Copper-catalyzed aminooxygenation of styrenes with N-fluorobenzenesulfonimide and N-hydroxyphthalimide derivatives

• Yan Li,
• Xue Zhou,
• Guangfan Zheng and
• Qian Zhang

Beilstein J. Org. Chem. 2015, 11, 2721–2726, doi:10.3762/bjoc.11.293

• Yan Li Xue Zhou Guangfan Zheng Qian Zhang Department of Chemistry, Northeast Normal University, Changchun 130024, China 10.3762/bjoc.11.293 Abstract A copper-catalyzed aminooxygenation reaction of styrenes with N-fluorobenzenesulfonimide and N-hydroxyphthalimide derivatives has been developed

• modes of NFSI [37][38][39][40][41], especially as a nitrogen-centred radical. In this context, we have realized copper-catalyzed benzylic sp3 C–H amination [42], aminative multiple functionalization of alkynes [43], diamination, aminocyanation [44] and aminofluorination of alkenes [45], as well as

• amination of allenes [46]. Encouraged by these results, we try to develop copper-catalyzed aminooxygenation of alkenes by using NFSI. Herein, we report a simple and efficient copper-catalyzed three-component aminooxygenation reaction of styrenes with NFSI and N-hydroxyphthalimide (NHPI) derivatives (Scheme

Enantioselective additions of copper acetylides to cyclic iminium and oxocarbenium ions

• Jixin Liu,
• Srimoyee Dasgupta and
• Mary P. Watson

Beilstein J. Org. Chem. 2015, 11, 2696–2706, doi:10.3762/bjoc.11.290

• Jixin Liu Srimoyee Dasgupta Mary P. Watson Department of Chemistry and Biochemistry, University of Delaware, Newark, DE 19716, USA 10.3762/bjoc.11.290 Abstract The development of enantioselective, copper-catalyzed alkynylations of cyclic iminium and oxocarbenium ions is reviewed. The use of

• -based catalysts [9][10][11][12][13][14][15]. Among these, chiral copper catalysts have been used with remarkable success in the alkynylation of cyclic iminium ion and oxocarbenium ion intermediates. This review will focus on the development of these enantioselective, copper-catalyzed alkynylations

• , highlighting both the accomplishments and the future work needed in this important area. Throughout the discussion below, it is clear that there are privileged ligand architectures of these copper-catalyzed alkynylations. High enantioselectivities have been achieved with pyridine bis(oxazoline) (Pybox), bis

Carbon–carbon bond cleavage for Cu-mediated aromatic trifluoromethylations and pentafluoroethylations

• Tsuyuka Sugiishi,
• Hideki Amii,
• Kohsuke Aikawa and
• Koichi Mikami

Beilstein J. Org. Chem. 2015, 11, 2661–2670, doi:10.3762/bjoc.11.286

• − sources for perfluoroalkylation reactions. Furthermore, CF3Cu and C2F5Cu were utilized for oxidative perfluoroalkylation reactions of arylboronic acids [44][45] (Scheme 13). Copper-catalyzed group transfer from fluoral derivatives Catalytic systems in organic synthesis are desirable from an

• environmentally benign point of view. With regard to aromatic trifluoromethylation, the effort is devoted to reduce the copper reagents employed in the reactions. Copper-catalyzed aromatic trifluoromethylation with CF3SiMe3 was developed using phen as a ligand [50]. On the other hand, Billard and Langlois et al

• . described silylated hemiaminals of fluoral (trifluoroacetaldehyde) that act as a nucleophilic trifluoromethyl source for electrophiles such as aldehydes and ketones [51][52] (Scheme 14). Amii and co-workers reported a copper-catalyzed aromatic trifluoromethylation from silylated hemiaminals of fluoral [53

