Benzylic C(sp³)–H fluorination

• Alexander P. Atkins,
• Alice C. Dean and
• Alastair J. J. Lennox

Beilstein J. Org. Chem. 2024, 20, 1527–1547, doi:10.3762/bjoc.20.137

• the ionic liquid 1-ethyl-3-methylimidazolium trifluoromethanesulfonate ([emim][OTf]) for the fluorination of phthalides at the benzylic position (Figure 37) [95]. It was considered that the zwitterionic nature of the ionic liquid served two purposes. Firstly, to enhance the nucleophilicity of fluoride

Synthetic applications of the Cannizzaro reaction

• Bhaskar Chatterjee,
• Dhananjoy Mondal and
• Smritilekha Bera

Beilstein J. Org. Chem. 2024, 20, 1376–1395, doi:10.3762/bjoc.20.120

• phthalides 100, as evidenced by the per-O-methylated derivative of pestalone, a marine natural substance. Either in a Cannizarro–Tishchenko-type reaction with nucleophile catalysis (NaCN) or under photochemical conditions (DMSO, 350 nm), the transformation often proceeds without any problems in DMSO (Scheme

• Cannizzaro reaction. Microwave-assisted crossed-Cannizzaro reaction for the synthesis of 3,3-disubstituted oxindoles. Synthesis of porphyrin-based rings using the Cannizzaro reaction. Synthesis of phthalides and pestalalactone via Cannizarro–Tishchenko-type reaction. Synthesis of dibenzoheptalene bislactones

Enantioselective synthesis of β-aryl-γ-lactam derivatives via Heck–Matsuda desymmetrization of N-protected 2,5-dihydro-1H-pyrroles

• Arnaldo G. de Oliveira Jr.,
• Martí F. Wang,
• Rafaela C. Carmona,
• Danilo M. Lustosa,
• Sergei A. Gorbatov and
• Carlos R. D. Correia

Beilstein J. Org. Chem. 2024, 20, 940–949, doi:10.3762/bjoc.20.84

• , key five-membered olefins bearing heteroatoms can provide direct access to chiral sulfones, sulfoxides, phosphine oxides [8], phthalides, isochromanones, and lactones [9] in a very efficient and convenient manner. Despite our previous results in this area, the desymmetrization of 2,5-dihydro-1H

Electroreductive coupling of 2-acylbenzoates with α,β-unsaturated carbonyl compounds: density functional theory study on product selectivity

• Naoki Kise and
• Toshihiko Sakurai

Beilstein J. Org. Chem. 2022, 18, 956–962, doi:10.3762/bjoc.18.95

• and successive treatment with 1 M HCl gave 2-cyanonaphthalen-1-ols or 3-(3-cyanoethyl)phthalides. On the other hand, the reaction of 2-acylbenzoates with methyl vinyl ketone under the same conditions produced 3-(3-oxobutyl)phthalides as the sole products. What determines the product selectivity was

• studied using DFT calculations. Keywords: 2-acylbenzoates; chlorotrimethylsilane; 3-(3-cyanoethyl)phthalides; 2-cyanonaphthalen-1-ols; electroductive coupling; Introduction The electroreductive coupling between carbon–heteroatom and carbon–carbon double bonds is one of the promising methods for carbon

• context, we report here that the electroreduction of o-acylbenzoates 1 with acrylonitrile (2a) in the presence of TMSCl and subsequent treatment with 1 M HCl gives 2-cyanonaphthalen-1-ols 3 or 3-(3-cyanoethyl)phthalides 4 (Scheme 3). The product selectivity depends on the position of the methoxy

Icilio Guareschi and his amazing “1897 reaction”

• Gian Cesare Tron,
• Alberto Minassi,
• Giovanni Sorba,
• Mara Fausone and
• Giovanni Appendino

