Multi-redox indenofluorene chromophores incorporating dithiafulvene donor and ene/enediyne acceptor units

• Christina Schøttler,
• Kasper Lund-Rasmussen,
• Line Broløs,
• Philip Vinterberg,
• Ema Bazikova,
• Viktor B. R. Pedersen and
• Mogens Brøndsted Nielsen

Beilstein J. Org. Chem. 2024, 20, 59–73, doi:10.3762/bjoc.20.8

• -olefination reaction was first discovered by Ramirez and co-workers [22] and used in the first step of the Corey–Fuchs reaction that ultimately provides an alkyne [23]. To elucidate the properties of the donor part itself of the pyrrolo-annelated IF-DTF systems, we prepared compounds 16 and 17 containing a

• various elaborate systems [24][25][26][27]. Next, we wanted to explore IF-DTFs as motifs for acetylenic scaffolding (Scheme 4). Starting from IF-DTF building block 6, dibromo-olefinated compound 18 was obtained by a Ramirez/Corey–Fuchs reaction. Two-fold Sonogashira couplings with trimethylsilylacetylene

Combretastatins D series and analogues: from isolation, synthetic challenges and biological activities

• Jorge de Lima Neto and
• Paulo Henrique Menezes

Beilstein J. Org. Chem. 2023, 19, 399–427, doi:10.3762/bjoc.19.31

• hydroxybenzaldehyde 80 into the corresponding acetal followed by Ullmann-type coupling with 52, led to the formation of diaryl ether 83. Subsequent Corey–Fuchs reaction [49] and in situ alkylation led to formation of the propargylic alcohol 85. Deprotection of the aldehyde followed by chain elongation through the

Sequential hydrozirconation/Pd-catalyzed cross coupling of acyl chlorides towards conjugated (2E,4E)-dienones

• Benedikt Kolb,
• Daniela Silva dos Santos,
• Sanja Krause,
• Anna Zens and
• Sabine Laschat

Beilstein J. Org. Chem. 2023, 19, 176–185, doi:10.3762/bjoc.19.17

• via Corey–Fuchs reaction (Table 1) [63]. Starting from different substituted, (E)-configurated enals 28, the respective dibromo-olefines 29 were formed by reaction of 28 with 4 equiv of PPh3 and 2 equiv of CBr4 for 3 h. Treating 29 with 2.2 equiv of n-butyllithium for 1 h resulted in the desired

• % of the dienone 27ea (Table 4, entry 23), whereas the reaction with acetyl chloride (22) gave 65% yield of the desired product 27eq (Table 4, entry 24). In the following series of experiments, substituted enynes 25f–o were employed, which were synthesized beforehand via Corey–Fuchs reaction [63

• with Schwartz's reagent and our work [54][55][57][58][61][62]. Synthesis of substituted enynes 25f–o via Corey–Fuchs reaction and Hunsdiecker reaction. Synthesis of non-natural (a) and natural (b) dienone-containing terpenes: synthesis of β-ionone (3). Synthesis of enynes 25 via Corey–Fuchs reaction

Efficient synthesis of 3,6,13,16-tetrasubstituted-tetrabenzo[a,d,j,m]coronenes by selective C–H/C–O arylations of anthraquinone derivatives

• Seiya Terai,
• Yuki Sato,
• Takuya Kochi and
• Fumitoshi Kakiuchi

Beilstein J. Org. Chem. 2020, 16, 544–550, doi:10.3762/bjoc.16.51

• reaction, followed by dehydrogenative photocyclization, and FeCl3-mediated oxidative cyclization (Scheme 2a) [43]. Tao, Chao, and co-workers succeeded in the preparation of similar tetrasubstituted tetrabenzocoronenes by a Corey–Fuchs reaction, followed by a Suzuki–Miyaura cross-coupling, and a two-step

Synthesis of the polyketide section of seragamide A and related cyclodepsipeptides via Negishi cross coupling

• Jan Hendrik Lang and
• Thomas Lindel

Beilstein J. Org. Chem. 2019, 15, 577–583, doi:10.3762/bjoc.15.53

• )-propylene oxide. The C4–C5 double bond would be formed by Corey–Fuchs reaction. Reaction of the aluminium enolate of tert-butyl propionate (9, Scheme 2) with (S)-propylene oxide had provided Taylor et al. with a mixture of diastereomers of α-methylated γ-hydroxyester 11 favouring the (2S,4S)-syn over the

Electrochemically modified Corey–Fuchs reaction for the synthesis of arylalkynes. The case of 2-(2,2-dibromovinyl)naphthalene

• Fabiana Pandolfi,
• Isabella Chiarotto and
• Marta Feroci

Beilstein J. Org. Chem. 2018, 14, 891–899, doi:10.3762/bjoc.14.76

• alkyne (Et4NBF4) or the bromoalkyne (NaClO4). This study allowed to establish that 2-(bromoethynyl)naphthalene can be converted into 2-ethynylnaphthalene by cathodic reduction. Keywords: arylalkyne; carbon–bromine bond cleavage; cathodic reduction; Corey–Fuchs reaction; 2-(2,2-dibromovinyl)naphthalene

