Recent advances in the syntheses of anthracene derivatives

• Giovanni S. Baviera and
• Paulo M. Donate

Beilstein J. Org. Chem. 2021, 17, 2028–2050, doi:10.3762/bjoc.17.131

• aromatic ketones (Scheme 27) [61]. The authors coupled acetophenone derivatives 116 and 1,4-benzenediboronates 117 at a 2:1 ratio, to obtain p-terphenyl derivatives 118. In the second step, the conversion of the acetyl group of compounds 118 to an ethynyl group afforded diethynylterphenyls 119. In the last

• anthracenes from a bifunctional organomagnesium alkoxide. Palladium-catalyzed tandem C–H activation/bis-cyclization of propargylic carbonates. Ruthenium-catalyzed C–H arylation of acetophenone derivatives with arenediboronates. Pd-catalyzed intramolecular cyclization of (Z,Z)-p-styrylstilbene derivatives

Development of N-F fluorinating agents and their fluorinations: Historical perspective

• Teruo Umemoto,
• Yuhao Yang and
• Gerald B. Hammond

Beilstein J. Org. Chem. 2021, 17, 1752–1813, doi:10.3762/bjoc.17.123

• -fluoropyridinium triflate 5-4j (Umemoto’s reagent, 58%) and N-fluorosulfonamide 4-1b (Barnette’s reagent, 50%). NFOBS was able to fluorinate 1,3-dimethoxybenzene under neat conditions, while attempts to fluorinate toluene and acetophenone failed. The details of these reactions and applications were described in a

Fritsch–Buttenberg–Wiechell rearrangement of magnesium alkylidene carbenoids leading to the formation of alkynes

• Tsutomu Kimura,
• Koto Sekiguchi,
• Akane Ando and
• Aki Imafuji

Beilstein J. Org. Chem. 2021, 17, 1352–1359, doi:10.3762/bjoc.17.94

• reactivity between geometric isomers, the formation of alkynes via the 1,2-rearrangement of free alkylidene carbenes is unlikely. To gain insight into the reaction mechanism, 13C-labeled sulfoxides [13C]-(E)-2e and [13C]-(Z)-2e were prepared from acetophenone-α-13C and HWE reagent (Scheme 6a), and each

A comprehensive review of flow chemistry techniques tailored to the flavours and fragrances industries

• Guido Gambacorta,
• James S. Sharley and
• Ian R. Baxendale

Beilstein J. Org. Chem. 2021, 17, 1181–1312, doi:10.3762/bjoc.17.90

N-tert-Butanesulfinyl imines in the asymmetric synthesis of nitrogen-containing heterocycles

• Joseane A. Mendes,
• Paulo R. R. Costa,
• Miguel Yus,
• Francisco Foubelo and
• Camilla D. Buarque

Beilstein J. Org. Chem. 2021, 17, 1096–1140, doi:10.3762/bjoc.17.86

• ), which has been shown to display memory-enhancing properties and was also effective for the treatment of cognitive disorders. The reaction of the N-tert-butanesulfinyl imine (SS)-119 with trimethylsilyl enol ether derived from acetophenone 123 in the presence of TMSOTf at low temperature, produced β

[2 + 1] Cycloaddition reactions of fullerene C₆₀ based on diazo compounds

• Yuliya N. Biglova

Beilstein J. Org. Chem. 2021, 17, 630–670, doi:10.3762/bjoc.17.55

• reported [160]. In a study by Kumar and co-workers [161], the synthesis of methanofullerenes 206 and 207 was based on 3-methoxy-4-hydroxycinnamic aldehyde and a chalcon obtained by Claison condensation of acetophenone with 2-hydroxy-5-nitrobenzaldehyde (Scheme 41). Further, the same team obtained

Synthetic strategies of phosphonodepsipeptides

• Jiaxi Xu

Beilstein J. Org. Chem. 2021, 17, 461–484, doi:10.3762/bjoc.17.41

• -dioxaphospholane-4,5-dicarboxylate (168) gave the corresponding phosphonodepsipeptides 169 in 65–86% yields under mild conditions. Although the diisopropyl ester was applied instead of diethyl ʟ-tartrate, a low diastereoselectivity (ratios varied from 55:45 to 67:33) was observed as well. Acetophenone (170