Beilstein J. Org. Chem. 2021, 17, 1335–1351, doi:10.3762/bjoc.17.93

• studies on naphthalene and the conversion of naphthalene to phthalides, a reaction that, two decades later, became of critical relevance for the industrial synthesis of indigo. It is surprising that, after spending only three years in Siena, Guareschi obtained, in 1879, the prestigious Chair of Medicinal

Nucleophilic fluoroalkylation/cyclization route to fluorinated phthalides

• Masanori Inaba,
• Tatsuya Sakai,
• Shun Shinada,
• Tsuyuka Sugiishi,
• Yuta Nishina,
• Norio Shibata and
• Hideki Amii

Beilstein J. Org. Chem. 2018, 14, 182–186, doi:10.3762/bjoc.14.12

• practical method for the synthesis of C3-perfluoroalkyl-substituted phthalides in a one-pot manner. Upon treatment of KF or triethylamine, 2-cyanobenzaldehyde reacted with (perfluoroalkyl)trimethylsilanes via nucleophilic addition and subsequent intramolecular cyclization to give perfluoroalkylphthalides in

• good yields. Keywords: cyclization; fluorine; lactone; phthalide; trifluoromethylation; Introduction Phthalides (1(3H)-isobenzofuranones) are frequently found in natural products and exhibit a range of bioactivity (Scheme 1) [1][2]. Substituted phthalides have been used as building blocks for the

• synthesis of useful bioactive compounds. There is a growing interest in the usefulness of phthalides and their derivatives. Organofluorine compounds often show attractive physical, chemical, and biological properties and are widely used in many fields, such as pharmaceuticals, agrochemicals, and materials

Sustainable synthesis of 3-substituted phthalides via a catalytic one-pot cascade strategy from 2-formylbenzoic acid with β-keto acids in glycerol

• Lina Jia and
• Fuzhong Han

Beilstein J. Org. Chem. 2017, 13, 1425–1429, doi:10.3762/bjoc.13.139

• Lina Jia Fuzhong Han College of Chemistry and Chemical Engineering, Qiqihar University, Qiqihar 161006, China 10.3762/bjoc.13.139 Abstract Background: Phthalides are privileged constituents of numerous pharmaceuticals, natural products and agrochemicals and exhibit several biological and

• phthalides in good to excellent yields. Conclusion: A concise and efficient synthesis strategy of 3-substituted phthalides from 2-formylbenzoic acid and β-keto acids via a catalytic one-pot cascade reaction in glycerol has been accomplished. Keywords: β-keto acid; decarboxylation; glycerol; one-pot cascade

• reaction; phthalide; Introduction The phthalides, also known as isobenzofuran-1(3H)-ones, are an important class of heterocycles which are of continued interest for chemists [1][2]. 3-Substituted phthalides, which are recognized as versatile building blocks found in a large number of bioactive compounds

Marilones A–C, phthalides from the sponge-derived fungus Stachylidium sp.

• Celso Almeida,
• Stefan Kehraus,
• Miguel Prudêncio and
• Gabriele M. König

Beilstein J. Org. Chem. 2011, 7, 1636–1642, doi:10.3762/bjoc.7.192

• B (2) showed selective antagonistic activity towards the serotonin receptor 5-HT2B with a Ki value of 7.7 µM. Keywords: marine fungi; natural products; phthalides; polyketides; Introduction Phthalides are a class of structurally very diverse secondary metabolites with more than 180 naturally

• occurring compounds described [1]. They are produced by a wide range of organisms, i.e., by marine and terrestrial fungi belonging to genera such as Ascochyta [2], Aspergillus [3][4][5], Alternaria [6], Penicillium [7], Hericium [8] or Talaromyces [9], but also by plants and liverworts [1]. Phthalides

• known natural product nidulol was formed [6]. To further prove that the carbonyl group is positioned at C-1 and not at C-8 of 1, 1H NMR spectra of 1 were compared with those of nidulol and silvaticol (4) (and derivatives, see Supporting Information File 1). The latter are known regioisomeric phthalides