Synthetic approaches to bowl-shaped π-conjugated sumanene and its congeners

• Shakeel Alvi and
• Rashid Ali

Beilstein J. Org. Chem. 2020, 16, 2212–2259, doi:10.3762/bjoc.16.186

• energy level and hence may be gifted to achieve a large open-circuit voltage. To this context, Amaya et al. has developed a novel bissumanenylidene 47 starting from the parent sumanene (2) first by converting it into the monoketosumanene followed by McMurry coupling reaction (Scheme 9). Although, they

• been noticed from the literature that the construction of these types of sterically hindered tetrasubstituted alkenes is really difficult through McMurry coupling reaction or by other means (Scheme 14). 2.2 Functionalization at benzene ring(s) bay positions In another event, the Sakuria group has also

Photocatalysis with organic dyes: facile access to reactive intermediates for synthesis

• Stephanie G. E. Amos,
• Marion Garreau,
• Luca Buzzetti and
• Jerome Waser

Beilstein J. Org. Chem. 2020, 16, 1163–1187, doi:10.3762/bjoc.16.103

• intermediate of important reactions, such as the pinacol [101] or the McMurry coupling [102]. Recently, photocatalysis has been used to access ketyl radicals through the reduction of ketones with a suitable transition metal-based photocatalyst [103] or organic dye [104]. The protonation of this type of

Effect of ring size on photoisomerization properties of stiff stilbene macrocycles

• Sandra Olsson,
• Óscar Benito Pérez,
• Magnus Blom and
• Adolf Gogoll

Beilstein J. Org. Chem. 2019, 15, 2408–2418, doi:10.3762/bjoc.15.233

• ]+ calcd for C30H38O4, 463; found, 463; HRMS (CI) m/z: [M + H]+ calcd for C30H38O4, 463.2843; found, 463.2836; UV–vis (CH2Cl2) λmax: 320, 248 nm. General procedure B: McMurry coupling Zinc powder previously grinded (12 equiv) was suspended in dry THF (30 mL). The suspension was cooled to 0 °C in an ice

Synthesis of eunicellane-type bicycles embedding a 1,3-cyclohexadiene moiety

• Alex Frichert,
• Peter G. Jones and
• Thomas Lindel

Beilstein J. Org. Chem. 2018, 14, 2461–2467, doi:10.3762/bjoc.14.222

• McMurry coupling to the diol, followed by two-step epimerization at C2. Assembly of the envisaged cyclization precursor 27. Structure analysis of diastereomeric cyanohydrins 29 and 30. Formation of allenes 32 and 34 from sterically crowded propargylic alcohol 31. Supporting Information Supporting

Selectively fluorinated cyclohexane building blocks: Derivatives of carbonylated all-cis-3-phenyl-1,2,4,5-tetrafluorocyclohexane

• Mohammed Salah Ayoup,
• David B. Cordes,
• Alexandra M. Z. Slawin and
• David O'Hagan

Beilstein J. Org. Chem. 2015, 11, 2671–2676, doi:10.3762/bjoc.11.287

• ratio, respectively, which could be separated by column chromatography. The reaction is illustrated in Scheme 2. The structure of aldehyde 15 was confirmed by X-ray structure analysis and is shown in Figure 2. Transformations of benzaldehyde 15 were explored. For example McMurry coupling [12] of 15 gave

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

• Grignard reagent 71 in the presence of a nickel phosphine complex 72 gave muscopyridine 73 in a single step (Scheme 11). This strategy has been applied to generate a variety of pyridinophanes by varying the chain length of the Grignard reagent. McMurry coupling: Kuroda and co-workers [99] have reported the

• stereochemistry of the newly generated C–C double bonds in 78 was confirmed as trans with the aid of the NMR vicinal coupling constant. Finally, intramolecular McMurry coupling of 78 using titanium trichloride and lithium aluminum hydride (LAH) heated under reflux in THF provided the cyclophane derivative 79 (20

• corresponding dibromide followed by formylation (Scheme 13). In 2006, Rajkumar and co-workers [103] have published the synthesis of stilbenophane 85 via McMurry coupling as a key step (Scheme 14). Terphenyl derivative 82 was subjected to benzylic bromination in the presence of NBS to generate compound 83. Later

The chemical behavior of terminally tert-butylated polyolefins

• Dagmar Klein,
• Henning Hopf,
• Peter G. Jones,
• Ina Dix and
• Ralf Hänel

Beilstein J. Org. Chem. 2015, 11, 1246–1258, doi:10.3762/bjoc.11.139

• particular the distortions associated with the bulky tert-butyl groups. For all these hydrocarbons, di-tert-butylketone (1) served as the starting material, which was chain-elongated by preparative sequences involving standard Wittig, Wittig–Horner and McMurry coupling reactions. Nearly all of the polyenes 2

Attempts to prepare an all-carbon indigoid system

• Şeref Yildizhan,
• Henning Hopf and
• Peter G. Jones

Beilstein J. Org. Chem. 2015, 11, 363–372, doi:10.3762/bjoc.11.42

• Braunschweig, Germany, Fax: (+49)531-391-5387 10.3762/bjoc.11.42 Abstract First attempts are described to prepare a precursor for an all-carbon analog of indigo, the tetracyclic triene 4. Starting from indan-2-one (9) the α-methylene ketone 13 was prepared. Upon subjecting this compound to a McMurry coupling

• dimerized to 30, the conversion of this olefin to 14 failed. Keywords: α-methylene ketones; Cope rearrangement; cross-conjugation; indigo; McMurry coupling; Introduction Cross-conjugated organic molecules are defined as unsaturated systems containing two π-electron systems (or lone pairs) that are in

• -methylene ketone 12, failed (Dess–Martin reaction, IBX, Swern oxidation etc.); the original plan was to dimerize this intermediate to 4 by, e.g., a McMurry coupling reaction. Also the second route, starting with the reaction of 2-indanone (9) with the Eschenmoser salt 10 according to [17] to give the iodide

Directed ortho,ortho'-dimetalation of hydrobenzoin: Rapid access to hydrobenzoin derivatives useful for asymmetric synthesis

• Inhee Cho,
• Labros Meimetis,
• Lee Belding,
• Michael J. Katz,
• Travis Dudding and
• Robert Britton

Beilstein J. Org. Chem. 2011, 7, 1315–1322, doi:10.3762/bjoc.7.154

• McMurry coupling of an ortho-substituted benzaldehyde followed by I2-catalyzed isomerization of the resulting stilbene and subsequent SAD [21][22]. Thus, while various hydrobenzoin derivatives have been reported, their multi-step synthesis, the modest enantioselectivity in the SAD step [22], the problems