Cobalt-catalyzed directed C–H alkenylation of pivalophenone N–H imine with alkenyl phosphates

• Wengang Xu and
• Naohiko Yoshikai

Beilstein J. Org. Chem. 2018, 14, 709–715, doi:10.3762/bjoc.14.60

• groups into the ortho position of functionalized arenes has attracted significant attention because of the synthetic versatility of alkenyl groups. The C–H alkenylation has been achieved most extensively by way of the dehydrogenative Heck-type reaction of olefins [7][8][9]. Meanwhile, the hydroarylation

Liquid-assisted grinding and ion pairing regulates percentage conversion and diastereoselectivity of the Wittig reaction under mechanochemical conditions

• Kendra Leahy Denlinger,
• Lianna Ortiz-Trankina,
• Preston Carr,
• Kingsley Benson,
• Daniel C. Waddell and
• James Mack

Beilstein J. Org. Chem. 2018, 14, 688–696, doi:10.3762/bjoc.14.57

• of the Wittig reaction under mechanochemical conditions [17][18]. The Wittig reaction is one of the most useful reactions for the synthesis of olefins [19][20][21][22][23]. Aside from its synthetic utility, its unique reaction mechanism (shown in Figure 1) and inherent diastereoselectivity has led to

Electrochemical Corey–Winter reaction. Reduction of thiocarbonates in aqueous methanol media and application to the synthesis of a naturally occurring α-pyrone

• Ernesto Emmanuel López-López,
• José Alvano Pérez-Bautista,
• Fernando Sartillo-Piscil and
• Bernardo A. Frontana-Uribe

Beilstein J. Org. Chem. 2018, 14, 547–552, doi:10.3762/bjoc.14.41

• stereospecific preparation of olefins in large scale [3]. Furthermore, the introduction of 1,3-dimethyl-2-phenyl-1,3,2-diazaphospholidine (D, Corey–Hopkins reagent) as the reductive reagent, has resulted in the development of a milder Corey–Winter protocol, which can be now carried out near to room temperature

• formed by β-fragmentation of radical anion F, is maximum when is locked in an antiperiplanar conformation (Scheme 4). Therefore, this electrochemical reaction represents a promising way to produce trans-olefins from their respective thiocarbonates, overcoming thus the toxicity and safety issues of the

The selective electrochemical fluorination of S-alkyl benzothioate and its derivatives

• Shunsuke Kuribayashi,
• Tomoyuki Kurioka,
• Shinsuke Inagi,
• Ho-Jung Lu,
• Biing-Jiun Uang and
• Toshio Fuchigami

Beilstein J. Org. Chem. 2018, 14, 389–396, doi:10.3762/bjoc.14.27

• , Rozhkov and Laurent reported an electrochemical partial fluorination of naphthalene and olefins about 30 years ago [5][6]. However, at that time, there has been no report on the anodic fluorination of heteroatom-containing compounds. At almost the same time, we found that the anodic α-methoxylation of

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

• 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

Photocatalytic formation of carbon–sulfur bonds

• Alexander Wimmer and
• Burkhard König

Beilstein J. Org. Chem. 2018, 14, 54–83, doi:10.3762/bjoc.14.4

• preparation of sulfides. Non-photocatalytic procedures apply the so-called radical thiol–ene or radical thiol–yne reactions for efficient cross-coupling of thiols with olefins [24][29][30]. In 2013, Yoon and co-workers developed a photoredox-catalyzed version of the radical thiol–ene reaction (Scheme 2) [31

• visible-light irradiation of the photoorganocatalyst. Aliphatic and aromatic thiols reacted with aliphatic olefins and styrene derivatives in high yields. Recently, additional procedures for the photoredox-catalyzed radical thiol–ene and thiol–yne reaction were reported. Xia and co-workers describe a

• olefins. For their reaction, they applied p-toluene selenosulfonate and found that especially electron-rich olefins worked well under their conditions. The difunctionalized products (β-selenosulfones) were obtained in high yields from a series of alkyl vinyl ethers. The reaction proceeds via an oxidative

The photodecarboxylative addition of carboxylates to phthalimides as a key-step in the synthesis of biologically active 3-arylmethylene-2,3-dihydro-1H-isoindolin-1-ones

• Ommid Anamimoghadam,
• Saira Mumtaz,
• Anke Nietsch,
• Gaetano Saya,
• Cherie A. Motti,
• Jun Wang,
• Peter C. Junk,
• Ashfaq Mahmood Qureshi and
• Michael Oelgemöller

