Cu(OTf)₂-catalyzed multicomponent reactions

• Sara Colombo,
• Camilla Loro,
• Egle M. Beccalli,
• Gianluigi Broggini and
• Marta Papis

Beilstein J. Org. Chem. 2025, 21, 122–145, doi:10.3762/bjoc.21.7

• reactions conducted step by step. Providing acyclic compounds A three-component Strecker-type condensation of aromatic aldehydes, amines, and cyanides under mild reaction conditions furnishes α-aminonitriles 1 in good to high yields (Scheme 1) [15]. The reaction failed only in the case of acetophenone

• reactions starting from different reagents. In a first approach proposed by Meshram and co-workers, pyridin-2-one, O-tosylhydroxylamine and acetophenone treated in an ionic liquid assembled through the cascade formation of three C–N bonds to give the imidazo[1,2-a]pyridine scaffold 33 (Scheme 25) [43]. The

• the mechanism is the attack of the protonated pyridin-2-one to the copper-complex of the enamine XXXII resulting from the reaction between acetophenone and O-tosylhydroxylamine, which occurs with elimination of TsOH. The so-obtained imino–copper complex XXXIII gives rise to an intramolecular C–N bond

N-Glycosides of indigo, indirubin, and isoindigo: blue, red, and yellow sugars and their cancerostatic activity

• Peter Langer

Beilstein J. Org. Chem. 2024, 20, 2840–2869, doi:10.3762/bjoc.20.240

• -glycososides 3-Alkylideneoxindoles are of considerable pharmacological relevance and occur in a variety of clinically used drugs and natural products [42][43][44][45]. The reaction of isatin-N-rhamnoside 16a with acetophenone (45a) afforded the desired 3-alkylideneoxindole-N-rhamnoside E-β-46a in good yield as

Mechanochemical difluoromethylations of ketones

• Jinbo Ke,
• Pit van Bonn and
• Carsten Bolm

Beilstein J. Org. Chem. 2024, 20, 2799–2805, doi:10.3762/bjoc.20.235

• was obtained. Furthermore, most isolated products had only purities of ca. 90% still containing inseparable impurities (as revealed by NMR spectroscopy). In the first series of substrates, acetophenone derivatives with various para-substituents were applied. Similar to methyl tolyl ketone (1a), which

• afforded product 3a in 74% yield, acetophenone (1b) gave 3b in 56% yield. Substrates 1c and 1d bearing a chloro or a bromo group in para position of the aryl moiety, gave the corresponding products in yields of 53% (for 3c) and 42% (for 3d). These two difluoromethyl enol ethers were also isolated by column

Ring opening of photogenerated azetidinols as a strategy for the synthesis of aminodioxolanes

• Henning Maag,
• Daniel J. Lemcke and
• Johannes M. Wahl

Beilstein J. Org. Chem. 2024, 20, 1671–1676, doi:10.3762/bjoc.20.148

• % yield along with 14% acetophenone (6) as the major side product (Table 1, entry 1). Acetophenone (6) is thought to be generated by a Norrish type II cleavage of biradical 2a. Changes at the aromatic core, as demonstrated by acetonaphthone 1b, resulted in low conversions (Table 1, entry 2). When

Manganese-catalyzed C–C and C–N bond formation with alcohols via borrowing hydrogen or hydrogen auto-transfer

• Mohd Farhan Ansari,
• Atul Kumar Maurya,
• Abhishek Kumar and
• Saravanakumar Elangovan

Beilstein J. Org. Chem. 2024, 20, 1111–1166, doi:10.3762/bjoc.20.98

• investigated using four different well-defined phosphine substituents-containing Mn complexes with acetophenone and benzyl alcohol as model substrates. Among these, complex Mn1 showed better results with 2 mol % loading and at low base concentration (Cs2CO3; 5 mol %) in tert-amyl alcohol at 140 °C for 22 h

• ) as a base in toluene at 140 °C for 36 h that gave up to 84% yield (Scheme 29A). More interestingly, double alkylation also occurred in one pot using acetophenone and 4-methoxyacetophenone with different benzyl alcohols under the optimized conditions. In the first step, monoalkylation of the methyl

