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

Volatiles from the hypoxylaceous fungi Hypoxylon griseobrunneum and Hypoxylon macrocarpum

• Jan Rinkel,
• Alexander Babczyk,
• Tao Wang,
• Marc Stadler and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2018, 14, 2974–2990, doi:10.3762/bjoc.14.277

• main compounds, and the trace compounds 2-acetylfuran (30), 2-acetylthiazole (31), acetophenone (33), 1-phenylethanol (34), 1-phenylpropan-1,2-dione (36) and m-cresol (37) were readily identified from their mass spectra and retention indices and by comparison to authentic standards. The main compounds

An overview on recent advances in the synthesis of sulfonated organic materials, sulfonated silica materials, and sulfonated carbon materials and their catalytic applications in chemical processes

• Hashem Sharghi,
• Pezhman Shiri and
• Mahdi Aberi

Beilstein J. Org. Chem. 2018, 14, 2745–2770, doi:10.3762/bjoc.14.253

• multicomponent Mannich-type synthesis of β-aminocarbonyl products 16 in suitable times and yields (Scheme 2). To check the reusability of the catalysts, the reaction between benzaldehyde, aniline, and acetophenone in 5 mmol scale in ethanol was chosen. All catalysts were recycled three times using filtration of

Design and synthesis of C₃-symmetric molecules bearing propellane moieties via cyclotrimerization and a ring-closing metathesis sequence

• Sambasivarao Kotha,
• Saidulu Todeti and
• Vikas R. Aswar

Beilstein J. Org. Chem. 2018, 14, 2537–2544, doi:10.3762/bjoc.14.230

• (9) in the presence of triethylamine (Et3N) in toluene at 140 °C to obtain the acetophenone derivative 10 in excellent yield (92%) [43]. Later, the acetophenone derivative 10 was subjected to trimerization reaction under ethanol/silicon tetrachloride (EtOH/SiCl4) conditions to deliver the trimerized

• Et3N in toluene at 140 ºC to deliver the acetophenone derivative 18 (91% yield) and it was subjected to trimerization in the presence of EtOH/SiCl4 at 0 °C to rt to obtain the trimerized product 19 in 64% yield. Afterwards, the trimerized product 19 was treated with allyl bromide to accomplish C

Novel photochemical reactions of carbocyclic diazodiketones without elimination of nitrogen – a suitable way to N-hydrazonation of C–H-bonds

• Liudmila L. Rodina,
• Xenia V. Azarova,
• Jury J. Medvedev,
• Dmitrij V. Semenok and
• Valerij A. Nikolaev

Beilstein J. Org. Chem. 2018, 14, 2250–2258, doi:10.3762/bjoc.14.200

• with CH2- and O-bridges in their structure, diazoindandione 1f, diazocyclopentenedione 1g, and as a С–Н donor tetrahydrofuran was employed in the study (Figure 1). To determine the most efficient conditions for this reaction with diazodiketones 1, three sensitizers, acetophenone, benzophenone, and

• used in this study (acetophenone, benzophenone and Michler’s ketone) demonstrate that they show appropriate absorption of the actinic light at the irradiation conditions of diazodiketones 1 (Supporting Information File 1, Table S2). The sensitized photoreactions of diazodiketones 1a–g were carried out

• the light-induced reaction studied in the series of acetophenone, benzophenone, and Michler’s ketone was found to be benzophenone. The application of acetophenone reduced the yield of hydrazone 2b by about 1/4 as compared to benzophenone (from 52 to 40%; Table 1, entries 6 and 8). With Michler’s

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

• Tsuyoshi Mita Masashi Uchiyama Kenichi Michigami Yoshihiro Sato Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo 060-0812, Japan 10.3762/bjoc.14.176 Abstract We herein describe a cobalt/Xantphos-catalyzed regioselective addition of simple alkenes to acetophenone derivatives

• allylic C(sp3)–H addition of α-olefins, mainly 1-undecene and their analogues, to ketone electrophiles. Results and Discussion We initially conducted screening of conditions using 1 equiv of 1-undecene (1a) and 3 equiv of acetophenone (2a) as starting materials (Table 1). When the reaction was conducted

• addition of allylarene to acetophenone that exhibited high linear selectivity [29], perfect branch selectivity was observed using 1a as a substrate. When the reaction temperature was raised, the yield of 3aa was improved to 45% yield at 90 °C (Table 1, entries 2 and 3). An increase in the amount of AlMe3

