Mechanisms for radical reactions initiating from N-hydroxyphthalimide esters

• Carlos R. Azpilcueta-Nicolas and
• Jean-Philip Lumb

Beilstein J. Org. Chem. 2024, 20, 346–378, doi:10.3762/bjoc.20.35

• reported in recent years, including decarboxylative alkynylations [76][77][78] and the C(sp3)–H alkylation of α-amino acids [79]. The ability of NHPI esters to act as dual reagents was also investigated by Glorius and co-workers in the context of a photoinduced Pd-catalyzed aminoalkylation of 1,4-dienes

Cobalt- and rhodium-catalyzed carboxylation using carbon dioxide as the C1 source

• Tetsuaki Fujihara and
• Yasushi Tsuji

Beilstein J. Org. Chem. 2018, 14, 2435–2460, doi:10.3762/bjoc.14.221

• acid derivatives. Diene 14a was converted into the corresponding carboxylic acid 15a in good yield. In addition, 1,4-dienes having cyclohexenyl and geminal diphenyl substituents (14b and 14c) produced their corresponding linear carboxylic acids 15b and 15c in 78% and 57% yields, respectively. Substrate

Cobalt-catalyzed nucleophilic addition of the allylic C(sp³)–H bond of simple alkenes to ketones

• Tsuyoshi Mita,
• Masashi Uchiyama,
• Kenichi Michigami and
• Yoshihiro Sato

Beilstein J. Org. Chem. 2018, 14, 2012–2017, doi:10.3762/bjoc.14.176

• to the case of nucleophilic η1-allylpalladium species [31][32][33][34][35][36][37][38][39]), whereas the cobalt atom preferred to reside at the internal position when allylarenes and 1,4-dienes were employed in our previous studies [28][29]. Subsequently, reductive elimination of methane from III

Chiral cyclopentadienylruthenium sulfoxide catalysts for asymmetric redox bicycloisomerization

• Barry M. Trost,
• Michael C. Ryan and
• Meera Rao

Beilstein J. Org. Chem. 2016, 12, 1136–1152, doi:10.3762/bjoc.12.110

• (MeCN)3PF6-catalyzed variant of the same reaction that proceeds even at room temperature [10]. The ruthenium process differs from the initially-discovered palladium reaction in that it produces cyclic 1,4-dienes exclusively; no olefin isomerization is detected (Scheme 1, path b). Moreover, ruthenium can

• simple 1,6-enynes displayed a broader scope than Mikami’s palladium system, although none of the examples contained a quaternary stereocenter [25]. Asymmetric enyne cycloisomerization reactions can be extended beyond the construction of 1,4-dienes, depending on the transition metal used and the adjacent

Electrochemical selenium- and iodonium-initiated cyclisation of hydroxy-functionalised 1,4-dienes

• Philipp Röse,
• Steffen Emge,
• Jun-ichi Yoshida and
• Gerhard Hilt

Beilstein J. Org. Chem. 2015, 11, 174–183, doi:10.3762/bjoc.11.18

• 10.3762/bjoc.11.18 Abstract The cobalt(I)-catalysed 1,4-hydrovinylation reaction of allyloxytrimethylsilane and allyl alcohol with substituted 1,3-dienes leads to hydroxy-functionalised 1,4-dienes in excellent regio- and diastereoselective fashion. Those 1,4-dienols can be converted into tetrahydrofuran

• and pyran derivatives under indirect electrochemical conditions generating selenium or iodonium cations. The reactions proceed in good yields and regioselectivities for the formation of single diastereomers. Keywords: cyclic ethers; cyclisation; 1,4-dienes; electrochemistry; iodonium; selenium

• ; Introduction The reaction of terminal alkenes with 1,3-dienes under cobalt catalysis results in 1,4-dienes in a 1,4-hydrovinylation reaction. Besides cobalt, also other transition metals were described to undergo such transformations [1][2][3][4]. However, only for the cobalt-catalysed reactions a regiodiverse