Recent advances in copper-catalyzed asymmetric coupling reactions

• Fengtao Zhou and
• Qian Cai

Beilstein J. Org. Chem. 2015, 11, 2600–2615, doi:10.3762/bjoc.11.280

• construction of heteroatom-containing ring systems. This review summarizes the recent progress in copper-catalyzed asymmetric coupling reactions for the formation of C–C and carbon–heteroatom bonds. Keywords: asymmetric; carbon–heteroatom bond; copper; coupling; Introduction Copper-mediated coupling

• ][8][9][10][11][12][13]. Despite the progress in recent years, the research on asymmetric coupling reactions is still relatively rare. In this review, we highlight the developments in copper-catalyzed asymmetric coupling reactions, including the asymmetric coupling of aryl halides with nucleophiles

• for the formation of carbon–carbon and carbon–heteroatom bonds as well as the asymmetric allylic substitution with a wide range of nucleophiles for the formation of C–C and carbon–heteroatom bonds. Review Copper-catalyzed coupling of aryl halides with nucleophiles Chiral auxiliary-induced aryl C–C

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

• low yield when the alkynes or azides were linked directly with a hindered group or an aromatic moiety. In 2012, Xu and co-workers disclosed that both the secondary and primary amine-functionalized polysiloxanes were good ligands for the copper-catalyzed Huisgen reaction of organic azides and alkynes

• , Mohammed and co-workers selected the commercially available D-mannitol 38 as the starting material [33] in this reaction. After protection and introduction of the two alkyne groups to give dialkyne 39, the copper-catalyzed cycloaddition occurred smoothly with the different long chain alkyl azides under the

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

• Takamichi Wakamatsu Kazunori Nagao Hirohisa Ohmiya Masaya Sawamura Department of Chemistry, Faculty of Science, Hokkaido University, Sapporo 060-0810, Japan 10.3762/bjoc.11.265 Abstract A copper-catalyzed conjugate addition of alkylboron compounds (alkyl-9-BBN, prepared by hydroboration of

• and their compatibility with a multitude of functional groups, organoboron compounds are especially popular organometallic reagents. Recently, Yamamoto and co-workers developed copper-catalyzed conjugate additions of aryl- and allylboron compounds to alkynoates [9][10], but alkylboron compounds have

• not been used for these methods [11]. As related studies we reported earlier the copper-catalyzed conjugate addition of alkylboranes (alkyl-9-BBN) to imidazole-2-yl α,β-unsaturated ketones [12][13][14] and the copper-catalyzed three-component coupling with alkylboranes, alkynoates, and tributyltin

Copper-catalyzed asymmetric conjugate addition of organometallic reagents to extended Michael acceptors

• Thibault E. Schmid,
• Sammy Drissi-Amraoui,
• Christophe Crévisy,
• Olivier Baslé and
• Marc Mauduit

Beilstein J. Org. Chem. 2015, 11, 2418–2434, doi:10.3762/bjoc.11.263

• Chimie, 8 Rue de l’Ecole Normale, 34296 Montpellier Cedex 5, France 10.3762/bjoc.11.263 Abstract The copper-catalyzed asymmetric conjugate addition (ACA) of nucleophiles onto polyenic Michael acceptors represents an attractive and powerful methodology for the synthesis of relevant chiral molecules, as

• provided dramatic breakthroughs during the last two decades. This review aims to describe the early examples and recent advances in copper-catalyzed asymmetric conjugate additions of organometallic reagents to extended Michael acceptors. First, seminal reports dealing with the reactivity of extended

• co-workers discovered in 2001 the first example of copper-catalyzed enantioselective 1,6-conjugate addition [16]. Using phosphoramidite ligand (S,R,R)-L1 and Cu(OTf)2 as the copper source, diethylzinc was added to dienone 16 with a full 1,6-regioselectivity, and an ee of 35% (Scheme 1). In 2006