Beilstein J. Org. Chem. 2017, 13, 2833–2841, doi:10.3762/bjoc.13.275

• . Sulfuric acid-catalyzed dehydrations of the benzylated hydroxyphthalimidines 3a–q in dichloromethane at room temperature resulted in the corresponding olefins 7a–q in good to excellent yields of 66–95% (Scheme 5 and Table 3). The simple reaction protocol enabled parallel operations in a Radleys Carousel 6

CF₃SO₂X (X = Na, Cl) as reagents for trifluoromethylation, trifluoromethylsulfenyl-, -sulfinyl- and -sulfonylation and chlorination. Part 2: Use of CF₃SO₂Cl

• Hélène Chachignon,
• Hélène Guyon and
• Dominique Cahard

Beilstein J. Org. Chem. 2017, 13, 2800–2818, doi:10.3762/bjoc.13.273

• , regenerating the trifluoromethyl radical in the process, was also considered. Intermediate 2 was ultimately converted into the final product after liberating an acetyl cation, which was captured by a chloride anion to give acetyl chloride (Scheme 3). Trifluoromethylation of olefins with cascade reactions: The

• final product increased. Cyclic olefins and dienes proved to be more problematic substrates because they raised stereoselectivity issues and afforded poor yields. As for the mechanism, the reaction followed a similar pathway as the one proposed by the same group for the trifluoromethylation of silyl

• (CF3SO2)2Zn, which demonstrated great efficiency in introducing the CF3 moiety on (hetero)aromatic rings [34]. Trifluoromethylation of olefins: In 2005, Vogel and co-workers showed that terminal alkenes could be trifluoromethylated by means of CF3SO2Cl via a palladium-catalysed desulfitative Mizoroki–Heck

CF₃SO₂X (X = Na, Cl) as reagents for trifluoromethylation, trifluoromethylsulfenyl-, -sulfinyl- and -sulfonylation. Part 1: Use of CF₃SO₂Na

• Hélène Guyon,
• Hélène Chachignon and
• Dominique Cahard

Beilstein J. Org. Chem. 2017, 13, 2764–2799, doi:10.3762/bjoc.13.272

• the α-CF3 carbonyl compound 4 (Scheme 3). Unactivated olefins are widely available substrates prone to be transformed into α-trifluoromethyl carbonyl compounds under oxidative trifluoromethylation as first reported by Maiti and co-workers in 2013. The reaction is operationally simple, conducted under

• air at room temperature and presents a predictable reactivity pattern as well as a wide functional group tolerance. The substrate scope was evaluated on 33 styrenes, β-substituted styrenes, heteroaromatic olefins and vinyl cycloalkanes (Scheme 4). The trifluoromethyl radical was generated from

Asymmetric synthesis of propargylamines as amino acid surrogates in peptidomimetics

• Matthias Wünsch,
• David Schröder,
• Tanja Fröhr,
• Lisa Teichmann,
• Sebastian Hedwig,
• Nils Janson,
• Clara Belu,
• Jasmin Simon,
• Shari Heidemeyer,
• Philipp Holtkamp,
• Jens Rudlof,
• Lennard Klemme,
• Alessa Hinzmann,
• Beate Neumann,
• Hans-Georg Stammler and
• Norbert Sewald

Beilstein J. Org. Chem. 2017, 13, 2428–2441, doi:10.3762/bjoc.13.240

• acid function of amino acids can be easily converted into amides or esters (Figure 1), propargylamines have been converted into acids, alcohols [12] or olefins in order to obtain natural products like angustureine and cuspareine [13]. Intramolecular Pauson–Khand reaction [14], Diels–Alder reaction [15

Synthesis of ergostane-type brassinosteroids with modifications in ring A

• Vladimir N. Zhabinskii,
• Darya A. Osiyuk,
• Yuri V. Ermolovich,
• Natalia M. Chaschina,
• Tatsiana S. Dalidovich,
• Miroslav Strnad and
• Vladimir A. Khripach

Beilstein J. Org. Chem. 2017, 13, 2326–2331, doi:10.3762/bjoc.13.229

• mesylation of diol 18 produced dimesylate 19, which was treated with zinc dust and sodium iodide in refluxing DMF (Tipson–Cohen reaction [16]) to give, after deacetylation, B-lactone olefin 21 in 96% yield. 2α,3α- and 2β,3β-epoxides of type 4 and 5 Olefins of type 3 are evident intermediates for the