• homologation to terminal alkynes can also be obtained using the Corey–Fuchs reaction [11]. This is a two-step reaction in which an aldehyde is at first converted into a 1,1-dibromoalkene with chain extension by one carbon atom through the reaction with carbon tetrabromide and triphenylphosphine (Scheme 1

• , reaction 1). The second step comprises the conversion of the 1,1-dibromoalkene into the corresponding alkyne by reaction with BuLi at −78 °C in THF (Scheme 1, reaction 2) [12]. Recently, a chemical modification of the second step of the Corey–Fuchs reaction was reported, in which the authors used Cs2CO3 as

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

• amino acid analogues [22][23]. However, epimerization in the α-position frequently occurs under the alkaline reaction conditions of the Seyferth–Gilbert and the Corey–Fuchs reaction. In order to access propargylamines with modified side chains, we chose a de novo synthesis strategy, using Ellman’s

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

A versatile route to polythiophenes with functional pendant groups using alkyne chemistry

• Xiao Huang,
• Li Yang,
• Rikard Emanuelsson,
• Jonas Bergquist,
• Maria Strømme,
• Martin Sjödin and
• Adolf Gogoll

Beilstein J. Org. Chem. 2016, 12, 2682–2688, doi:10.3762/bjoc.12.265

• economically available D-mannitol diketal, 1,2:5,6-bis-O-(1-methylethylidene)-D-mannitol which can be obtained via the hydrogenation of common table sugar [32]. Oxidation of this diketal by NaIO4 led to glyceraldehyde [33], which was transformed into the dibromoolefin 5 by Corey–Fuchs reaction. Dibromoolefin 5

A new approach to ferrocene derived alkenes via copper-catalyzed olefination

• Vasily M. Muzalevskiy,
• Aleksei V. Shastin,
• Alexandra D. Demidovich,
• Namiq G. Shikhaliev,
• Abel M. Magerramov,
• Victor N. Khrustalev,
• Rustem D. Rakhimov,
• Sergey Z. Vatsadze and
• Valentine G. Nenajdenko

Beilstein J. Org. Chem. 2015, 11, 2072–2078, doi:10.3762/bjoc.11.223

• –Fuchs reaction) using a 2–4-fold molar excess of triphenylphosphine [27][28][29][30][31]. Results and Discussion Synthesis of halovinylferrocenes A few years ago we discovered a new reaction for a double carbon–carbon bond formation – the reaction of catalytic olefination. It was shown that the copper

• methods for the preparation of ethynylferrocenes [24][25][26][27][28][29]. In most cases, the key reagents for the synthesis of ethynylferrocene are the corresponding mono- and dihalogenvinylferrocene derivatives. These compounds are generally prepared using a variation of the Wittig reaction (the Corey

The application of a monolithic triphenylphosphine reagent for conducting Ramirez gem-dibromoolefination reactions in flow

• Kimberley A. Roper,
• Malcolm B. Berry and
• Steven V. Ley

Beilstein J. Org. Chem. 2013, 9, 1781–1790, doi:10.3762/bjoc.9.207

• -dibromovinyl)benzene (3) in 84% yield. Triphenylphosphine oxide (4) was also isolated from the reaction as a byproduct. These gem-dibromoolefin products are particularly important intermediates in the one carbon homologation of an aldehyde into the corresponding terminal alkyne, known as the Corey–Fuchs

• reaction [42], and more recently stereospecific hydrogenolysis, Stille and Suzuki reactions have been used to further elaborate these useful products [43][44][45]. The triphenylphosphine oxide byproduct can often be difficult to remove from the reaction mixture, requiring extensive, time-consuming

Bromination of hydrocarbons with CBr₄, initiated by light-emitting diode irradiation

• Yuta Nishina,
• Bunsho Ohtani and
• Kotaro Kikushima

Beilstein J. Org. Chem. 2013, 9, 1663–1667, doi:10.3762/bjoc.9.190

• Corey–Fuchs reaction [29], to obtain terminal alkynes. Although CBr4 has been used for various bromination reactions including radical brominations, these reactions need further additives to proceed. Here, we disclose the efficient bromination of saturated hydrocarbons, using CBr4 as a bromine source

Some aspects of radical chemistry in the assembly of complex molecular architectures

• Béatrice Quiclet-Sire and
• Samir Z. Zard

Beilstein J. Org. Chem. 2013, 9, 557–576, doi:10.3762/bjoc.9.61

• –Fuchs reaction followed by quenching of the acetylide with cyclohexanone furnishes propargyl silane 136, a compound that is cleanly transformed into allene 137 upon exposure to tetrabutylammonium fluoride [54]. This approach represents perhaps the most versatile route to functional propargyl silanes

• possesses an interesting combination of functional groups. Upon treatment with magnesium turnings in methanol, this compound is converted into cyclopentanol 135 by capture of the intermediate ketyl radical by the dichlorovinyl group [55]. Alternatively, protection of the ketone and application of the Corey