Copper-catalyzed arylation of alkyl halides with arylaluminum reagents

• Bijay Shrestha and
• Ramesh Giri

Beilstein J. Org. Chem. 2015, 11, 2400–2407, doi:10.3762/bjoc.11.261

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

• iodides in the copper-catalyzed amination of di- and polyamines providing mainly N-monoaryl derivatives [31]. On the basis of our recent investigations, in order to obtain N,N’-diaryl derivatives, we employed the most suitable catalytic systems, CuI/L-proline (L1) and CuI/2-(isobutyryl)cyclohexanone (L2

• )-catalysis conditions is a more challenging task than N,N’-diarylation of diamines because copper-catalyzed amination is less selective than palladium-catalyzed coupling. In view of earlier obtained data we used the CuI/L1/EtCN catalytic system for the diarylation of the triamine 5 (Scheme 5, Table 4). In

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

• Kirk W. Shimkin Donald A. Watson Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, United States 10.3762/bjoc.11.248 Abstract Recently, a number of papers have emerged demonstrating copper-catalyzed alkylation reactions of electron-rich small molecules. The

• the most common and effective [14]. Recently, several groups, including our own, have developed copper-catalyzed alkylation reactions of molecules containing electron-rich π-systems. These reactions all utilize alkyl halides as the alkylating agent, and deliver reactivity that is not observed in the

• non-catalyzed reactions. Mechanistically, it is believed that these reactions all share features of classic ATR reactions, but are distinct as they deliver simple alkylation products. These transformations represent a new paradigm in copper-catalyzed radical reactions. This article will highlight

Copper catalysis in organic synthesis

• Sherry R. Chemler

Beilstein J. Org. Chem. 2015, 11, 2252–2253, doi:10.3762/bjoc.11.244

• also an essential element, responsible for important biological processes. The title of this Thematic Series published in the Beilstein Journal of Organic Chemistry is “Copper catalysis in organic synthesis”. A web of scienceTM topic search of “copper-catalyzed synthesis” indicated over 500 papers had

• . Some of the most highly cited papers of all time on this topic are reviews on conjugate addition, cross-coupling, and [3 + 2] “Click” reaction applied to bioconjugation. The growth in copper-catalyzed organic reactions may be driven by a couple of factors. First, copper chemistry is incredibly diverse

• field of copper-catalysis from 7 countries make up this Thematic Series, “Copper catalysis in organic synthesis”. Contributions include authoritative reviews on the latest developments in copper-catalyzed Click applications, C–N cross-coupling, C–H functionalization, trifluoromethylations, asymmetric

Recent advances in copper-catalyzed C–H bond amidation

• Jie-Ping Wan and
• Yanfeng Jing

Beilstein J. Org. Chem. 2015, 11, 2209–2222, doi:10.3762/bjoc.11.240

• copper catalysis is in the C–N bond formation by using carbon sources and nitrogen functional groups such as amides. In this review, the recent progress in the amidation reactions employing copper-catalyzed C–H amidation is summarized. Keywords: amidation; C–H bond; cascade reactions; Copper catalysis

• to be capable of catalyzing the C–H amidation reactions, copper is particularly advantageous because of the low cost, low toxicity and broad tolerance of copper catalysts. Therefore, the present review summarizes the advances on the copper-catalyzed C–H activation-based amidation (including related

• ] reported the copper-catalyzed, tert-butyl hydroperoxide (TBHP)-assisted C–H amidation of tertiary amines 1. By heating at 80 °C, the C–H bond in dimethylaniline underwent direct amidation to provide products 3 in the presence of amides 2. On the other hand, the dephenylation transformation via C–C bond

Molecular-oxygen-promoted Cu-catalyzed oxidative direct amidation of nonactivated carboxylic acids with azoles

• Wen Ding,
• Shaoyu Mai and
• Qiuling Song

Beilstein J. Org. Chem. 2015, 11, 2158–2165, doi:10.3762/bjoc.11.233

• Sciences, Beijing, 100190, P. R. China 10.3762/bjoc.11.233 Abstract A copper-catalyzed oxidative direct formation of amides from nonactivated carboxylic acids and azoles with dioxygen as an activating reagent is reported. The azole amides were produced in good to excellent yields with a broad substrate