Conjugated nitrosoalkenes as Michael acceptors in carbon–carbon bond forming reactions: a review and perspective

• Yaroslav D. Boyko,
• Valentin S. Dorokhov,
• Alexey Yu. Sukhorukov and
• Sema L. Ioffe

Beilstein J. Org. Chem. 2017, 13, 2214–2234, doi:10.3762/bjoc.13.220

• . Considering the fact that cyclic chloroketones are prepared by chloronitrosylation of cyclic olefins, the overall process is a highly straightforward strategy for the conversion of alkenes to bioactive 5-aminoisoxazoles [80]. Our group employed N,N-bis(silyloxy)enamines 3 as sources of nitrosoalkenes in

Synthesis of 2-aminosuberic acid derivatives as components of some histone deacetylase inhibiting cyclic tetrapeptides

• Shital Kumar Chattopadhyay,
• Suman Sil and
• Jyoti Prasad Mukherjee

Beilstein J. Org. Chem. 2017, 13, 2153–2156, doi:10.3762/bjoc.13.214

• of 27% over seven high yielding simple steps. Having access to the building block 11, we focused on its conversion to the targeted Asu derivatives through cross metathesis (CM) [20] with conjugated olefins 13a–d (Scheme 2). In recent years, the cross-metathesis reaction has emerged as a valuable tool

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

• –Hillman reaction The Morita–Baylis–Hillman reaction (MBH) employs olefins, tertiary amine catalysts and electrophile aldehydes to produce multifunctional products. Mack et al., found a significant enhancement in the rate of a Morita–Baylis–Hillman (MBH) reaction under ball milling conditions (Scheme 5

• ]. Advantageously this methodology was applicable for both solid and liquid olefins. Mechanochemical C–H functionalization Transition-metal-catalyzed activation and functionalization of inert C–H bonds of organic molecules provides a broad avenue in the synthesis of wide range of compounds. In 2015, Bolm and co

Pd(OAc)₂/Ph₃P-catalyzed dimerization of isoprene and synthesis of monoterpenic heterocycles

• Dominik Kellner,
• Maximilian Weger,
• Andrea Gini and
• Olga García Mancheño

Beilstein J. Org. Chem. 2017, 13, 1807–1815, doi:10.3762/bjoc.13.175

• - and N-heterocycles The different dimers of isoprene can be transformed into a large number of derivatives such as terpene-alcohols or ethers [38]. Moreover, some isoprene dimers have been submitted to Diels–Alder reactions with olefins such as maleic acid anhydride or methacrolein to form products

An effective Pd nanocatalyst in aqueous media: stilbene synthesis by Mizoroki–Heck coupling reaction under microwave irradiation

• Carolina S. García,
• Paula M. Uberman and
• Sandra E. Martín

Beilstein J. Org. Chem. 2017, 13, 1717–1727, doi:10.3762/bjoc.13.166

• Mizoroki–Heck coupling reactions under microwave irradiation (MW) were carried out with a colloidal Pd nanocatalyst stabilized with poly(N-vinylpyrrolidone) (PVP). Many stilbenes and novel heterostilbenes were achieved in good to excellent yields starting from aryl bromides and different olefins. The

• is considerable room for improvements of the reported catalytic systems, which may involve high catalyst loadings (>1 mol %), toxic solvents, or limited application scope of iodoarenes and olefins [19]. Along with the increasing awareness about the development of sustainable catalysts, additional

• -catalyzed Mizoroki–Heck coupling, a systematic study of the reaction was carried out with a wide range of substrates and olefins. Based on our previous results [47], and other reported examples of Mizoroki–Heck coupling reactions that use MW irradiation as alternative energy input [26][28][36][49], the

Encaging palladium(0) in layered double hydroxide: A sustainable catalyst for solvent-free and ligand-free Heck reaction in a ball mill

• Wei Shi,
• Jingbo Yu,
• Zhijiang Jiang,
• Qiaoling Shao and
• Weike Su

Beilstein J. Org. Chem. 2017, 13, 1661–1668, doi:10.3762/bjoc.13.160

• ) shows the remarkable activity in Heck reactions with a wide range of aryl bromides and olefins under mild conditions. In these cases, toxic solvents, expensive ligands and inert atmosphere were efficiently avoided. Furthermore, the Pd/MgAl-LDH catalyst can be recycled for at least five times without

