1,2-Difluoroethylene (HFO-1132): synthesis and chemistry

• Liubov V. Sokolenko,
• Taras M. Sokolenko and
• Yurii L. Yagupolskii

Beilstein J. Org. Chem. 2024, 20, 1955–1966, doi:10.3762/bjoc.20.171

• meso form in high combined yield (90%, Scheme 16) [94]. The product was used as a ligand for the preparation of transitional metal carbonyl complexes. The addition reaction of trichlorofluoromethane (CFC-11) to 1,2-difluoroethylene in the presence of aluminum chloride under pressure was described [51

Divergent role of PIDA and PIFA in the AlX₃ (X = Cl, Br) halogenation of 2-naphthol: a mechanistic study

• Kevin A. Juárez-Ornelas,
• Manuel Solís-Hernández,
• Pedro Navarro-Santos,
• J. Oscar C. Jiménez-Halla and
• César R. Solorio-Alvarado

Beilstein J. Org. Chem. 2024, 20, 1580–1589, doi:10.3762/bjoc.20.141

• : MeCN) ω-B97XD/(6-311G(d,p),LANL08d)//ω-B97XD/6-31G(d), LANL08d. Chlorination mechanism The reaction mechanism for the chlorination of 2-naphthol using one equivalent of PIFA and two equivalents of aluminum chloride is outlined in Scheme 4. The chlorination mechanism starts when PIFA coordinates the

• first equivalent of aluminum chloride to give the corresponding adduct PIFA–AlCl3. Next, a chlorine atom is transferred to the iodine(III) center to yield I-1–Cl via TS1–Cl with the release of the complex TFAO–AlCl2. Then, the second equivalent of aluminum chloride coordinates the TFAO ligand, giving

• –AlCl2 complex yields the final product 1-chloro-2-naphthol (P–Cl). The calculated mechanism for the chlorination reaction starts with coordination of a PIFA oxygen atom to aluminum chloride. This generates a highly exergonic PIFA–AlCl3 adduct. In Figure 1, the Gibbs free energy of this adduct is set as

Kinetically stabilized 1,3-diarylisobenzofurans and the possibility of preparing large, persistent isoacenofurans with unusually small HOMO–LUMO gaps

• Qian Liu and
• Glen P. Miller

Beilstein J. Org. Chem. 2024, 20, 1099–1110, doi:10.3762/bjoc.20.97

• 199.60, 141.23, 139.54, 136.54, 136.07, 131.22, 130.38, 129.00, 21.17, 20.29. For an alternative synthesis, see [14]. 1,2-Phenylenebis((2,4,6-triethylphenyl)methanone) (22) To a 100 mL round bottom flask equipped with a stir bar was added anhydrous aluminum chloride (0.66 g, 4.9 mmol) and 10 mL of CH2Cl2

• , 123.39, 121.93, 119.78, 21.22, 20.49; UV–vis λmax (7 × 10−5 M in CH2Cl2): 364.3 nm; HRESIMS: calcd for [M + H]+, 355.2062; found, 355.2042. For an alternative synthesis, see [13]. 1,2-Phenylenebis(mesitylmethanone) (21) To a 100 mL round bottom flask equipped with a stir bar was added anhydrous aluminum

• chloride (0.26 g, 2.0 mmol) and 10 mL of CH2Cl2 solvent. An addition funnel was attached and to this was added phthaloyl dichloride (0.20 g, 0.99 mmol) and 5 mL CH2Cl2. The content of the addition funnel was added dropwise into the round bottom flask over 5 minutes with stirring. The addition funnel was

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

• -acid 165. Employing again the Mitsunobu conditions, 11-OMe-isocorniculatolide A (8) was obtained in 85% overall yield after 5 steps. Subsequent cleavage of the methyl ether using aluminum chloride led to isocorniculatolide A (7) in 94% yield after 6 reaction steps and an overall yield of 62% (Scheme 32

Ready access to 7,8-dihydroindolo[2,3-d][1]benzazepine-6(5H)-one scaffold and analogues via early-stage Fischer ring-closure reaction

• Irina Kuznetcova,
• Felix Bacher,
• Daniel Vegh,
• Hsiang-Yu Chuang and
• Vladimir B. Arion

Beilstein J. Org. Chem. 2022, 18, 143–151, doi:10.3762/bjoc.18.15

• the lactam ring of 3a. Gratifyingly, we obtained scaffold C in 71% yield by refluxing 3a with aluminum chloride in benzene (Scheme 6) [43]. For comparison, debenzylation of paullone with sodium in liquid ammonia gave A in 40% yield [23]. In addition, the generality of synthetic pathway (c) (Scheme 1

AlBr₃-Promoted stereoselective anti-hydroarylation of the acetylene bond in 3-arylpropynenitriles by electron-rich arenes: synthesis of 3,3-diarylpropenenitriles