Synthesis of five- and six-membered cyclic organic peroxides: Key transformations into peroxide ring-retaining products

• Alexander O. Terent'ev,
• Dmitry A. Borisov,
• Vera A. Vil’ and
• Valery M. Dembitsky

Beilstein J. Org. Chem. 2014, 10, 34–114, doi:10.3762/bjoc.10.6

• reaction products were separated by column chromatography. 1-Hydroxy-1-phenylpentan-3-one (42) was isolated as a by-product in 16% yield [248]. The peroxidation of 1,4-dienes 43a,b with the Co(modp)2/Et3SiH/O2 system according to a similar reaction scheme gave dioxolanes 44a,b. Acetophenone (45) was

• proceeds through a formation of an enol-containing complex with a metal ion (Scheme 57, Table 14). 3.3. Oxidation of 1,5-dienes in the presence of thiols The co-oxidation of 1,4-dienes and thiols (thiol–olefin co-oxygenation, TOCO reaction) was described for the first time by Beckwith and Wagner as a

Micro-flow synthesis and structural analysis of sterically crowded diimine ligands with five aryl rings

• Shinichiro Fuse,
• Nobutake Tanabe,
• Akio Tannna,
• Yohei Konishi and
• Takashi Takahashi

Beilstein J. Org. Chem. 2013, 9, 2336–2343, doi:10.3762/bjoc.9.268

• ligand framework influences the reactivity of the metal center. That is why sterically crowded and neutral-chelating diimine ligands have garnered a great deal of attention [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17]. In recent years, N-aryl 1,3,5-triazapenta-1,4-dienes 1 and 2 have been

• homopolymerization nor copolymerization of ethylene with polar monomers by using the catalysts derived from N-aryl-1,3,5-triazapenta-1,4-dienes 1–3 have been reported [18][19]. Thus, we tested the polymerization activity of the catalyst 12 in the copolymerization of ethylene with 5-norbornen-2-ol (NBO) and ethyl

• . The reaction mixture was concentrated in vacuo. The residue was used for the next reaction without further purification. General procedure for micro-flow synthesis of 1,2,3,4,5-pentaaryl-1,3,5-triazapenta-1,4-dienes 3b and 3c: A T-shape mixer and reaction tube were immersed in a water bath (20 °C

A reductive coupling strategy towards ripostatin A

• Kristin D. Schleicher and
• Timothy F. Jamison

Beilstein J. Org. Chem. 2013, 9, 1533–1550, doi:10.3762/bjoc.9.175

• the double 1,4-diene (Figure 2). Notwithstanding the successful syntheses of ripostatins, preparation of configurationally defined skipped polyenes (1,4-dienes and higher homologues) remains a significant challenge in organic chemistry. The doubly allylic protons found in these structures may be

• sensitive to strong base as well as hydrogen abstraction [10][11]. While classical methods for the preparation of 1,4-dienes include partial reduction of alkynes and carbonyl olefination, a variety of transition-metal-mediated processes have been developed for the synthesis of skipped dienes of varied

• has long been known that cis-disubstituted vinylcyclopropanes can undergo 1,5-hydrogen migration under thermal conditions to deliver acyclic 1,4-dienes [22]. In this reaction manifold, the new “acceptor-derived” double bond is formed via an endo transition state, leading to a cis olefinic

Asymmetric Au-catalyzed cycloisomerization of 1,6-enynes: An entry to bicyclo[4.1.0]heptene

• Alexandre Pradal,
• Chung-Meng Chao,
• Patrick Y. Toullec and
• Véronique Michelet

Beilstein J. Org. Chem. 2011, 7, 1021–1029, doi:10.3762/bjoc.7.116

• process, as the cyclic alkene 3e was isolated in 61% yield (Table 2, entry 4). In the case of non-substituted enyne 1b (Table 2, entry 5), the bicyclic alkenyl derivative 3b was isolated in low yield and ee: The synthesis of 3b was accompanied by the formation of known 1,3- and 1,4-dienes (5% and 10