The chemistry and biology of mycolactones

• Matthias Gehringer and
• Karl-Heinz Altmann

Beilstein J. Org. Chem. 2017, 13, 1596–1660, doi:10.3762/bjoc.13.159

Mechanochemical borylation of aryldiazonium salts; merging light and ball milling

• José G. Hernández

Beilstein J. Org. Chem. 2017, 13, 1463–1469, doi:10.3762/bjoc.13.144

• the photodimerizations of olefins by manual grinding of the reactants followed by long UV-light exposure [10], or by vortex grinding [11]. However, until now, studies of photocatalyzed mechanochemical reactions involving, for example, metal complexes [12] or organic photocatalysts (PC) [13] has been

Urea–hydrogen peroxide prompted the selective and controlled oxidation of thioglycosides into sulfoxides and sulfones

• Adesh Kumar Singh,
• Varsha Tiwari,
• Kunj Bihari Mishra,
• Surabhi Gupta and
• Jeyakumar Kandasamy

Beilstein J. Org. Chem. 2017, 13, 1139–1144, doi:10.3762/bjoc.13.113

• within 1.5 h. However, corresponding sulfone was obtained in a moderated yield due to instability which undergoes partial amount of decomposition. In general, olefins functional groups are known to undergo epoxidation or dihydroxylation with different oxidizing agents (e.g. m-CPBA, t-BuOOH, oxone, etc

Cycloheximide congeners produced by Streptomyces sp. SC0581 and photoinduced interconversion between (E)- and (Z)-2,3-dehydroanhydrocycloheximides

• Li Yang,
• Ping Wu,
• Jinghua Xue,
• Huitong Tan,
• Zheng Zhang and
• Xiaoyi Wei

Beilstein J. Org. Chem. 2017, 13, 1039–1049, doi:10.3762/bjoc.13.103

• likely a photochemical process as it is known that most Z/E isomerizations of carbon double bonds in conjugated olefins and α,β-enones are facilitated by this process [12][13][14]. However, as all experiments in the present study were carried out either in the dark (fermentation) or under indoor light

Continuous-flow processes for the catalytic partial hydrogenation reaction of alkynes

• Carmen Moreno-Marrodan,
• Francesca Liguori and
• Pierluigi Barbaro

Beilstein J. Org. Chem. 2017, 13, 734–754, doi:10.3762/bjoc.13.73

• ) produces 1-hexene (1a), one of the most commercially important linear α-olefins used in copolymerization processes [116][117]. High density polyethylene (HDPE) and linear low density polyethylene (LLDPE) contain approximately 2–4% and 8–10% of 1a, respectively [118]. 1-Hexene can be produced in ca. 91

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

• protocol is successfully used with various electron-deficient substituted phenyl groups (15b–e) and with heterocycles (15f–h). The double-bond of cyanopyrrolidine 14l is preserved from the hydroboration reaction (15l). Olefins bearing bulky ester, sulfone or amide groups afforded good to excellent yields

Efficient access to β-vinylporphyrin derivatives via palladium cross coupling of β-bromoporphyrins with N-tosylhydrazones

• Vinicius R. Campos,
• Ana T. P. C. Gomes,
• Anna C. Cunha,
• Maria da Graça P. M. S. Neves,
• Vitor F. Ferreira and
• José A. S. Cavaleiro

Beilstein J. Org. Chem. 2017, 13, 195–202, doi:10.3762/bjoc.13.22

• features – stoichiometric organometallic reagents are not required for the coupling reaction and di- and trisubstituted olefins can be prepared with high stereoselectivity. In fact, N-tosylhydrazones used in this methodology can be easily prepared from carbonyl compounds (Scheme 1), as it has been well

Multicomponent synthesis of spiropyrrolidine analogues derived from vinylindole/indazole by a 1,3-dipolar cycloaddition reaction

• Manjunatha Narayanarao,
• Lokesh Koodlur,
• Vijayakumar G. Revanasiddappa,
• Subramanya Gopal and
• Susmita Kamila

Beilstein J. Org. Chem. 2016, 12, 2893–2897, doi:10.3762/bjoc.12.288

• stereospecific cyclic adducts. Keywords: L-proline; ninhydrin; sarcosine; spiropyrrolidine; 5-vinylindazole; 5-vinylindole; Introduction The [3 + 2] cycloaddition between azomethine ylides and olefins/acetylene as dipolarophiles is an important reaction to access a number of novel heterocyclic spiro scaffolds