• Yelizaveta Gorbunova,
• Dmitry S. Ryabukhin and
• Aleksander V. Vasilyev

Beilstein J. Org. Chem. 2021, 17, 2663–2667, doi:10.3762/bjoc.17.180

• 2m correspondingly were obtained; other regioisomers were not isolated in amounts that were high enough for their identification. This transformation was also tested with another strong Lewis acid, aluminum chloride (AlCl3), for the reaction of nitrile 1a with benzene. However, in this case, mainly

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

• substituted anthraquinones 166 aiming at further preparation of 9,10-diphenyltanthracenes 167 (Scheme 37) [71]. First, they reacted arenes 163 with phthalic anhydride (164) in the presence of aluminum chloride and hydrochloric acid, to obtain benzoylbenzoic acid derivatives 165. Then, the H3PO4-promoted

Ferrocenyl-substituted tetrahydrothiophenes via formal [3 + 2]-cycloaddition reactions of ferrocenyl thioketones with donor–acceptor cyclopropanes

• Grzegorz Mlostoń,
• Mateusz Kowalczyk,
• André U. Augustin,
• Peter G. Jones and
• Daniel B. Werz

Beilstein J. Org. Chem. 2020, 16, 1288–1295, doi:10.3762/bjoc.16.109

• dicarboxylate (5a) and ferrocenyl phenyl thioketone (8a) in CH2Cl2 at room temperature using aluminum chloride (AlCl3) as a catalyst. The reaction was monitored by TLC, and was shown to be complete after 1 h. The crude reaction mixture was examined by 1H NMR, revealing the formation of a single product with

Architecture and synthesis of P,N-heterocyclic phosphine ligands

• Wisdom A. Munzeiwa,
• Bernard Omondi and
• Vincent O. Nyamori

Beilstein J. Org. Chem. 2020, 16, 362–383, doi:10.3762/bjoc.16.35

• was effected with aluminum chloride [90] and in case of the pyrazinyl derivative, sodium ethanethiolate [91] was used. The generated compounds 93 were then converted into triflate derivatives 94 by treatment with triflic anhydride in the presence of N,N-dimethyl-4-aminopyridine (DMAP) as the catalyst

[1,3]/[1,4]-Sulfur atom migration in β-hydroxyalkylphosphine sulfides

• Katarzyna Włodarczyk,
• Piotr Borowski and
• Marek Stankevič

Beilstein J. Org. Chem. 2020, 16, 88–105, doi:10.3762/bjoc.16.11

• -alkenylphosphine sulfides 62 and 63 (a mixture of E- and Z-isomer) was obtained under each reaction condition tested. Once all the compounds had been prepared, it was decided to test the reactivity of mesylates 60 and 61 in the presence of AlCl3 (Scheme 7). The reaction of these compounds with aluminum chloride

N-(1-Phenylethyl)aziridine-2-carboxylate esters in the synthesis of biologically relevant compounds

• Iwona E. Głowacka,
• Aleksandra Trocha,
• Andrzej E. Wróblewski and
• Dorota G. Piotrowska

Beilstein J. Org. Chem. 2019, 15, 1722–1757, doi:10.3762/bjoc.15.168

• reagent to enantiomerically pure (R)-122 (Scheme 31) useful in pseudopeptide synthesis. Derivatives of nonproteinogenic ʟ-2,3-diaminopropanoic acid, e.g., (S)-125 were synthesized from the aziridine ester (2R,1'R)-5b employing the aluminum chloride catalyzed opening of the aziridine ring with azide

Different reactivity of phosphorylallenes under the action of Brønsted or Lewis acids: a crucial role of involvement of the P=O group in intra- or intermolecular interactions at the formation of cationic intermediates

• Stanislav V. Lozovskiy,
• Alexander Yu. Ivanov and
• Aleksander V. Vasilyev

Beilstein J. Org. Chem. 2019, 15, 1491–1504, doi:10.3762/bjoc.15.151

• intermolecular hydroarylation of allenes bearing electron-withdrawing substituents. Plausible reaction mechanisms have been proposed on the basis of the investigated reactions, and NMR analysis and DFT studies of the intermediate cationic species. Keywords: aluminum chloride; cation; intermediate

Synthesis of 1-indanones with a broad range of biological activity

• Marika Turek,
• Dorota Szczęsna,
• Marek Koprowski and
• Piotr Bałczewski

Beilstein J. Org. Chem. 2017, 13, 451–494, doi:10.3762/bjoc.13.48

• new method for the synthesis of pure indatraline ((−)-29) in a sequence of reactions starting from carboxylic acid 27 (Scheme 10). 1.1.2 From acid chlorides: The first synthesis of unsubstituted 1-indanone (2), obtained from the reaction of phenylpropionic acid chloride with aluminum chloride in

• using lithium, nickel and palladium catalysts (Scheme 15). A general mechanism illustrating the role of transition metal complexes and CO in this reaction is shown in Scheme 15. Cyclic esters were also used in the syntheses of 1-indanones. Thus, by adding β-propiolactone to aluminum chloride in benzene