Identification of volatiles from six marine Celeribacter strains

• Anuj Kumar Chhalodia,
• Jan Rinkel,
• Dorota Konvalinkova,
• Jörn Petersen and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2021, 17, 420–430, doi:10.3762/bjoc.17.38

• ). Cyclohexanol (26) was observed only once in C. marinus, and aromatic compounds included benzyl alcohol (27), benzaldehyde (28) and salicylaldehyde (29), acetophenone (30) and o-aminoacetophenone (31), 2-phenylethanol (32), and phenylacetone (33). 6-Methylhept-5-en-2-one (34) was detected in all strains, while

Metal-free nucleophilic trifluoromethylselenolation via an iodide-mediated umpolung reactivity of trifluoromethylselenotoluenesulfonate

• Kevin Grollier,
• Alexis Taponard,
• Arnaud De Zordo-Banliat,
• Emmanuel Magnier and
• Thierry Billard

Beilstein J. Org. Chem. 2020, 16, 3032–3037, doi:10.3762/bjoc.16.252

• acetophenone (3l). This led us to suppose that CF3Se− might be a poor nucleophile, which is confirmed by the medium yield observed with the propargylic substrate 3k, where the chloride starting material was used instead of the bromide as for the other compounds. Noteworthy, because of the volatility of the

A novel and robust heterogeneous Cu catalyst using modified lignosulfonate as support for the synthesis of nitrogen-containing heterocycles

• Bingbing Lai,
• Meng Ye,
• Ping Liu,
• Minghao Li,
• Rongxian Bai and
• Yanlong Gu

Beilstein J. Org. Chem. 2020, 16, 2888–2902, doi:10.3762/bjoc.16.238

• , ring-closing, metathesis, cycloadditions, radical reactions and microwave-assisted reactions [38][39][40]. In this work, we attempt to develop a greener, simpler, more efficient and recyclable system to synthesize arylpyridine derivatives. Initially, the reaction of acetophenone (5a) and 1,3

• the product 10e in 66% yield. Naphthylamine (9f) also reacted positively with 2-(phenylethynyl)acetophenone (8a) and 70% of 10f was obtained. The attempts of aliphatic amines were also successful, obtaining the corresponding products 10g–i in good to excellent yields. It should be noted that secondary

• amines such as morpholine (9j) also showed high reactivity in this reaction and 10j was obtained in 81% yield. The substituent effect of 2-(phenylethynyl)acetophenone was studied subsequently, and the results showed that fluoro, chloro, aliphatic chain and cycloolefin-substituted 2-(phenylethynyl

Photosensitized direct C–H fluorination and trifluoromethylation in organic synthesis

• Shahboz Yakubov and
• Joshua P. Barham

Beilstein J. Org. Chem. 2020, 16, 2151–2192, doi:10.3762/bjoc.16.183

• disclosed the direct C–H fluorination [201] of unactivated alkyl C(sp3)–H bonds using acetophenone as a PSCat, which was photoexcited by near-UV light (375–400 nm, Scheme 12). In the absence of a PSCat and using dedicated UV-light irradiation (275–375 nm), the product was observed together with numerous

• decomposition products (Scheme 13). No reaction was observed using a 19 W CFL bulb in the absence of a PSCat. Despite acetophenone being a colorless oil with only trace absorption above 375 nm (an n–π* transition corresponding to a photon of 325 nm), it successfully functioned as a PSCat, undergoing

• choice of the PSCat. Acetophenone derivatives as well as benzaldehyde, 9-fluorenone, benzophenone derivatives and xanthone were all examined with respect to catalytic loadings (5 mol %), and acetophenone remained the most effective. Despite having stronger absorption bands than acetophenone at visible

Fluorohydration of alkynes via I(I)/I(III) catalysis

• Jessica Neufeld,
• Constantin G. Daniliuc and
• Ryan Gilmour

Beilstein J. Org. Chem. 2020, 16, 1627–1635, doi:10.3762/bjoc.16.135

• fluorination of acetophenone derivatives was achieved using iodosylarenes and commercially available NEt3/HF 1:5 to generate the ArIF2 species in situ is also highly pertinent [39][40] (Figure 1A). Elegant reports describing the conversion of internal alkynes to α-fluoroketones via π-acid catalysis were also

