Hypervalent organoiodine compounds: from reagents to valuable building blocks in synthesis

• Gwendal Grelier,
• Benjamin Darses and
• Philippe Dauban

Beilstein J. Org. Chem. 2018, 14, 1508–1528, doi:10.3762/bjoc.14.128

• reaction has been later found to be mediated by copper(I) cyanide starting from p-methoxystyrene [36]. However, under these conditions, other styrene derivatives bearing a phenyl, a tert-butyl, or an electron-withdrawing substituent have been shown to afford products resulting from a

• –I motif (Scheme 22) [62]. Hence aryl- and alkyl-substituted terminal alkynes can be coupled via a Sonogashira reaction when PPh3 is used as ligand, while the use of diphenylphosphinoferrocenyl ligand (dppf) allows the Heck-type coupling of acrylates, vinyl ketones and electron-poor styrene

• derivatives. This relayed strategy can therefore be applied to non-symmetrical cyclic diaryliodonium species, thereby affording a library of functionalized benzoxazoles 58 with complete regiocontrol. The group of Zhang has developed a one-pot procedure for the sequential difunctionalization of cyclic diaryl

Nanoreactors for green catalysis

• M. Teresa De Martino,
• Loai K. E. A. Abdelmohsen,
• Floris P. J. T. Rutjes and
• Jan C. M. van Hest

Beilstein J. Org. Chem. 2018, 14, 716–733, doi:10.3762/bjoc.14.61

• -proline 4b-catalyzed reactionsa: Asymmetric cyclopropanation reaction of styrene derivatives and ethyl diazoacetatea. Acknowledgements The authors acknowledge support from Horizon 2020 FET-Open program 737266 - ONE-FLOW; with regard to the graphical abstract we acknowledge Dennis Vriezema and Pille et al

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

• 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

• and were able to couple a series of electron-rich and electron-poor styrene derivatives with aromatic and also long-chain aliphatic thiols to the respective sulfoxides, after aerobic oxidation (Scheme 15a). They describe a photocatalyzed thiol–ene reaction mechanism, where the sulfide-adduct is

• Eosin Y radical anion. Subsequently, the sulfur-centred radical adds to styrene and forms the 1,3-oxathiolane-2-thione under aerobic conditions. The catalytic cycle is closed by aerobic oxidation of Eosin Y radical anion. Various styrene derivatives are efficiently converted into the corresponding

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

• introduction of the CF3 moiety and a Cl atom onto alkenes or alkynes. Kamigata’s group was the first to report such type of transformation in 1989 [23][24]. In the presence of RuCl2(PPh3)2 at 120 °C, a variety of styrene derivatives as well as cyclic and acyclic alkenes were converted into their

• chlorotrifluoromethylated analogues (Scheme 16). Generally, the reaction proceeded particularly well with terminal and internal alkenes carrying an electron-withdrawing group. On the contrary, styrene derivatives bearing an electron-donating group provided less satisfying yields. Such results can be explained by the

• were obtained for styrene derivatives, although with a subsequent dehydrochlorination step. If the nature of the substrate undoubtedly played an important role in the reaction process, it was also the case of the catalyst. Indeed, the use of other usual photocatalysts such as [Ru(bpy)3]Cl2, [Ir(ppy)2

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

• to a wide range of alkenes featuring various functional groups. Further reduction of the N–O bond by Mo(CO)6 gave the corresponding alcohols. A protocol free of peroxide initiator was developed by Yang, Vicic and co-workers using a manganese salt and O2 from air [35]. Styrene derivatives were

• concentration, obtained by increasing the amount of copper catalyst, was beneficial to the chemoselectivity. Both styrene derivatives and terminal unactivated alkenes were suitable substrates in this transformation but not internal alkenes [55]. Csp2–CF3 bond-forming reactions Direct trifluoromethylation of

Palladium-catalyzed Heck-type reaction of secondary trifluoromethylated alkyl bromides