• [25][26]. Currently, copper-catalyzed, aerobic, oxidative transformations with dioxygen as the sole oxidant have emerged as a useful and powerful strategy to construct carbon–carbon and carbon–heteroatom bonds [27][28][29]. It is known that Cu(II) superoxide species are usually reported to be formed

• ), inexpensive and readily available pyridine was employed as both the ligand and base in our case. Results and Discussion Our initial exploration commenced with benzoic acid (1) and benzimidazole (2) as the model substrates to investigate the copper-catalyzed oxidative direct amidation reaction (Table 1). The

Coupling of α,α-difluoro-substituted organozinc reagents with 1-bromoalkynes

• Artem A. Zemtsov,
• Alexander D. Volodin,
• Vitalij V. Levin,
• Marina I. Struchkova and
• Alexander D. Dilman

Beilstein J. Org. Chem. 2015, 11, 2145–2149, doi:10.3762/bjoc.11.231

• . Conclusion In summary, a method for the copper-catalyzed coupling of α,α-difluoro-substituted organozinc compounds with 1-bromoalkynes has been developed. The reaction is performed under mild conditions affording gem-difluoro-substituted alkynes in good yields. Reaction of organozinc compounds. Proposed

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

• groups in organic synthesis, they are frequently and widely employed in the synthesis of numerous organic products. The generation of a C–X bond, therefore, constitutes an issue of universal interest. Herein, the research advances on the copper-catalyzed and mediated C–X (X = F, Cl, Br, I) bond formation

• catalysis in modern organic synthesis, herein, we would like to highlight the recent progress in the C–H bond halogenation with copper catalysis or mediation. Review Copper-catalyzed/mediated halogenation of the C(sp2)–H bond Halogenation of the arene C(sp2)–H bond In the synthesis of aryl halides employing

• -halosuccinimide, X = Cl or Br). The application of different acids which participated in the in situ formation of acyl hypohalites enabled the selective generation of products 2 and 7 (Scheme 5). Notably, the C–H iodinated product of type 2 was also observed as key intermediate in the copper-catalyzed pyridinyl

Copper-mediated synthesis of N-alkenyl-α,β-unsaturated nitrones and their conversion to tri- and tetrasubstituted pyridines

• Dimitra Kontokosta,
• Daniel S. Mueller,
• Dong-Liang Mo,
• Wiktoria H. Pace,
• Rachel A. Simpson and
• Laura L. Anderson

Beilstein J. Org. Chem. 2015, 11, 2097–2104, doi:10.3762/bjoc.11.226

• products [6][7][8][9][10][11][12][13]. Specifically, we reported that N-arylnitrones 3 can be prepared by a Chan–Lam coupling of 1 and 2 and that these compounds undergo a copper-catalyzed rearrangement to α,β-epoxyimines such as 4 [8]. Reduction of these products in the presence of a Lewis acid gave

• ][38], fragment couplings [39][40][41][42], and transition metal-catalyzed C–H bond functionalization of α,β-unsaturated imines and oximes [43][44][45][46][47][48][49][50]. We were inspired by the copper-catalyzed coupling of protected α,β-unsaturated oximes and alkenylboronic acids developed by

• modularity of the Chan–Lam coupling process, and proceeds through a pathway that is distinct from the Liebeskind copper-catalyzed C–N bond coupling and electrocyclization (Scheme 2). Results and Discussion A Chan–Lam coupling between chalcone oxime 6a and cyclohexenylboronic acid (7a) was initially tested

A new approach to ferrocene derived alkenes via copper-catalyzed olefination

• Vasily M. Muzalevskiy,
• Aleksei V. Shastin,
• Alexandra D. Demidovich,
• Namiq G. Shikhaliev,
• Abel M. Magerramov,
• Victor N. Khrustalev,
• Rustem D. Rakhimov,
• Sergey Z. Vatsadze and
• Valentine G. Nenajdenko