• ]. (A) Synthetic routes to α-fluoroketones from silyl enol ethers or acetophenone derivatives. (B) Selected Au-catalysed syntheses of α-fluoroketones from alkynes. (C) This work: synthesis of α-fluoroketones from pentynyl benzoates via I(I)/I(III) catalysis. X-ray molecular structure of compound 2

Photoredox-catalyzed silyldifluoromethylation of silyl enol ethers

• Vyacheslav I. Supranovich,
• Vitalij V. Levin and
• Alexander D. Dilman

Beilstein J. Org. Chem. 2020, 16, 1550–1553, doi:10.3762/bjoc.16.126

• -electron oxidation thereby supporting a photoredox cycle [22][23][24]. The silyl enol ether 2a derived from acetophenone was selected as a model substrate and the reaction with silane 1 (1.5 equiv) was evaluated (Scheme 2). The reactions were performed in dichloromethane, and reaction mixtures were

Recent applications of porphyrins as photocatalysts in organic synthesis: batch and continuous flow approaches

• Rodrigo Costa e Silva,
• Luely Oliveira da Silva,
• Aloisio de Andrade Bartolomeu,
• Timothy John Brocksom and
• Kleber Thiago de Oliveira

Beilstein J. Org. Chem. 2020, 16, 917–955, doi:10.3762/bjoc.16.83

• and HEH act respectively as electron and hydrogen donors. The protocol was efficient for dehalogenations with bromine- and iodine-containing acetophenone derivatives (75–98% yields). However, it was much less efficient with chloro ketones (12–40% yields) and not effective with α-bromo esters and α

Aldehydes as powerful initiators for photochemical transformations

• Maria A. Theodoropoulou,
• Nikolaos F. Nikitas and
• Christoforos G. Kokotos

Beilstein J. Org. Chem. 2020, 16, 833–857, doi:10.3762/bjoc.16.76

• capable to induce other types of reactions, such as hydrogen atom abstraction (HAT) processes or triplet state energy transfer processes (EnT). Carbonyl compounds, especially diaryl ketones, have shown great potential as far as their catalytic scope is concerned. Benzophenone or acetophenone (64) and

• that did not react with the excited benzaldehyde (9, Scheme 2). Photoorganocatalysts are known for their ability to abstract hydrogen atoms from various substrates, furnishing radical species. Benzophenone is a very well-studied example of this category. Alongside with benzophenone and acetophenone

• of 70 kcal/mol or more produced photostationary mixtures of a trans/cis ratio of ≈1.25. Such compounds were acetophenone (64), benzaldehyde (8), 4-hydroxybenzaldehyde (65), and 2-methoxybenzaldehyde (66). However, 9-anthraldehyde (67), which has a very low-lying triplet state below 50 kcal/mol

Reaction of indoles with aromatic fluoromethyl ketones: an efficient synthesis of trifluoromethyl(indolyl)phenylmethanols using K₂CO₃/n-Bu₄PBr in water

• Thanigaimalai Pillaiyar,
• Masoud Sedaghati and
• Gregor Schnakenburg

Beilstein J. Org. Chem. 2020, 16, 778–790, doi:10.3762/bjoc.16.71

• the reactants was explored by subjecting the reaction of 2,2-difluoro-1-phenylethan-1-one (2i) with 1a. The desired product 3i was obtained in 63% yield. However, no product was formed when the reaction was carried out with 2-fluoro-1-phenylethan-1-one (2j) or acetophenone (2k). The reason could be

p-Pyridinyl oxime carbamates: synthesis, DNA binding, DNA photocleaving activity and theoretical photodegradation studies

• Panagiotis S. Gritzapis,
• Panayiotis C. Varras,
• Nikolaos-Panagiotis Andreou,
• Katerina R. Katsani,
• Konstantinos Dafnopoulos,
• George Psomas,
• Zisis V. Peitsinis,
• Alexandros E. Koumbis and
• Konstantina C. Fylaktakidou

