Copper-catalyzed O-alkenylation of phosphonates

• Nuria Vázquez-Galiñanes,
• Mariña Andón-Rodríguez,
• Patricia Gómez-Roibás and
• Martín Fañanás-Mastral

Beilstein J. Org. Chem. 2020, 16, 611–615, doi:10.3762/bjoc.16.56

• /bjoc.16.56 Abstract Copper catalysis allows the direct oxygen alkenylation of dialkyl phosphonates with alkenyl(aryl)iodonium salts with selective transfer of the alkenyl group. This novel methodology proceeds with a wide range of phosphonates under mild conditions and gives straightforward access to

• (alkenyl)iodonium salts, which are air- and moisture-stable, nontoxic and easy to prepare compounds, have become efficient reagents for mild and selective arylation and alkenylation reactions in organic synthesis [16][17][18]. In particular, the use of these hypervalent iodine reagents in copper catalysis

Copper-catalyzed enantioselective conjugate reduction of α,β-unsaturated esters with chiral phenol–carbene ligands

• Shohei Mimura,
• Sho Mizushima,
• Yohei Shimizu and
• Masaya Sawamura

Beilstein J. Org. Chem. 2020, 16, 537–543, doi:10.3762/bjoc.16.50

• catalyst worked well for various (Z)-isomer substrates. Opposite enantiomers were obtained from (Z)- and (E)-isomers, with a higher enantiomeric excess from the (Z)-isomer. Keywords: catalyst; chiral NHC; conjugate reduction; copper catalysis; enantioselective reaction; Introduction Since the leading

Copper-catalyzed remote C–H arylation of polycyclic aromatic hydrocarbons (PAHs)

• Anping Luo,
• Min Zhang,
• Zhangyi Fu,
• Jingbo Lan,
• Di Wu and
• Jingsong You

Beilstein J. Org. Chem. 2020, 16, 530–536, doi:10.3762/bjoc.16.49

• arylation; nonprecious metal catalyst; copper catalysis; polycyclic aromatic hydrocarbons (PAHs); regioselectivity; Introduction Polycyclic aromatic hydrocarbons (PAHs) with rigid planar structure, such as naphthalene, phenanthrene, pyrene and their derivatives, can usually emit relatively strong

Aerobic synthesis of N-sulfonylamidines mediated by N-heterocyclic carbene copper(I) catalysts

• Faïma Lazreg,
• Marie Vasseur,
• Alexandra M. Z. Slawin and
• Catherine S. J. Cazin

Beilstein J. Org. Chem. 2020, 16, 482–491, doi:10.3762/bjoc.16.43

• : catalysis; copper; copper catalysis; N-heterocyclic carbene; solvent-free; sulfonylamidines; Introduction Amide derivatives represent a ubiquitous molecular construct in chemistry [1][2][3]. This structural motif favours rearrangements that lead to high reactivity and associated bioactivity [4][5]. Indeed

Recent advances in photocatalyzed reactions using well-defined copper(I) complexes

• Mingbing Zhong,
• Xavier Pannecoucke,
• Philippe Jubault and
• Thomas Poisson

Beilstein J. Org. Chem. 2020, 16, 451–481, doi:10.3762/bjoc.16.42

• in photocatalysis using copper complexes. Their applications in various reactions, such as ATRA, reduction, oxidation, proton-coupled electron transfer, and energy transfer reactions are discussed. Keywords: ATRA reactions; copper catalysis; energy transfer; oxidation; PCET reactions; photocatalysis

Copper-promoted/copper-catalyzed trifluoromethylselenolation reactions

• Clément Ghiazza and
• Anis Tlili

Beilstein J. Org. Chem. 2020, 16, 305–316, doi:10.3762/bjoc.16.30

• Clement Ghiazza Anis Tlili Institute of Chemistry and Biochemistry, Univ Lyon, Université Lyon 1, CNRS, 43 Bd du 11 Novembre 1918, F-69622 Villeurbanne, France 10.3762/bjoc.16.30 Abstract Copper catalysis and, more generally, copper chemistry are pivotal for modern organofluorine chemistry. Major

• advances have been made in the field of trifluoromethylselenolations of organic compounds where copper catalysis played a crucial role. Recent developments in this field are highlighted in this minireview. Keywords: copper catalysis; fluorine; homogenous catalysis; trifluoromethylselenolation

• , the incorporation of OCF3 as well as SCF3 is routinely used to design new active compounds [8]. The development of new methodologies based on copper catalysis/chemistry is playing a pivotal role due to the low cost and toxicity of the corresponding copper reagents [9]. Due to their stability, these

