrea Castellin and
• Ottorino De Lucchi

Beilstein J. Org. Chem. 2014, 10, 384–393, doi:10.3762/bjoc.10.36

• ][11][12][13]. The Sonogashira coupling reaction is usually carried out under Pd/Cu catalysis, in which the palladium has the function to promote the cross-coupling of an aryl fragment, added via oxidative addition of the corresponding halide, with an alkynyl residue to provide a disubstituted

Recent advances in transition metal-catalyzed Csp²-monofluoro-, difluoro-, perfluoromethylation and trifluoromethylthiolation

• Grégory Landelle,
• Armen Panossian,
• Sergiy Pazenok,
• Jean-Pierre Vors and
• Frédéric R. Leroux

Beilstein J. Org. Chem. 2013, 9, 2476–2536, doi:10.3762/bjoc.9.287

• monofluoromethylation was described by J. Hu. Aryl iodides were submitted to a Cu-catalyzed (CuTC = copper thiophene-2-carboxylate) debenzoylative fluoroalkylation with 2-PySO2CHFCOR followed by desulfonylation (Scheme 2) [49]. It has been shown that the (2-pyridyl)sulfonyl moiety is important for the Cu-catalysis. 2

Efficient Cu-catalyzed base-free C–S coupling under conventional and microwave heating. A simple access to S-heterocycles and sulfides

• Silvia M. Soria-Castro and
• Alicia B. Peñéñory

Beilstein J. Org. Chem. 2013, 9, 467–475, doi:10.3762/bjoc.9.50

• h at 110 °C, has also been reported [52]. As part of our ongoing study on sulfur chemistry, we are interested in the one-pot synthesis of target heterocycles such as the Beaucage reagent and benzothiazole as well as sulfides by using Cu-catalysis to mediate the C–S bond formation. Herein, we report

Combined directed ortho-zincation and palladium-catalyzed strategies: Synthesis of 4,n-dimethoxy-substituted benzo[b]furans

• Verónica Guilarte,
• M. Pilar Castroviejo,
• Estela Álvarez and
• Roberto Sanz

Beilstein J. Org. Chem. 2011, 7, 1255–1260, doi:10.3762/bjoc.7.146

• required position (o,o-disubstituted) we employed a copper- and solvent-free methodology for the Sonogashira coupling that uses tetrabutylammonium fluoride as base [42] (Table 2, method A). Subsequently, we checked that the selective coupling could be carried out under standard Pd–Cu catalysis by

C–C (alkynylation) vs C–O (ether) bond formation under Pd/C–Cu catalysis: synthesis and pharmacological evaluation of 4-alkynylthieno[2,3-d]pyrimidines

• Dhilli Rao Gorja,
• K. Shiva Kumar,
• K. Mukkanti and
• Manojit Pal

Beilstein J. Org. Chem. 2011, 7, 338–345, doi:10.3762/bjoc.7.44

• position of a thieno[2,3-d]pyrimidine ring via C–C coupling under Pd/C–Cu catalysis. To the best of our knowledge, only two examples of similar coupling have been reported using the system (PPh3)2PdCl2/CuI as catalyst in the presence of Et3N [10]. The alkynyl substituent of compound 3 could be utilized for

• –Cu catalysis. Plausible mechanism of Pd/C-mediated alkynylation of 4-chlorothieno[2,3-d]pyrimidines 1. Effect of solvent on the coupling reaction of 4-chloro-5,6,7,8-tetrahydrobenzothieno[2,3-d]pyrimidine (1a) with phenylacetylene (2a).a Pd/C-mediated synthesis of 4-alkynylthieno[2,3-d]pyrimidine in

Pd/C-mediated synthesis of α-pyrone fused with a five-membered nitrogen heteroaryl ring: A new route to pyrano[4,3-c]pyrazol-4(1H)-ones

• Dhilli Rao Gorja,
• Venkateswara Rao Batchu,
• Ashok Ettam and
• Manojit Pal

Beilstein J. Org. Chem. 2009, 5, No. 64, doi:10.3762/bjoc.5.64

• ]. On the other hand construction of a pyridine ring on a pyrazole moiety has been described under Ni or Pd catalysis [19]. Herein we report the first construction of an α-pyrone ring on a pyrazol moiety leading to the synthesis of 6-substituted pyrano[4,3-c]pyrazol-4(1H)-one 3 under Pd/C-Cu catalysis

• pyrano[4,3-c]pyrazol-4(1H)-ones under Pd/C-Cu catalysis, preparation of which would be difficult via other methods. The reaction proceeds via tandem C-C and C-O bond formation between the 5-iodopyrazole-4-carboxylic acid and a terminal alkyne in the same pot. Being an integral part of many drugs or

Dimerization of propargyl and homopropargyl 6-azido- 6-deoxy- glycosides upon 1,3-dipolar cycloaddition

• Nikolas Pietrzik,
• Daniel Schmollinger and
• Thomas Ziegler

Beilstein J. Org. Chem. 2008, 4, No. 30, doi:10.3762/bjoc.4.30

• glycosylated building blocks for the combinatorial synthesis of glycopeptides. Synthesis and reaction of compounds 4a and 4a'. Preparation of compounds 4a–g. Dimerization of Glycosides 4a–g under Cu-Catalysis. Supporting Information Supporting Information File 76: Experimental Data Acknowledgements This work