Iodination of carbohydrate-derived 1,2-oxazines to enantiopure 5-iodo-3,6-dihydro-2H-1,2-oxazines and subsequent palladium-catalyzed cross-coupling reactions

• Michal Medvecký,
• Igor Linder,
• Luise Schefzig,
• Hans-Ulrich Reissig and
• Reinhold Zimmer

Beilstein J. Org. Chem. 2016, 12, 2898–2905, doi:10.3762/bjoc.12.289

• -oxazines bearing the newly installed alkynyl group at C-5 are ideal candidates for efficient subsequent transformations. A very popular and widely applied reaction of terminal alkynes is the copper-catalyzed azide–alkyne cycloaddition, also termed as click reaction, efficiently leading to 1,4-disubstituted

Versatile synthesis of end-reactive polyrotaxanes applicable to fabrication of supramolecular biomaterials

• Atsushi Tamura,
• Asato Tonegawa,
• Yoshinori Arisaka and
• Nobuhiko Yui

Beilstein J. Org. Chem. 2016, 12, 2883–2892, doi:10.3762/bjoc.12.287

• (benzylazide: PRX-Bn-N3, phenylazide: PRX-Ph-N3,) were synthesized for functionalization via click reactions. The PRX-Bn-N3 and PRX-Ph-N3 reacted quickly and efficiently with p-(tert-butyl)phenylacetylene via copper-catalyzed click reactions. Additionally, the terminal azide groups of the PRX-Bn-N3 could be

• (Supporting Information File 1, Figure S2). These results clearly demonstrate the successful synthesis of PRXs with well-defined terminal structures. Reactivity of terminal azide groups in PRXs with alkynes via copper-catalyzed click reaction The reactivity of the terminal azide groups of 4a and 4b with

• alkynes via the copper-catalyzed click reaction was examined. In this experiment, p-(tert-butyl)phenylacetylene was utilized as the model alkyne. One equivalent of p-(tert-butyl)phenylacetylene was allowed to react with the terminal azide groups of the PRXs in the presence of CuSO4 and sodium ascorbate

Identification, synthesis and mass spectrometry of a macrolide from the African reed frog Hyperolius cinnamomeoventris

• Markus Menke,
• Pardha Saradhi Peram,
• Iris Starnberger,
• Walter Hödl,
• Gregory F.M. Jongsma,
• David C. Blackburn,
• Mark-Oliver Rödel,
• Miguel Vences and
• Stefan Schulz

Beilstein J. Org. Chem. 2016, 12, 2731–2738, doi:10.3762/bjoc.12.269

• material. After copper-catalyzed opening of the epoxide with 6-heptenylmagnesium bromide obtained from 7-bromo-1-heptene (14) and Steglich esterification with 5-hexenoic acid (16), RCM using (Z)-selective Grubbs catalyst 12 was used to synthesize macrolide (R)-1 without any isomerization. Comparison of the

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

Synthesis of polyhydroxylated decalins via two consecutive one-pot reactions: 1,4-addition/aldol reaction followed by RCM/syn-dihydroxylation

• Michał Malik and
• Sławomir Jarosz

Beilstein J. Org. Chem. 2016, 12, 2602–2608, doi:10.3762/bjoc.12.255

• Michal Malik Slawomir Jarosz Institute of Organic Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland 10.3762/bjoc.12.255 Abstract Synthesis of novel polyhydroxylated derivatives of decalin is described. The presented methodology consists in a one-pot copper-catalyzed

• possibility of using a copper-catalyzed one-pot 1,4-addition of vinylmagnesium bromide to sugar-derived cyclic α,β-unsaturated ketones (such as 9), followed by an aldol reaction with an optically pure derivative of but-2-enal 10 to obtain a mixture of diastereomeric dienes, such as 11 (Scheme 2). As a result

• of this transformation, three new stereogenic centers are generated. A copper-catalyzed 1,4-addition of organometallic reagents to cyclic α,β-unsaturated ketones, followed by an aldol reaction has been already used in the synthesis of complex natural products [26][27][28][29][30][31][32][33

Et₃B-mediated and palladium-catalyzed direct allylation of β-dicarbonyl compounds with Morita–Baylis–Hillman alcohols

• Ahlem Abidi,
• Yosra Oueslati and
• Farhat Rezgui

Beilstein J. Org. Chem. 2016, 12, 2402–2409, doi:10.3762/bjoc.12.234

• conjugate addition of the β-keto ester carbanion onto the enone moiety (Scheme 2) [50][51]. The structure of the tricyclic compound 6j was elucidated on the basis of X-ray diffraction analysis (Figure 2). In a previous report, Alexakis and co-workers have demonstrated that copper-catalyzed conjugate

Stereo- and regioselectivity of the hetero-Diels–Alder reaction of nitroso derivatives with conjugated dienes