• alcohols as an alkylating agent using the protic functionality on a naphthyridine‑N‑oxide manganese complex [68]. The reaction conditions were optimized using acetophenone and benzyl alcohol as model substrates. After optimizing various reaction parameters, 2 mol % of Mn14 and 20 mol % of KOH in toluene

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

• , Shang and Fu initially demonstrated this approach by utilizing catalytic amounts of triphenylphosphine (PPh3) and sodium iodide (NaI) [67]. Upon formation of EDA complex 80, radical addition to silyl enol ether 81 was promoted under blue light irradiation, affording acetophenone product 82 (Scheme 16A

1-Butyl-3-methylimidazolium tetrafluoroborate as suitable solvent for BF₃: the case of alkyne hydration. Chemistry vs electrochemistry

• Marta David,
• Elisa Galli,
• Richard C. D. Brown,
• Marta Feroci,
• Fabrizio Vetica and
• Martina Bortolami

Beilstein J. Org. Chem. 2023, 19, 1966–1981, doi:10.3762/bjoc.19.147

• . Hydration of phenylacetylene 1d carried out with 3 equiv of BF3·Et2O for 5 h gave the aldol condensation product 3d (58%) in addition to acetophenone 2d with low yield (32%) (see Table S1, Supporting Information File 1). Assuming that enone 3d is formed from acetophenone, catalysed by the excess Lewis acid

Application of N-heterocyclic carbene–Cu(I) complexes as catalysts in organic synthesis: a review

• Nosheen Beig,
• Varsha Goyal and
• Raj K. Bansal

Beilstein J. Org. Chem. 2023, 19, 1408–1442, doi:10.3762/bjoc.19.102

• allow to synthesize acylboron compounds [54]. As mentioned earlier, Oro and co-workers [39] used 5 mol % of complex 78a (Scheme 27) for the homogeneous hydrosilylation of acetophenone with HSiEt3 in the presence of KOt-Bu. As indicated by 1H NMR spectroscopy, the conversion was complete in 18 h

Mechanochemical solid state synthesis of copper(I)/NHC complexes with K₃PO₄

• Ina Remy-Speckmann,
• Birte M. Zimmermann,
• Mahadeb Gorai,
• Martin Lerch and
• Johannes F. Teichert

Beilstein J. Org. Chem. 2023, 19, 440–447, doi:10.3762/bjoc.19.34

• why we also tested 5bm in these transformations: The 1,2-reduction of benzaldehyde (14) and acetophenone (15) proceeded with good yields (Scheme 3c). No aldol addition for the acetophenone substrate has been observed although working under strongly basic conditions [68][69]. Conclusion In conclusion

1,4-Dithianes: attractive C2-building blocks for the synthesis of complex molecular architectures

• Bram Ryckaert,
• Ellen Demeyere,
• Frederick Degroote,
• Hilde Janssens and
• Johan M. Winne

Beilstein J. Org. Chem. 2023, 19, 115–132, doi:10.3762/bjoc.19.12

• opens up options for Corey–Seebach-type alkylation reactivity with a wider range of electrophiles. The method is demonstrated by the smooth lithiation and subsequent alkylation of the acetophenone-derived dithiin 50 (Scheme 10a) [42]. Palumbo’s elegant overall approach to dihydrodithiin-mediated

Cyclometalated iridium complexes-catalyzed acceptorless dehydrogenative coupling reaction: construction of quinoline derivatives and evaluation of their antimicrobial activities

• Hongling Shui,
• Yuhong Zhong,
• Renshi Luo,
• Zhanyi Zhang,
• Jiuzhong Huang,
• Ping Yang and
• Nianhua Luo