Copper-catalyzed enantioselective conjugate addition of organometallic reagents to challenging Michael acceptors

• Delphine Pichon,
• Jennifer Morvan,
• Christophe Crévisy and
• Marc Mauduit

Beilstein J. Org. Chem. 2020, 16, 212–232, doi:10.3762/bjoc.16.24

• accomplished in this stimulating field. Keywords: acylimidazole; N-acyloxazolidinone; N-acylpyrrole; N-acylpyrrolidinone; aldehyde; amide; copper catalysis; electron-deficient alkenes; enantioselective conjugate addition; Michael acceptor; thioester; Introduction Generating high molecular complexity and

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

• following the reported method [48] employing copper catalysis, and tested on our starting material upon variation of copper salts, solvents and temperature, resulting in the neat reaction under CuI catalysis being optimal when carried out for 2 h at 100 °C under microwave irradiation (see Supporting

Allylic cross-coupling using aromatic aldehydes as α-alkoxyalkyl anions

• Akihiro Yuasa,
• Kazunori Nagao and
• Hirohisa Ohmiya

Beilstein J. Org. Chem. 2020, 16, 185–189, doi:10.3762/bjoc.16.21

• -catalyzed allylic substitution. Keywords: aldehyde; copper; copper catalysis; cross-coupling; palladium; synthetic method; Introduction α-Alkoxy-substituted carbanions (α-alkoxyalkyl anions) are useful C(sp3) nucleophiles for the construction of alcohol units found in a majority of pharmaceuticals

• carbonates having a fluoro or acetal substituent were also suitable coupling partners (3ad and 3ae). The synergistic palladium/copper catalysis was used for the reaction of a secondary allylic carbonate. For example, the allylic cross-coupling of 2a’, a constitutional isomer of 2a, with benzaldehyde (1a

• and the outcome obtained by the stoichiometric experiment in Scheme 4, a possible reaction pathway involving a cooperative action of palladium and copper catalysis can be proposed as illustrated in Scheme 5. The reaction of SIPr-ligated CuCl (A), KOt-Bu and a silylboronate produces a silylcopper(I

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

• ]. Additionally, a diverse range of N-heterocycles, amides and motifs commonly encountered in medicinal chemistry were used as handles to direct C–H fluorination for the synthesis of pharmaceutical drugs (Scheme 24) [25]. Copper catalysis Despite the success of Pd-catalyzed fluorinations, the more widespread use

• catalyzed by metals. However, there are only a few methods available for the C(sp3)–CF3 bond formation and this transformation still needs further examination. C(sp3)–CF3 bond formation Copper catalysis: In 2011, two Cu(I)-catalyzed allylic trifluoromethylation reactions of terminal olefins have been

• oxidative decarboxylation. Then, Cu(CF3)2 provides a CF3 group to alkyl radicals to obtain the final product. Very recently, MacMillan et al. [120] discovered an efficient approach to the decarboxylative trifluoromethylation of aliphatic carboxylic acids via the combination of photoredox and copper

Synthesis of aryl cyclopropyl sulfides through copper-promoted S-cyclopropylation of thiophenols using cyclopropylboronic acid

• Emeline Benoit,
• Ahmed Fnaiche and
• Alexandre Gagnon

Beilstein J. Org. Chem. 2019, 15, 1162–1171, doi:10.3762/bjoc.15.113

• thiophenol was also accomplished using potassium cyclopropyl trifluoroborate. Keywords: aryl cyclopropyl sulfides; copper(II) acetate; copper catalysis; cyclopropylboronic acid; thiophenols; Introduction Aryl cyclopropyl sulfides are present in many biologically active compounds, mainly in their oxidized

Multicomponent reactions (MCRs): a useful access to the synthesis of benzo-fused γ-lactams

• Edorta Martínez de Marigorta,
• Jesús M. de Los Santos,
• Ana M. Ochoa de Retana,
• Javier Vicario and
• Francisco Palacios

Beilstein J. Org. Chem. 2019, 15, 1065–1085, doi:10.3762/bjoc.15.104

• copper catalysis to furnish several propargylisoindolinones 30 with modest to good yields (Scheme 7) [81]. Although aryl- and alkylacetylenes can be used in this method, only aromatic amines 2 which are not ortho-substituted work well under these reaction conditions. The reaction probably takes place

• be isolated. Finally, cyclopropyl ketone 91 would first rearrange by copper catalysis and the so-obtained furane derivative 96 would add to the carbocation in 95, followed by Friedel–Crafts cyclization, thus generating the polycyclic isoindolinones 92 in a formal hetero [4 + 2] cycloaddition process