• , 1-indanone has been obtained in 80% yield. Interestingly, when aluminum chloride was added to the lactone in benzene, the yield of this reaction decreased (30%) [34]. Irradiation of esters 44 possessing the photoremovable 2,5-dimethylphenacyl group in benzene or cyclohexane solutions led to free

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

TTFs nonsymmetrically fused with alkylthiophenic moieties

• Rafaela A. L. Silva,
• Bruno J. C. Vieira,
• Marta M. Andrade,
• Isabel C. Santos,
• Sandra Rabaça,
• Dulce Belo and
• Manuel Almeida

Beilstein J. Org. Chem. 2015, 11, 628–637, doi:10.3762/bjoc.11.71

• internal reference. UV–vis spectra were recorded on a UV-1800 Shimadzu spectrophotometer. Mass spectra were obtained in QIT/MS Bruker HCT by collision-induced dissociation (CID). 5-(tert-Butyl)thieno[2,3-d][1,3]dithiol-2-one (I): 0.536 g of aluminum chloride in 12 mL dichloromethane was cooled to −78 °C in

Selective methylation of kaempferol via benzylation and deacetylation of kaempferol acetates

• Qinggang Mei,
• Chun Wang,
• Weicheng Yuan and
• Guolin Zhang

Beilstein J. Org. Chem. 2015, 11, 288–293, doi:10.3762/bjoc.11.33

• result in heterocycle cleavage of the flavonoid skeleton. To obtain 3,7-di-O-methylkaempferol (7), we envisioned the possibility of methylation from the 4′-O-acetylkaempferol (6), which can be derived from 2. We were delighted that the combination of reflux with aluminum chloride in polar solvent CH3CN

On the bromination of the dihydroazulene/vinylheptafulvene photo-/thermoswitch

• Virginia Mazzanti,
• Martina Cacciarini,
• Søren L. Broman,
• Christian R. Parker,
• Magnus Schau-Magnussen,
• Andrew D. Bond and
• Mogens B. Nielsen

Beilstein J. Org. Chem. 2012, 8, 958–966, doi:10.3762/bjoc.8.108

• is hence a convenient building block for further functionalization. Moreover, we have found that the treatment of DHA by aluminum chloride followed by water provided another means of inducing ring-opening of DHA to form VHF (Scheme 1) [10]. This method is particularly convenient for making VHF on a

• Discussion Synthesis DHA 1 was first opened to VHF 2 by aluminum chloride followed by quenching with water according to a previously described procedure (Scheme 4) [10]. The resulting VHF 2 was then treated with NBS and benzoyl peroxide in benzene and the mixture was subjected to irradiation from a 500 W

• functionalizing the DHA/VHF photo-/thermoswitch with a bromo substituent at position 3 in the DHA core (product 8). The synthesis explores the ready conversion of DHA 1 to VHF 2 on a preparative scale by using aluminum chloride followed by NBS bromination. This bromination was found to occur selectively in the

Cyclization of 5-hexynoic acid to 3-alkoxy-2-cyclohexenones

• Anne T. Hylden,
• Eric J. Uzelac,
• Zeljko Ostojic,
• Ting-Ting Wu,
• Keely L. Sacry,
• Krista L. Sacry,
• Lin Xi and
• T. Nicholas Jones

Beilstein J. Org. Chem. 2011, 7, 1323–1326, doi:10.3762/bjoc.7.155

• -hexynoyl chloride (2) [10] under Lewis acid conditions and quenching of the reaction with ethanol (Table 1). Our first cyclization attempt utilized silver tetrafluoroborate, which was found to be ineffective at promoting the cyclization. Use of aluminum chloride led to cyclization, but in very modest yield

Novel carbazole–pyridine copolymers by an economical method: synthesis, spectroscopic and thermochemical studies

• Aamer Saeed,
• Madiha Irfan and
• Shahid Ameen Samra

Beilstein J. Org. Chem. 2011, 7, 638–647, doi:10.3762/bjoc.7.75

• of tetrabutylammonium bromide (TBAB) as a phase-transfer catalyst [23][24][25]. The N-alkylcarbazoles were subsequently subjected to Friedel–Crafts acetylation at the active positions of carbazole, viz. 3 and 6, with anhydrous aluminum chloride in dry chloroform [26]. The monomers were purified by

• were recorded under a nitrogen atmosphere at a heating rate of 10 °C/min. Elemental analyses were performed on CHNS 932 LECO instrument. Carbazole, 1-bromobutane, 1-bromooctane, tetrabutylammonium bromide (TBAB) and aluminum chloride were commercial products from Fluka; acetyl chloride, benzaldehydes

• : 85.8%, H: 8.9%, N: 5.0%. 3,6-Diacetyl-9-butylcarbazole (2a) Aluminum chloride, (4.0 g, 3 mmol) and acetyl chloride, (2.35 g, 3 mmol) were added successively to 10 mL of dry chloroform. The mixture was stirred for 10 min at 0 °C to obtain a clear solution. A solution of (4.46 g, 2 mmol) of 1a in 10 mL