• Tao Fan,
• Wei-Dong Meng and
• Xingang Zhang

Beilstein J. Org. Chem. 2017, 13, 2610–2616, doi:10.3762/bjoc.13.258

• (Table 1, entry 14). With the optimized reaction conditions in hand, a variety of alkenes were examined. As shown in Scheme 1, reactions of 2a with a series of styrene derivatives 1 proceeded smoothly and provided 3 in moderate to excellent yields (Scheme 1). Generally, substrates bearing electron

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

• the amine 5e can be readily cleaved for the construction of a secondary amine. Finally, the scope of olefins for the transformation was examined including both aryl and alkyl olefins (Table 2). First, styrene derivatives bearing a variety of substitutions on the aryl ring, including both electron

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

• alkenes under copper(I) catalysis. In reactions of styrene derivatives with terminal double bonds the addition products were obtained in excellent yield and high regioselectivity. Lower yields are obtained in addition reactions to non-aromatic alkenes. The reaction most likely proceeds via a redox

• in a distinct lower yield (Scheme 3). In a next step we added chloroamide 2a to a variety of styrene derivatives (Table 2). Whilst the addition proceeds well with electron-poor styrenes such as 4-nitro and 4-fluorostyrene, an electron rich substrate with a methoxy substituent (Table 2, entry 4) leads

• to a complex mixture of products. Most likely the electron-rich aromatic ring is oxidized under these conditions, leading to a variety of products which could not be separated. With styrene derivatives giving high yields of addition products, we next turned our attention to the less reactive non

Photocatalytic nucleophilic addition of alcohols to styrenes in Markovnikov and anti-Markovnikov orientation

• Martin Weiser,
• Sergej Hermann,
• Alexander Penner and
• Hans-Achim Wagenknecht

Beilstein J. Org. Chem. 2015, 11, 568–575, doi:10.3762/bjoc.11.62

• -Markovnikov-type addition of cyanide to styrene [18]. Recently, we showed by a library of different chromophores that 1-(N,N-dimethylamino)pyrene (Py) can be applied as photocatalyst for the nucleophilic addition of methanol to styrene derivatives into the Markovnikov orientation [19]. Most recently, Nicewicz

• of the two different routes (to the Markovnikov or anti-Markovnikov addition products of styrene derivatives) results from the two types of photoinduced charge transfer initiated by the photoexcited catalyst (Scheme 1). If an electron-poor chromophore is applied, the first step that follows

• to either the Markovnikov- or anti-Markovnikov-type nucleophilic alcohol addition to styrene derivatives was accomplished by Py and PDI as photoredox catalysts. The regioselectivity was controlled by the type of photoinduced charge transfer that was initiated by the photoexcited catalyst. For the

Superoxide chemistry revisited: synthesis of tetrachloro-substituted methylenenortricyclenes

• Basavaraj M. Budanur and
• Faiz Ahmed Khan

Beilstein J. Org. Chem. 2014, 10, 2531–2538, doi:10.3762/bjoc.10.264

• the series of DA adducts 3/4 from pentachloro-5-methylcyclopentadiene 1 and corresponding dienophiles 2 [38][39][40] by heating at 120–130 °C in a sealed tube. Styrene derivatives containing groups like methoxy, alkyl, naphthyl, and biphenyl (Table 1, entries 1–4, 6–9 ), methyl vinyl ketone (Table 1

Synthesis of chiral N-phosphoryl aziridines through enantioselective aziridination of alkenes with phosphoryl azide via Co(II)-based metalloradical catalysis

• Jingran Tao,
• Li-Mei Jin and
• X. Peter Zhang

Beilstein J. Org. Chem. 2014, 10, 1282–1289, doi:10.3762/bjoc.10.129

• reaction conditions, we then investigated the scope and limitation of the [Co(P6)]/TcepN3-based catalytic system for asymmetric olefin aziridination. The Co(II)-catalyzed asymmetric aziridination was shown to be effective for a variety of styrene derivatives with varied electronic and steric properties