Beilstein J. Org. Chem. 2022, 18, 1507–1517, doi:10.3762/bjoc.18.159

• reaction between 2-aminobenzaldehyde (5) and 1-phenylethanol (2a) catalyzed by cyclometalated iridium TC-6 (Figure 4a). In the same way, quinoline 3aa could also be synthesized from 2-aminobenzyl alcohol (1a) and acetophenone (6) with TC-6 as the catalyst (Figure 4b). Further study found that quinoline 3aa

• could be obtained by the condensation reaction of 2-aminobenzaldehyde (5) with acetophenone (6) in the absence of cyclometalated iridium (Figure 4c). According to experimental results and literature findings [19][28][29][43][44], a possible mechanism of cyclometalated iridium-catalyzed ADC reaction was

• proposed (Figure 5). Firstly, by the interaction of TC-6 with 1a/2a under the “dehydrogenative” process, the Int-I/Int-II were formed [28][29]. Then, Int-III and 2-aminobenzaldehyde (5)/acetophenone (6) were formed by β-H elimination of Int-I/Int-II. In this process, an amount of liberated H2 would be

Electro-conversion of cumene into acetophenone using boron-doped diamond electrodes

• Mana Kitano,
• Tsuyoshi Saitoh,
• Shigeru Nishiyama,
• Yasuaki Einaga and
• Takashi Yamamoto

Beilstein J. Org. Chem. 2022, 18, 1154–1158, doi:10.3762/bjoc.18.119

• 10.3762/bjoc.18.119 Abstract A straightforward electro-conversion of cumene into acetophenone has been reported using boron-doped diamond (BDD) electrodes. This particular conversion is driven by the addition reaction of a cathodically generated hydroperoxide anion to an anodically generated cumyl cation

• hydroperoxide/dicumyl peroxide/phenol from cumene, acetophenone from ethylbenzene, and others. Generally, molecular oxygen has been utilized in the straightforward oxidation of aromatic alkyls. However, since molecular oxygen is highly stable, activation of the molecular oxygen itself is necessary, which

• , which is difficult to achieve with other conventional electrode materials. Herein, we report the straightforward electro-conversion of cumene, one of the most important and extensively investigated aromatic alkyls, by BDD electrodes. Acetophenone was obtained as the main product when BDD was used as the

Electrochemical formal homocoupling of sec-alcohols

• Kosuke Yamamoto,
• Kazuhisa Arita,
• Masashi Shiota,
• Masami Kuriyama and
• Osamu Onomura

Beilstein J. Org. Chem. 2022, 18, 1062–1069, doi:10.3762/bjoc.18.108

• corresponding pinacol-type product 2a was obtained in 58% yield with an 89:11 ratio of dl and meso isomers (Table 1, entry 1). Acetophenone (3a) was also formed in 32% yield under the reaction conditions described in entry 1. Using different electrode materials such as Ni, Zn, and graphite as cathode did not

• reaction, several control experiments were conducted as shown in Scheme 5. When acetophenone (3a) was used as a starting material under the standard reaction conditions, vic-1,2-diol 2a and 3a were obtained in 39% and 52% yields, respectively, and 1-phenylethanol (1a) was not observed in this reaction

Electrochemical hydrogenation of enones using a proton-exchange membrane reactor: selectivity and utility

• Koichi Mitsudo,
• Haruka Inoue,
• Yuta Niki,
• Eisuke Sato and
• Seiji Suga

Beilstein J. Org. Chem. 2022, 18, 1055–1061, doi:10.3762/bjoc.18.107

• electroreduction of 1a would afford 2a directly and not via 4a. Electroreduction of acetophenone did not proceed efficiently, and 42.5% (GC ratio) of acetophenone was recovered with ethylbenzene as a major reduced product (Scheme 4b). We assumed that the reduction would proceed via an enol or enolate intermediate

Synthetic strategies for the preparation of γ-phostams: 1,2-azaphospholidine 2-oxides and 1,2-azaphospholine 2-oxides

• Jiaxi Xu

Beilstein J. Org. Chem. 2022, 18, 889–915, doi:10.3762/bjoc.18.90

• complex showed 23% enantiomeric excess in the asymmetric borane reduction of acetophenone in THF at room temperature (Scheme 33) [58]. The reaction of 3-(phenylaminomethylene)-2-phenylamino-6-methyl-2,3-dihydro-4H-chromen-4-one (213) and diethyl phosphite at 90–100 °C generated 2-ethoxy-6-methyl-2-oxo-1