• Lucie Brulíková,
• Aidan Harrison,
• Marvin J. Miller and
• Jan Hlaváč

Beilstein J. Org. Chem. 2016, 12, 1949–1980, doi:10.3762/bjoc.12.184

• Scheme 5). More recently, the method was extended to the mild copper-catalyzed aerobic oxidation of hydroxylamines [48][49][50]. In 2014, the Lykakis group reported the selective oxidation of various arylamines into the corresponding nitrosoarenes through polyoxometalate anions supported on mesoporous

• reagent 58 with cyclohexadiene derivative 154 led to the exclusive formation of proximal isomers 155 in moderate to good yields with ee values ≥95% (Scheme 31). The regioselectivity was opposite of that obtained in the copper-catalyzed reaction. The authors explained this by means of the proposed

Dinuclear thiazolylidene copper complex as highly active catalyst for azid–alkyne cycloadditions

• Anne L. Schöffler,
• Ata Makarem,
• Frank Rominger and
• Bernd F. Straub

Beilstein J. Org. Chem. 2016, 12, 1566–1572, doi:10.3762/bjoc.12.151

• -heterocyclic carbene, linker, sacrificial ligand, and counter ion. Keywords: catalysis; click; copper; CuAAC; N-heterocyclic carbene; thiazole; Introduction The copper-catalyzed azide–alkyne cycloaddition (CuAAC) is one of the most important “click” reactions for the facile covalent linking of two molecules

Selective bromochlorination of a homoallylic alcohol for the total synthesis of (−)-anverene

• Frederick J. Seidl and
• Noah Z. Burns

Beilstein J. Org. Chem. 2016, 12, 1361–1365, doi:10.3762/bjoc.12.129

• success in the copper-catalyzed cross coupling of an analogous dichlorotriflate [9], in our hands 2 failed to engage in productive carbon–carbon bond formation. An alternative retrosynthesis traced 1 back to bromochloroaldehyde 3, which should readily engage in standard olefination reactions. As 3 could

Copper-catalyzed [3 + 2] cycloaddition of (phenylethynyl)di-p-tolylstibane with organic azides

• Mizuki Yamada,
• Mio Matsumura,
• Yuki Uchida,
• Masatoshi Kawahata,
• Yuki Murata,
• Naoki Kakusawa,
• Kentaro Yamaguchi and
• Shuji Yasuike

Beilstein J. Org. Chem. 2016, 12, 1309–1313, doi:10.3762/bjoc.12.123

• clarity. Two independent molecules exist in the asymmetric unit, one of them is shown. Copper-catalyzed [3 + 2] cycloaddition of 1 with organic azides 2. Reaction conditions: 1 (0.5 mmol), 2a (0.5 mmol), Cu cat. (0.025 mmol). Isolated yield are shown. Possible mechanism. Reaction of 3a with HCl, I2 and

Multicomponent reactions: A simple and efficient route to heterocyclic phosphonates

• Mohammad Haji

Beilstein J. Org. Chem. 2016, 12, 1269–1301, doi:10.3762/bjoc.12.121

• multicomponent reactions Transition metals, especially Pd and Cu, are well-known catalysts for multicomponent reactions. Carbopalladation reactions of allenes, alkynes and carbon monoxide are very important processes in multicomponent syntheses. Additionally, copper-catalyzed multicomponent reactions such as

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

• γ-arylpropylpicolinamides were then selectively iodinated at the remote ε-C(sp2)−H position via a rarely precedented PA-directed electrophilic aromatic substitution (SEAr) reaction (Scheme 1, reaction 2) [21][22]. Copper-catalyzed intramolecular C−N cyclization of these ortho-iodinated intermediates

Catalytic asymmetric synthesis of biologically important 3-hydroxyoxindoles: an update

• Bin Yu,
• Hui Xing,
• De-Quan Yu and
• Hong-Min Liu

Beilstein J. Org. Chem. 2016, 12, 1000–1039, doi:10.3762/bjoc.12.98

• increasing attention in the last decades and have been successfully employed in various transformations. In 2014, Cai and co-workers reported a copper-catalyzed asymmetric direct addition of acetonitrile to isatins in the presence of K2CO3 (Scheme 4) [16]. The reactions were conducted in acetonitrile using

The synthesis of functionalized bridged polycycles via C–H bond insertion

• Jiun-Le Shih,
• Po-An Chen and
• Jeremy A. May

Beilstein J. Org. Chem. 2016, 12, 985–999, doi:10.3762/bjoc.12.97

• limitations. Bridged rings from N–H bond insertions. The synthesis of deoxystemodin. A model system for ingenol. Formal synthesis of platensimycin. The formal synthesis of gerryine. Copper-catalyzed bridged-ring synthesis. Factors influencing insertion selectivity. Bridged-lactam formation. The total

Bi- and trinuclear copper(I) complexes of 1,2,3-triazole-tethered NHC ligands: synthesis, structure, and catalytic properties

• Shaojin Gu,
• Jiehao Du,
• Jingjing Huang,
• Huan Xia,
• Ling Yang,
• Weilin Xu and
• Chunxin Lu