• (Table 2). Similar to styrene, the styrene derivatives with electron-donating groups, such as the para-methylated styrene 1b could be effectively aziridinated to afford the corresponding N-phosphoryl aziridine in a high yield with good enantioselectivity (Table 2, entries 1 and 2). In addition to the

Anodic coupling of carboxylic acids to electron-rich double bonds: A surprising non-Kolbe pathway to lactones

• Robert J. Perkins,
• Hai-Chao Xu,
• John M. Campbell and
• Kevin D. Moeller

Beilstein J. Org. Chem. 2013, 9, 1630–1636, doi:10.3762/bjoc.9.186

• on resonance stabilization of the resulting cation. Anodic coupling of ketene dithioacetals and carboxylic acids. Extension to other electron-rich olefins. Extension to styrene derivatives. Supporting Information Supporting Information File 132: Procedures for electrolysis and cyclic voltammetry

Stability of SG1 nitroxide towards unprotected sugar and lithium salts: a preamble to cellulose modification by nitroxide-mediated graft polymerization

• Guillaume Moreira,
• Laurence Charles,
• Mohamed Major,
• Florence Vacandio,
• Yohann Guillaneuf,
• Catherine Lefay and
• Didier Gigmes

Beilstein J. Org. Chem. 2013, 9, 1589–1600, doi:10.3762/bjoc.9.181

• of styrene derivatives. Another important property of TEMPO is that it is reduced by reducing sugars such as glucose [18]. The consumption of nitroxides by reducing agents such as a sugar or a polysaccharide is of prime importance when aiming at the synthesis of glycopolymers or the graft

Inter- and intramolecular enantioselective carbolithiation reactions

• Asier Gómez-SanJuan,
• Nuria Sotomayor and
• Esther Lete

Beilstein J. Org. Chem. 2013, 9, 313–322, doi:10.3762/bjoc.9.36

• in different ways, to avoid this polymerization (Scheme 1). The first examples of intermolecular enantioselective carbolithiations of styrene derivatives were reported by Normant and Marek [9], taking advantage of the complex-induced proximity effect (CIPE). Thus, the addition of primary and

• fully developed. On the other hand, the high reactivity of the organolithiums requires the use of stoichiometric amounts of the chiral ligand. Intermolecular carbolithiation. Carbolithiation of cinnamyl and dienyl derivatives. Carbolithiation of cinnamyl alcohol. Carbolithiation of styrene derivatives

• alcohol (9) with the complex of butyllithium/diamine L2 in cumene at 0 °C, obtaining alcohol (R)-11 in 71% yield with 71% ee (Scheme 3). This is essentially opposite to the enantioselectivity obtained previously with (−)-sparteine L1 (82% yield, 83% ee in favor of (S)-11) [10]. Substituted styrene

Recent advances in transition-metal-catalyzed intermolecular carbomagnesiation and carbozincation

• Kei Murakami and
• Hideki Yorimitsu

Beilstein J. Org. Chem. 2013, 9, 278–302, doi:10.3762/bjoc.9.34

•  37). Although the cobalt-catalyzed allylzincation reactions of dialkylacetylenes resulted in low yield, the reactions of arylacetylenes provided various tri- or tetrasubstituted styrene derivatives (Scheme 38) [119][120]. Kambe reported a rare example of silver catalysis for carbomagnesiation

Highly substituted benzannulated cyclooctanol derivatives by samarium diiodide-induced cyclizations

• Jakub Saadi,
• Irene Brüdgam and
• Hans-Ulrich Reissig

Beilstein J. Org. Chem. 2010, 6, 1229–1245, doi:10.3762/bjoc.6.141

• -trig cyclizations to cycloheptanol derivatives have been observed. In examples with high steric hindrance the ketyl–aryl coupling can be a competing process. Keywords: cyclooctanes; ketones; ketyls; medium-sized rings; samarium diiodide; single electron transfer; styrene derivatives; radicals