Mild and selective reduction of aldehydes utilising sodium dithionite under flow conditions

• Nicole C. Neyt and
• Darren L. Riley

Beilstein J. Org. Chem. 2018, 14, 1529–1536, doi:10.3762/bjoc.14.129

• benzaldehyde in the presence of various ketones at equal concentrations (Table 3). In all cases benzaldehyde was efficiently reduced (71–91% conversion as determined by 1H NMR) and the ketones remained largely unreduced with only acetophenone (9%) and 4-chloroacetophenone (8%) affording conversions above 1

Recent applications of chiral calixarenes in asymmetric catalysis

• Mustafa Durmaz,
• Erkan Halay and
• Selahattin Bozkurt

Beilstein J. Org. Chem. 2018, 14, 1389–1412, doi:10.3762/bjoc.14.117

• ) reduction In 2011, Katz et al. developed two optically pure aluminum complexes of inherently chiral calix[4]arene 111 and 112 bearing also an asymmetric carbon center on the phenylethylamine substituent (Scheme 33) as catalysts for asymmetric Meerwein–Ponndorf–Verley (MPV) reduction of acetophenone

Cross-coupling of dissimilar ketone enolates via enolonium species to afford non-symmetrical 1,4-diketones

• Keshaba N. Parida,
• Gulab K. Pathe,
• Shimon Maksymenko and
• Alex M. Szpilman

Beilstein J. Org. Chem. 2018, 14, 992–997, doi:10.3762/bjoc.14.84

• -coupling of 4 (R1 = Ph, R2 = H) with the TMS enol ether 5 (R3 = p-MeOC6H4, R4 = H) afforded compound 8 in 72% yield with no oxidation of the electron-rich aromatic ring observed. The only side product being tosyloxy-acetophenone. The same enolonium species 4 (R1 = Ph, R2 = H) reacts with the TMS enol ether

• 5 (R3 = p-O2NC6H4, R4 = H) to form 9 in 65% yield. The method is by no means restricted to enolonium species of acetophenone as may be observed from the formation of the whole series of para-halogenated 1,4-diketones. Thus, the p-fluoro-, p-chloro-, and p-bromo-substituted enolonium species 4 (R3

Volatiles from the xylarialean fungus Hypoxylon invadens

• Jeroen S. Dickschat,
• Tao Wang and
• Marc Stadler

Beilstein J. Org. Chem. 2018, 14, 734–746, doi:10.3762/bjoc.14.62

• 2-phenylethanol (10), and the trace components acetophenone (9), terpinen-4-ol (13), and indole (16). For several other compounds in the headspace extract close hits for highly substituted aromatic compounds were found in our mass spectral libraries, but the mass spectra and retention indices for

An alternative to hydrogenation processes. Electrocatalytic hydrogenation of benzophenone

• Cristina Mozo Mulero,
• Alfonso Sáez,
• Jesús Iniesta and
• Vicente Montiel

Beilstein J. Org. Chem. 2018, 14, 537–546, doi:10.3762/bjoc.14.40

• ohmic drop at the whole process. In the case of organic electrosynthesis, electrocatalytic hydrogenation of aromatic ketones, specifically acetophenone, has been recently carried out [22][23] achieving a high selectivity using the above-mentioned technology. In this work, we have chosen benzophenone, as

Conformational preferences of α-fluoroketones may influence their reactivity

• Graham Pattison

Beilstein J. Org. Chem. 2017, 13, 2915–2921, doi:10.3762/bjoc.13.284

• -fluorinated ketones was not the expected outcome through simple arguments of electronegativity differences. Comparison of the reactivity of each α-haloacetophenone to non-halogenated acetophenone showed the halogenated derivatives to be significantly more reactive (no reduction of acetophenone could be

• -haloacetophenone, calculating the energy of each compound as the carbon–halogen bond is rotated through 10° increments in both the gas phase and in ethanol as reaction solvent (Figure 1) [10]. The fluorinated acetophenone showed significant differences in conformational energy to the chlorinated and brominated

• reactive conformations more accessible to the fluorinated acetophenone. Potential reasons for the different conformational preferences of the α-halogenated acetophenones were then examined. One possibility is that the increased electronegativity of fluorine induces a high dipole moment at small O=C–C–X