Beilstein J. Org. Chem. 2016, 12, 863–873, doi:10.3762/bjoc.12.85

• , 134.68, 133.85, 129.16, 128.98, 128.81, 128.12, 125.04, 124.62, 124.35, 123.79, 110.58, 110.26, 54.49, 51.29, 40.72; Anal. calcd for C69H60Cu3F18N18P3: C, 46.90; H, 3.42; Cu, 10.79; N, 14.27; found: C, 46.35; H, 3.31; N, 13.95. General procedure for the copper-catalyzed CuAAC reaction: Analogously as

Gold-catalyzed direct alkynylation of tryptophan in peptides using TIPS-EBX

• Gergely L. Tolnai,
• Jonathan P. Brand and
• Jerome Waser

Beilstein J. Org. Chem. 2016, 12, 745–749, doi:10.3762/bjoc.12.74

• blocks in synthetic organic chemistry. Recently, they have attracted also strong interest for applications in materials science and chemical biology [1]. One of the most important transformations of alkynes is the copper-catalyzed [3 + 2] cycloaddition with azides, which can be performed under mild

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

• enantioselective versions of these transformations. Copper-catalyzed C–H oxidation In an effort to establish a chemical toolkit to rapidly deliver oxidized drug metabolites, Touré, Sames and co-workers have discovered that piperazines could be oxidized to diketopiperazines as well as ring fragmented products under

• )piperazines by Murai et al. in 1997 [52]. Ta-catalyzed hydroaminoalkylation of piperazines by Schafer et al. in 2013 [55]. Photoredox catalysis for α-C–H functionalization of piperazines by MacMillan et al. in 2011 and 2014 [63][65][66]. Copper-catalyzed aerobic C–H oxidation of piperazines by Touré, Sames

Creating molecular macrocycles for anion recognition

• Amar H. Flood

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

• house is just as satisfying as that of a new molecule and often takes the same amount of time (left: Franck Boston copyright 123RF.com). Timeline of anion-binding macrocycles. Click chemistry’s copper-catalyzed azide–alkyne cycloaddition (CuAAC) forms 1,2,3-triazoles that stabilize anions by CH hydrogen

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

• . Recently, we reported a copper-catalyzed C–C bond formation by substitution of the labile C(4)SMe group in 4H-chromenes or C(3)–OH in isoindolinones with aryl/alkenyl groups by employing the corresponding boronic acids [51][52]. Continuing these efforts, we designed a copper-catalyzed synthesis of a

• ). Structure of 11l was readily confirmed on the basis of 13C NMR and DEPT-135 spectra. We surmise that the initially formed, transmetallated product 18 rearranged to the more stable 18a before it could react with diphenylmethanol (9a, Scheme 4). The scope of the copper-catalyzed coupling reaction of

• diarylmethanols 9b–d with phenylboronic acid (10a) was explored by changing one or both of the aryl rings in the diarylmethanol (Table 3) [62]. The copper-catalyzed reaction of phenyl(pyren-1-yl)methanol (9b) with phenylboronic acid (10a) was very facile and the product triarylmethane 11n was obtained in 72

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

• with molecular oxygen can be used to perform benzylic oxidations [20]. The aerobic copper-catalyzed α-oxygenation of 2-arylthioacetamides was reported by Moghaddam [21]. In this transformation CuCl2 and K2CO3 in DMF were used to produce α-ketoarylthioacetamides. The coupling of 2-arylacetaldehydes with

• -benzylpyridines (1).a Iron and copper-catalyzed aerobic oxidation of pyridine-substituted 2-benzylpyridines (3).a The influence of the purification method on the amount of Fe impurities in papaveraldine (15) after oxidation. An extended solvent screening for the base metal-catalyzed aerobic oxidation reaction.a

Copper-catalyzed intermolecular oxyamination of olefins using carboxylic acids and O-benzoylhydroxylamines

• Brett N. Hemric and
• Qiu Wang

Beilstein J. Org. Chem. 2016, 12, 22–28, doi:10.3762/bjoc.12.4

• Brett N. Hemric Qiu Wang Department of Chemistry, Duke University, Durham, NC, USA 10.3762/bjoc.12.4 Abstract This paper reports a novel approach for the direct and facile synthesis of 1,2-oxyamino moieties via an intermolecular copper-catalyzed oxyamination of olefins. This strategy utilizes O

• oxygen sources, such as TEMPO and acetate. Herein, we envisioned that a copper-catalyzed intermolecular olefin oxyamination could be achieved using O-acylhydroxylamines as an electrophilic amino precursor [35][36][37][38][39] and carboxylic acids as a nucleophilic oxygen source (Scheme 1E). The proposed

• transformation, integrating an electrophilic amination with a nucleophilic oxygenation, builds upon our recent development in copper-catalyzed olefin difunctionalization, such as copper-catalyzed diamination [40] and amino lactonization [34]. This strategy overcomes common issues of chemo- and regioselectivity

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