Beilstein J. Org. Chem. 2015, 11, 2072–2078, doi:10.3762/bjoc.11.223

• , 28 Vavilov Street, Moscow 119991, Russia 10.3762/bjoc.11.223 Abstract A new approach to ferrocenyl haloalkenes and bis-alkenes was elaborated. The key procedure involves copper catalyzed olefination of N-unsubstituted hydrazones, obtained from ferrocene-containing carbonyl compounds and hydrazine

• –Fuchs reaction) using a 2–4-fold molar excess of triphenylphosphine [27][28][29][30][31]. Results and Discussion Synthesis of halovinylferrocenes A few years ago we discovered a new reaction for a double carbon–carbon bond formation – the reaction of catalytic olefination. It was shown that the copper

• -catalyzed reaction of unsubstituted hydrazones of aromatic (aliphatic) aldehydes and ketones with a wide range of polyhalogenalkanes leads to the corresponding substituted ethylenes with one or two geminal halogen atoms [32][33][34][35][36]. In the present study, we investigated the possibility of using a

Copper-catalyzed aerobic radical C–C bond cleavage of N–H ketimines

• Ya Lin Tnay,
• Gim Yean Ang and
• Shunsuke Chiba

Beilstein J. Org. Chem. 2015, 11, 1933–1943, doi:10.3762/bjoc.11.209

• Ya Lin Tnay Gim Yean Ang Shunsuke Chiba Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore 10.3762/bjoc.11.209 Abstract We report herein studies on copper-catalyzed aerobic radical C–C bond

• iminyl radicals (Scheme 2). However, the instability of N–H ketimines [50] limits their use as starting materials. Recently, we have studied the chemical reactivity of N–H ketimines towards copper-catalyzed aerobic reaction conditions [51][52][53]. In these studies, we employed the nucleophilic addition

• found to undergo copper-catalyzed aerobic aromatic C–H amination (Scheme 3a) [52] or 1,4-aminooxygenation (spirocyclization) (Scheme 3b) [51], affording phenanthridine derivatives and azaspirocyclohexadienones, respectively, depending on the helical sense of the biaryl axis. Herein we report

Fates of imine intermediates in radical cyclizations of N-sulfonylindoles and ene-sulfonamides

• Hanmo Zhang,
• E. Ben Hay,
• Stephen J. Geib and
• Dennis P. Curran

Beilstein J. Org. Chem. 2015, 11, 1649–1655, doi:10.3762/bjoc.11.181

• alkaloid aspidophytine published in 2008 [14]. In 2005, Stevens and coworkers reported that treatment of trichloroacetamide-substituted N-sulfonylindole 3 under conditions for copper-catalyzed atom transfer cyclization provided chlorine transfer product 4 with the N-sulfonyl group intact (Scheme 1) [15

Deproto-metallation of N-arylated pyrroles and indoles using a mixed lithium–zinc base and regioselectivity-computed CH acidity relationship

• Mohamed Yacine Ameur Messaoud,
• Ghenia Bentabed-Ababsa,
• Madani Hedidi,
• Aïcha Derdour,
• Floris Chevallier,
• Yury S. Halauko,
• Oleg A. Ivashkevich,
• Vadim E. Matulis,
• Laurent Picot,
• Valérie Thiéry,
• Thierry Roisnel,
• Vincent Dorcet and
• Florence Mongin

Beilstein J. Org. Chem. 2015, 11, 1475–1485, doi:10.3762/bjoc.11.160

• obtained together with recovered starting material. In order to test the functionalization of the above synthesized aryl iodides through a subsequent transition-metal-catalyzed coupling reaction we subjected three of them to a copper-catalyzed N-arylation reaction. Thus, the iodides 3b, 3d and 4d were

Synthesis of alpha-tetrasubstituted triazoles by copper-catalyzed silyl deprotection/azide cycloaddition