Beilstein J. Org. Chem. 2020, 16, 337–350, doi:10.3762/bjoc.16.33

• [78][80]. Acetophenone (AP) is such a compound, that when initially excited to its first singlet excited state, exhibits a singlet-to-triplet conversion quantum yield close to 100% [81] and has been used for its triplet energy transfer [82]. In order to experimentally prove that DNA dissociation

• oxime carbamates 8–13 might be excited at their triplet states via triplet state energy transfer from acetophenone as a sensitizer, dissociate to their iminyl/carbamoyloxyl and subsequent anilinyl radicals, attack DNA and cleave it (Figure 7). As shown in Figure 8 none of the compounds show any cleavage

• activity seems to be located at the nitro group. The explanation of the activity seems to be the ability of 12 to obtain its triplet state and create active radicals able to abstract hydrogen atoms from DNA and cause its damage. This was experimentally verified using acetophenone, as a triplet state

Extension of the 5-alkynyluridine side chain via C–C-bond formation in modified organometallic nucleosides using the Nicholas reaction

• Renata Kaczmarek,
• Dariusz Korczyński,
• James R. Green and
• Roman Dembinski

Beilstein J. Org. Chem. 2020, 16, 1–8, doi:10.3762/bjoc.16.1

• electron-rich arenes, π-excessive heterocycles, enol derivatives, and allylmetalloids. Specifically, the reactivity of 1,3,5-trimethoxybenzene, N-methylindole, acetophenone trimethylsilyl enol ether, and allyltrimethylsilane was investigated (Table 1). The Nicholas reaction products 6 and 7 (Figure 1) were

• , 825.0000; found, 825.0002. Hexacarbonyl dicobalt 3',5'-di-O-acetyl-2'-deoxy-5-(5-oxo-5-phenylhex-1-yn-1-yl)uridine (6c). To a solution of nucleoside complex 4 (0.0212 g, 30.6 μmol) in CH2Cl2 (5 mL) at 0 °C was added acetophenone trimethylsilyl enol ether (trimethyl(1-phenylvinyloxy)silane, 0.039 g, 0.20

A review of asymmetric synthetic organic electrochemistry and electrocatalysis: concepts, applications, recent developments and future directions

• Munmun Ghosh,
• Valmik S. Shinde and
• Magnus Rueping

Beilstein J. Org. Chem. 2019, 15, 2710–2746, doi:10.3762/bjoc.15.264

• catalyze the enantioselective hydrogenation of prochiral ketones 18. The prochiral ketones such as acetophenone, 1-tetralone and 1-indanone were reduced to their corresponding alcohols 20a, 20b and 20c, respectively, with moderate optical yields, with formation of (S) as major enantiomer (Scheme 5). After

• mixture during the electroreduction of acetophenone on a mercury cathode induces optical activity in the product (alcohol 24a, Scheme 7) [29]. Additionally, pinacol (23) was also obtained via dimerization along with chiral alcohols. The same method was reinvestigated by Wang and Lu in 2013 using a silver

• electrolysis strategy allowed the electroreduction of acetophenone (22a) to pinacol (23) with 6.4% ee (Scheme 21). As mentioned by the author, the radical intermediate diffuses from the double layer, and dimerization occurs in the chiral solvent sphere in the solution phase. Chiral supporting electrolyte

Vicinal difunctionalization of alkenes by four-component radical cascade reaction of xanthogenates, alkenes, CO, and sulfonyl oxime ethers

• Shuhei Sumino,
• Takahide Fukuyama,
• Mika Sasano,
• Ilhyong Ryu,
• Antoine Jacquet,
• Frédéric Robert and
• Yannick Landais

Beilstein J. Org. Chem. 2019, 15, 1822–1828, doi:10.3762/bjoc.15.176

• -substituted sulfonyl oxime ester 3b also worked well to provide cyano-functionalized α-keto oximes. 5i, 5j, and 5k were thus accessible through the four-component coupling reaction between xanthogenates, alkenes, CO, and 3b in acceptable isolated yields (39–50%). Finally, the reaction between acetophenone

Recent advances on the transition-metal-catalyzed synthesis of imidazopyridines: an updated coverage