Synthesis of odorants in flow and their applications in perfumery

• Merlin Kleoff,
• Paul Kiler and
• Philipp Heretsch

Beilstein J. Org. Chem. 2022, 18, 754–768, doi:10.3762/bjoc.18.76

• , an excess of benzaldehyde is used. At 140 °C and with a long residence time of 76 h, a moderate heptanal (34) conversion of 36% was achieved providing jasmonal (35) in a selectivity of 41% [38]. One of the least expensive floral odorants is acetophenone (38), having a “pungent-sweet odor, in dilution

• resembling that of hawthorn or a harsh orange-blossom type“. Acetophenone appears in vintage Geoffrey Beene: Grey Flannel at 0.14%, and Shiseido: Zen and Gap: Om at approx. 0.014%. In 2013, Roberge, Kappe, and co-workers investigated the C–H oxidation of ethylbenzene (37) to acetophenone with oxygen as an

• oxidant (Scheme 8B) [39]. The process is performed at 120 °C at 10 bar with a residence time of 6 min, and catalyzed homogenously utilizing the established “MC-system” (manganese/cobalt/bromide) in a heated tube reactor. Remarkably, acetophenone is obtained in a good yield of 66% and in 96% purity without

Inductive heating and flow chemistry – a perfect synergy of emerging enabling technologies

• Conrad Kuhwald,
• Sibel Türkhan and
• Andreas Kirschning

Beilstein J. Org. Chem. 2022, 18, 688–706, doi:10.3762/bjoc.18.70

• acetophenone 51 were reacted in a heated fixed-bed reactor with the mediation of zinc to give the Reformatsky product 53, and, as commonly observed, in significantly improved yields compared to the corresponding batch processes. Oxidations, especially metal oxide-based variants, are among the most frequently

Tetraphenylethylene-embedded pillar[5]arene-based orthogonal self-assembly for efficient photocatalysis in water

• Zhihang Bai,
• Krishnasamy Velmurugan,
• Xueqi Tian,
• Minzan Zuo,
• Kaiya Wang and
• Xiao-Yu Hu

Beilstein J. Org. Chem. 2022, 18, 429–437, doi:10.3762/bjoc.18.45

• ) gave acetophenone (2a) as product in good yield (97%) under white light irradiation for 2 hours (Table 1 and Supporting Information File 1, Figure S6). In comparison, we added an internal standard (1,3,5-trimethoxybenzene) to the final crude reaction mixture and calculated the NMR yield of the product

• collected in Supporting Information File 1): good yields were observed for 4-methylacetophenone (2b, 97%, Figure S9), 3-methoxyacetophenone (2c, 87%, Figure S10), 4-chloroacetophenone (2d, 76%, Figure S11), and 4-(trifluoromethyl)acetophenone (2e, 86%, Figure S12) and a moderate yield was obtained for 2

• transfer from EsY•− to the substrate α-bromoacetophenone (1a) gives the corresponding acetophenone radical, whilst EsY•− is oxidized to EsY. The acetophenone radical combines with a H-atom abstracted from the radical cation of the Hantzsch ester to form acetophenone (2a) as the final product and diethyl

Recent advances and perspectives in ruthenium-catalyzed cyanation reactions

• Thaipparambil Aneeja,
• Cheriya Mukkolakkal Abdulla Afsina,
• Padinjare Veetil Saranya and
• Gopinathan Anilkumar

Beilstein J. Org. Chem. 2022, 18, 37–52, doi:10.3762/bjoc.18.4

• carbonyl compounds under environmentally benign conditions. This method provides an efficient synthetic route towards alkyl iodides and nitriles in one pot. Carbonyl compounds such as cinnamaldehyde, acetophenone, and cyclohexanone etc. were well tolerated in this reaction and afforded the corresponding

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