• prepared by another type of three-component approach, in this case under copper catalysis (Scheme 35) [112]. The partners of the reaction are N-(arylsulfonyl)acrylamides 123, aryldiazonium tetrafluoroborates 68 and DABCO·(SO2)2 (69), as a source of sulfur dioxide. In this way, sulfonated oxindoles 124 are

Tandem copper and photoredox catalysis in photocatalytic alkene difunctionalization reactions

• Nicholas L. Reed,
• Madeline I. Herman,
• Vladimir P. Miltchev and
• Tehshik P. Yoon

Beilstein J. Org. Chem. 2019, 15, 351–356, doi:10.3762/bjoc.15.30

• enantioselective by utilizing chiral Cu(II) complexes have thus far not been successful. A screen of several classes of privileged ligands for asymmetric copper catalysis produced only racemic oxyamination products. We interpret this observation as an indication that Cu(II) is unable to control the stereochemistry

Copper(I)-catalyzed tandem reaction: synthesis of 1,4-disubstituted 1,2,3-triazoles from alkyl diacyl peroxides, azidotrimethylsilane, and alkynes

• Muhammad Israr,
• Changqing Ye,
• Munira Taj Muhammad,
• Yajun Li and
• Hongli Bao

Beilstein J. Org. Chem. 2018, 14, 2916–2922, doi:10.3762/bjoc.14.270

• ; copper catalysis; radical; 1,2,3-triazoles; Introduction The “click chemistry”, coined by K. B. Sharpless in 2001 [1], is a powerful chemical transformation that has rapidly orthogonalized traditional disciplinary boundaries. With the discovery of “click chemistry”, new fields have been opened for the

Atom-economical group-transfer reactions with hypervalent iodine compounds

• Andreas Boelke,
• Peter Finkbeiner and
• Boris J. Nachtsheim

Beilstein J. Org. Chem. 2018, 14, 1263–1280, doi:10.3762/bjoc.14.108

• [31]. Under copper-catalysis diarylated isoindolin-1-ones 9 were formed starting from 2-formylbenzonitriles 8 upon treatment with mesityl(aryl)iodonium salts 1a (Scheme 6). A plausible reaction mechanism starts with the selective terminal arylation of the nitrile, forming the arylnitrilium cation A

• ]. A selective C–H arylation at C3 of the indole was realised under copper catalysis before the addition of a ligand and an inorganic base initiated the N-arylation with the in situ formed iodoarene. The desired diarylated indoles 11 are obtained with an AE of 46% (for R1 = R2 = H, Ar1 = Ar2 = Ph). The

Rhodium-catalyzed C–H functionalization of heteroarenes using indoleBX hypervalent iodine reagents

• Erwann Grenet,
• Ashis Das,
• Paola Caramenti and
• Jérôme Waser

Beilstein J. Org. Chem. 2018, 14, 1208–1214, doi:10.3762/bjoc.14.102

• transformations [22], but only one application of indole iodonium salts in copper catalysis by You and co-workers had been reported until 2017 [23]. In this context, indole-based benziodoxole hypervalent iodine reagents, recently introduced by Yoshikai's and our group [24][25][26][27], appeared ideal partners to

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

• trifluoromethyl groups into organic molecules has attracted great attention in the past five years. In this review, we describe the recent efforts in the development of trifluoromethylation via copper catalysis using nucleophilic, electrophilic or radical trifluoromethylation reagents. Keywords: copper; fluorine

Direct catalytic arylation of heteroarenes with meso-bromophenyl-substituted porphyrins

• Alexei N. Kiselev,
• Olga K. Grigorova,
• Alexei D. Averin,
• Sergei A. Syrbu,
• Oskar I. Koifman and
• Irina P. Beletskaya

Beilstein J. Org. Chem. 2017, 13, 1524–1532, doi:10.3762/bjoc.13.152

• our purpose, while the third system proved to be most versatile and afforded corresponding mono-, di-, tri- and even tetraarylated derivatives of porphyrins. Keywords: arylation; copper catalysis; heteroarenes; palladium catalysis; porphyrins; Introduction Porphyrins play an outstanding role in many

Application of Cu(I)-catalyzed azide–alkyne cycloaddition for the design and synthesis of sequence specific probes targeting double-stranded DNA

• Svetlana V. Vasilyeva,
• Vyacheslav V. Filichev and
• Alexandre S. Boutorine

Beilstein J. Org. Chem. 2016, 12, 1348–1360, doi:10.3762/bjoc.12.128

• succeeded to obtain a conjugate of two polyamides by template-directed synthesis on the adjacent sequences of a target DNA fragment using the Huisgen 1,3-cycloaddition reaction even without copper catalysis [39]. The rational for this type of synthesis was to find an optimal orientation of two DNA-binding