• Gagandeep Kour Reen,
• Ashok Kumar and
• Pratibha Sharma

Beilstein J. Org. Chem. 2019, 15, 1612–1704, doi:10.3762/bjoc.15.165

• ]pyridines under microwave irradiation [115]. 1-Butyl-3-methylimidazolium tetrafluoroborate ([bmim]BF4) was used as ionic liquid for this three-component reaction of pyridine-2(1H)-one 70, acetophenone 71 and o-tosylhydroxylamine (72, Scheme 25). The reason behind the use of an ionic liquid as reaction

• the viability of the reaction. In this reaction, benzyl cyanide was used as the source of cyanide ions. Mechanistically the reaction involved the simultaneous release of cyanide ions and the α-iodination of acetophenone catalyzed by CuI. Further, the Ortoleva–King reaction of the iodinated ketone 130

Multicomponent reactions (MCRs): a useful access to the synthesis of benzo-fused γ-lactams

• Edorta Martínez de Marigorta,
• Jesús M. de Los Santos,
• Ana M. Ochoa de Retana,
• Javier Vicario and
• Francisco Palacios

Beilstein J. Org. Chem. 2019, 15, 1065–1085, doi:10.3762/bjoc.15.104

• in this manner, although, once again, ortho-substituted anilines 2 did not render the cyclic product, as the final lactamization step is probably impeded by sterical reasons. On the other hand, silyl enol ethers of acetone, acetophenone, methyl acetate, 2-hydroxyfuran and cyclohexanone worked well

• under these conditions and, in place of isoindolinones 53, isobenzofuranones were isolated. The method was extended to the corresponding acetophenone derivative 54 and, in this case, quaternary nitriles and carboxamides 55 were prepared in good yields (Scheme 15, method B). This Strecker approach has

Synthesis of the aglycon of scorzodihydrostilbenes B and D

• Katja Weimann and
• Manfred Braun

Beilstein J. Org. Chem. 2019, 15, 610–616, doi:10.3762/bjoc.15.56

• stilbenes that would serve as the precursors of scorzodihydrostilbenes had failed, presumably due to steric hindrance caused by the accumulation of substituents at the acetophenone moiety [10]. We felt that a straightforward access to the scorzodihydrostilbene aglycons would be possible by using the

• particularly attractive as it leads in an atom-economic manner directly to the carbon skeleton of scorzodihydrostilbenes, starting from suitably substituted acetophenone and styrene derivatives. Furthermore, Murai’s protocol offers another advantage: the regioselective formation of the anti-Markovnikov product

• ): Prepared from 2,4-bis(benzyloxy)acetophenone (6a, 760 mg, 2.3 mmol) and 3,4-dimethoxystyrene (7a, 860 mg, 5.2 mmol) in 2 mL of toluene at 150 °C for 7 d. The crude product was purified by column chromatography (silica gel; ethyl acetate/n-hexane, 1:7) and 8a was obtained as a greenish syrup in 65% yield

Selective benzylic C–H monooxygenation mediated by iodine oxides

• Kelsey B. LaMartina,
• Haley K. Kuck,
• Linda S. Oglesbee,
• Asma Al-Odaini and
• Nicholas C. Boaz

Beilstein J. Org. Chem. 2019, 15, 602–609, doi:10.3762/bjoc.15.55

• by Ishii and co-workers on the aerobic oxidation of cumene in acetic acid using catalytic NHPI and cobalt(II), resulted in a mixture of 2-phenyl-2-propanol, acetophenone, and phenol [60][61]. This lack of selectivity in the product was related in part to the propensity of the cumene hydroperoxide

Asymmetric synthesis of a high added value chiral amine using immobilized ω-transaminases

• Antonella Petri,
• Valeria Colonna and
• Oreste Piccolo

Beilstein J. Org. Chem. 2019, 15, 60–66, doi:10.3762/bjoc.15.6

• , the used TAs-IMB showed a higher stability in the range between 30 °C and 55 °C when the model compound acetophenone was used as substrate. We were interested in exploring the behavior of these enzymes using 1 as starting material. Transamination reactions catalyzed by ATA-025-IMB, ATA-415-IMB, ATA