• Zachary L. Palchak,
• Paula T. Nguyen and
• Catharine H. Larsen

Beilstein J. Org. Chem. 2015, 11, 1425–1433, doi:10.3762/bjoc.11.154

• stoichiometric amounts of metal. A recent cyclohexanone–amine–silylacetylene coupling forms silyl-protected tetrasubstituted propargylamines in a single copper-catalyzed step. The development of the tandem silyl deprotection–triazole formation reported herein offers rapid access to alpha-tetrasubstituted

• ; copper catalysis; multicomponent reactions; tetrasubstituted carbon; triazole; Introduction 1,2,3-Triazoles demonstrate wide spread application in biological systems and drug development [1][2][3][4][5][6][7][8][9][10][11][12]. Copper-catalyzed azide–alkyne cycloadditions (CuAAC) regioselectively

• Scheme 1 would streamline the synthesis of alpha-tetrasubstituted triazoles 6. In the first step, our solvent-free copper-catalyzed three-component coupling of cyclohexanone (1), amines 2, and alkynes 3 provides high yields of silyl-protected propargylic amines 4 [24][25]. Trimethylsilyl (TMS) acetylene

Selected synthetic strategies to cyclophanes

• Sambasivarao Kotha,
• Mukesh E. Shirbhate and
• Gopalkrushna T. Waghule

Beilstein J. Org. Chem. 2015, 11, 1274–1331, doi:10.3762/bjoc.11.142

• provided acrylate 226, which was subjected to enantioselective copper-catalyzed conjugate addition with a methyl Grignard reagent involving (R)-tol-BINAP ligand to generate ester 227 in good yield and high enantiopurity. This intermediate was then converted to the key metathesis precursor involving a three

• ] have reported the synthesis of a glycotriazolophane 309 (carbohydrate–triazole–cyclophane hybrid) from a sugar amino acid via a copper-catalyzed azide-alkyne cycloaddition sequence. An aminosugar acid was identified as a useful building block to generate cyclophanes. Thus, the treatment of 304 with

Intermolecular addition reactions of N-alkyl-N-chlorosulfonamides to unsaturated compounds

• Gerold Heuger and
• Richard Göttlich

Beilstein J. Org. Chem. 2015, 11, 1226–1234, doi:10.3762/bjoc.11.136

• and polar pathways as competing mechanisms and has developed a nice copper-catalyzed oxidative amidation of alkenes whilst Muñiz [27] in a recent publication proposes a polar sulfonamido-chlorination mechanism of alkenes. Similar, intramolecular and intermolecular additions of N-chlorosulfonamides and

An intramolecular C–N cross-coupling of β-enaminones: a simple and efficient way to precursors of some alkaloids of Galipea officinalis

• Hana Doušová,
• Radim Horák,
• Zdeňka Růžičková and
• Petr Šimůnek

Beilstein J. Org. Chem. 2015, 11, 884–892, doi:10.3762/bjoc.11.99

• attempt to reduce the amount of catalyst, however, only led to a decrease in the conversion (Table 2, entry 10). The copper-catalyzed protocol was quite unsuccessful (Table 2, entry 11). Generally, chloro derivatives (and especially non-activated ones) remain challenging substrates for copper catalysis

Tuning of tetrathiafulvalene properties: versatile synthesis of N-arylated monopyrrolotetrathiafulvalenes via Ullmann-type coupling reactions

• Vladimir A. Azov,
• Diana Janott,
• Dirk Schlüter and
• Matthias Zeller

Beilstein J. Org. Chem. 2015, 11, 860–868, doi:10.3762/bjoc.11.96

• different analytical methods and X-ray crystallography. Experimental Copper-catalyzed N-arylation reaction of monopyrrolo-tetrathiafulvalenes, general procedure. The reaction was performed in a similar manner as described before [22]. A heavy walled Schlenk tube with a wide bore Teflon screw stopcock was