• ligands for the synthesis of highly affine conjugates and to provide a favorable approaching and orientation of the two components in order to facilitate the reaction. However, after this publication the use of a Huisgen reaction without copper catalysis in the template-directed synthesis was never

• template, 2) Template duplex + TFO + polyamide without copper catalysys, 3) TFO + MGB, no template, with copper catalysis, 4) Template duplex + TFO + polyamide with copper catalysis. Initially, a triplex was formed by mixing and incubation of the duplex with the TINA-TFO, then polyamide and Cu(I) with

Creating molecular macrocycles for anion recognition

• Amar H. Flood

Beilstein J. Org. Chem. 2016, 12, 611–627, doi:10.3762/bjoc.12.60

• it was an old reaction, the Huisgen cycloaddition, made good (regioselective) with the aid of copper catalysis. Taking that idea on face value, I reasoned that click chemistry was a new and extremely effective way to make 1,2,3-triazoles. It is not often that either new or newly refined reactions

Copper-mediated arylation with arylboronic acids: Facile and modular synthesis of triarylmethanes

• H. Surya Prakash Rao and
• A. Veera Bhadra Rao

Beilstein J. Org. Chem. 2016, 12, 496–504, doi:10.3762/bjoc.12.49

• carbon can be assembled in a two-step protocol, is modular in nature. The first step is the synthesis of diarylmethanol and the second step is the replacement of the hydroxy group in the resulting diarylmethanol by a third aryl group by employing arylboronic acid under copper catalysis. As a proof of

Synthesis of bi- and bis-1,2,3-triazoles by copper-catalyzed Huisgen cycloaddition: A family of valuable products by click chemistry

• Zhan-Jiang Zheng,
• Ding Wang,
• Zheng Xu and
• Li-Wen Xu

Beilstein J. Org. Chem. 2015, 11, 2557–2576, doi:10.3762/bjoc.11.276

• , powder or nanoparticles) in the presence or absence of Cu(II) in aqueous media also provides the key active Cu(I) in some CuAAC reactions. As an important supplement to the classic Huisgen cycloaddition promoted by copper catalysis, this review will deal with the copper-catalyzed syntheses of bi- and

Copper-catalyzed stereoselective conjugate addition of alkylboranes to alkynoates

• Takamichi Wakamatsu,
• Kazunori Nagao,
• Hirohisa Ohmiya and
• Masaya Sawamura

Beilstein J. Org. Chem. 2015, 11, 2444–2450, doi:10.3762/bjoc.11.265

• the present copper catalysis is proposed in Figure 1. An alkoxycopper complex (A) is initially formed by the reaction of CuOAc, t-BuOK and P(OPh)3. Boron-to-cupper transmetalation between A and the alkylborane 2 occurs to form an alkylcopper(I) species (B) and a t-butoxyborane (9-BBN-Ot-Bu) [12][13

Cu(I)-catalyzed N,N’-diarylation of natural diamines and polyamines with aryl iodides

• Svetlana P. Panchenko,
• Alexei D. Averin,
• Maksim V. Anokhin,
• Olga A. Maloshitskaya and
• Irina P. Beletskaya

Beilstein J. Org. Chem. 2015, 11, 2297–2305, doi:10.3762/bjoc.11.250

• of diamines and spermine while the CuI/L-proline/EtCN system proved to be preferable for the diarylation of other tri- and tetraamines like spermidine, norspermidine and norspermine. Keywords: amination; aryl amines; aryl iodides; copper catalysis; polyamines; Introduction Natural diamines and

Recent developments in copper-catalyzed radical alkylations of electron-rich π-systems

• Kirk W. Shimkin and
• Donald A. Watson

Beilstein J. Org. Chem. 2015, 11, 2278–2288, doi:10.3762/bjoc.11.248

• nitroalkanes using palladium catalysis were known, prior to our work, no general catalytic methods for the alkylation of nitroalkanes existed. We envisioned that the catalytic generation of an alkyl radical under copper catalysis in the presence of a nitronate anion could lead to C-alkylated products. In

• dihydrofurans could be easily converted into furans using DDQ in a one-pot process. In addition to α-bromo esters and ketones, Lei and co-workers have also recently shown that benzylic halides could undergo radical alkenylation via copper catalysis [39]. By exploiting the propensity of benzyl halides to form

• benzyl radicals under copper catalysis, an alkenylation similar to that developed by Nishikata was realized. Using a mixture of copper and 1,10-phenanthroline, benzylic halides were directly alkenylated using styrenes as coupling partners. Under these conditions, various allylbenzene derivatives were