Oxidation of benzylic alcohols to carbonyls using N-heterocyclic stabilized λ³-iodanes

• Thomas J. Kuczmera,
• Pim Puylaert and
• Boris J. Nachtsheim

Beilstein J. Org. Chem. 2024, 20, 1677–1683, doi:10.3762/bjoc.20.149

• of 87% and 64%, respectively. Unfortunately, the synthesis of vanillin (4q) was unsuccessful due to undesirable oxidation reactions of the electron-rich arene. The cyclopropane derivative 4r was generated from the cyclopropylmethanol in 53% yield. The acetylene derivative 4s could not be isolated due

Synthesis of 5-arylidenerhodanines in L-proline-based deep eutectic solvent

• Stéphanie Hesse

Beilstein J. Org. Chem. 2023, 19, 1537–1544, doi:10.3762/bjoc.19.110

• purification steps as a real environmentally benign synthetic process should as far as possible exclude organic solvents from all stages. In a first attempt, vanillin was reacted with rhodanine for 2 h at room temperature in Pro/Gly (1:2) and product 3a was obtained in 57% yield by a simple filtration after

Transition-metal-catalyzed domino reactions of strained bicyclic alkenes

• Austin Pounder,
• Eric Neufeld,
• Peter Myler and
• William Tam

Beilstein J. Org. Chem. 2023, 19, 487–540, doi:10.3762/bjoc.19.38

Preparation of β-cyclodextrin/polysaccharide foams using saponin

• Max Petitjean and
• José Ramón Isasi

Beilstein J. Org. Chem. 2023, 19, 78–88, doi:10.3762/bjoc.19.7

• matrices, the sorption of 4-ethylphenol and eugenol are the most favourable, followed by that of vanillin. Finally, the synthesis pathway (either liquid or foam) is not a determinant factor for the sorption capacity either. This fact can be explained by the similar microstructures produced in each case

• (Quillaja saponaria; Sp. ‘quillay’, from Mapuche ‘küllay’) saponin (Sigma-Aldrich, sapogenin content ≥ 10%, India), phenol (99.5%; Panreac, Spain), m-cresol (99%; Sigma, Germany), 4-ethylphenol (99%, Sigma, China), vanillin (99%; Panreac, Spain) and eugenol (99%; Sigma, Germany) were used as received

• -cyclodextrin/polysaccharides (blue curves for chitosan, red for locust bean gum, green for xanthan gum) with saponin (yellow curves correspond to cyclodextrin matrices, without polysaccharide). Sorption of phenols (V, vanillin; Ph, phenol; m-c, m-cresol; 4eP, 4-ethylphenol; Eu, eugenol) in β-cyclodextrin

Cyclodextrin-based Schiff base pro-fragrances: Synthesis and release studies

• Attila Palágyi,
• Jindřich Jindřich,
• Juraj Dian and
• Sophie Fourmentin

Beilstein J. Org. Chem. 2022, 18, 1346–1354, doi:10.3762/bjoc.18.140

• – cinnamaldehyde, cyclamen aldehyde, lilial, benzaldehyde, anisaldehyde, vanillin, hexanal, heptanal, citral, and 5-methylfurfural. Subsequently, the rate of release of the volatile compound from selected pro-fragrances, as a function of the environment (solvent, pH), was studied by 1H NMR spectroscopy (for

• -cinnamaldehyde (2a), cyclamen aldehyde (2b), lilial (2c), benzaldehyde (2d), anisaldehyde (2e), vanillin (2f), hexanal (2g), heptanal (2h), citral (2i), 5-methylfurfural (2j). The integrals of the imine group proton signal at 8.30 ppm in the acquired 1H NMR spectrum of compound 3d at pH 9 as a function of time

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

• ” (substantivity of many hours), or a “base note” (substantivity of days up to weeks) [2][20]. Typically, fresh and citric odorants, e.g., limonene, are top notes, while warm and sweet odorants such as vanillin are base notes [21]. However, these classical categories have been partially overcome by synthetic

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

Synthesis of legonmycins A and B, C(7a)-hydroxylated bacterial pyrrolizidines

• Wilfred J. M. Lewis,
• David M. Shaw and
• Jeremy Robertson

Beilstein J. Org. Chem. 2021, 17, 334–342, doi:10.3762/bjoc.17.31

• Geduran Si 60 silica gel as the stationary phase unless otherwise specified. “Brine” refers to sat. aq NaCl solution. Thin-layer chromatography (TLC) was performed with Merck TLC 60 Silica gel F254 plates as the stationary phase and spots were visualized with KMnO4, vanillin, anisaldehyde, or ultraviolet

A proposed sustainability index for synthesis plans based on input provenance and output fate: application to academic and industrial synthesis plans for vanillin as a case study

• John Andraos

Beilstein J. Org. Chem. 2020, 16, 2346–2362, doi:10.3762/bjoc.16.196

• of the target product that is actually used for its intended purpose. Renewable energy sources are defined as originating from hydroelectric, wind, solar, geothermal, and biomass sources. The computation of SI is illustrated for 22 synthesis plans of the high commodity flavour ingredient vanillin

• synthesis plans of the high commodity flavour ingredient vanillin. Methodology We begin the development of a quantitative description of sustainability applied to synthesis plans by starting with the mathematical statement of the law of mass balance given by Equation 1. where the M quantities refer to

• vanillin since this high commodity flavour chemical is ideally suited to the present investigation owing to its varied methods of synthesis spanning classical chemical synthesis, biofermentation, and solvent extraction procedures from the natural source vanilla beans. We chose these particular examples

Azidophosphonium salt-directed chemoselective synthesis of (E)/(Z)-cinnamyl-1H-triazoles and regiospecific access to bromomethylcoumarins from Morita–Baylis–Hillman adducts

• Soundararajan Karthikeyan,
• Radha Krishnan Shobana,
• Kamarajapurathu Raju Subimol,
• J. Helen Ratna Monica and
• Ayyanoth Karthik Krishna Kumar

Beilstein J. Org. Chem. 2020, 16, 1579–1587, doi:10.3762/bjoc.16.130

• ). The synthetic utility of the reaction was further extended to ortho-vanillin and para-bromobenzaldehyde to afford the corresponding halomethylcoumarins (4b/c). However, this regiospecific transformation was restricted only to the MBH adducts derived from salicyladehydes and tert-butyl acrylate [52][53

Efficient method for propargylation of aldehydes promoted by allenylboron compounds under microwave irradiation

• Jucleiton J. R. Freitas,
• Queila P. S. B. Freitas,
• Silvia R. C. P. Andrade,
• Juliano C. R. Freitas,
• Roberta A. Oliveira and
• Paulo H. Menezes

Beilstein J. Org. Chem. 2020, 16, 168–174, doi:10.3762/bjoc.16.19

• method was evaluated using aldehydes containing different functionalities. For example, the use of vanillin, an aldehyde containing the acidic phenol group as substituent, gave the corresponding product 2o in 93% yield in an 82:18 ratio of regioisomers. In the same way, when aldehydes containing an ester

Azologization and repurposing of a hetero-stilbene-based kinase inhibitor: towards the design of photoswitchable sirtuin inhibitors

• Christoph W. Grathwol,
• Nathalie Wössner,
• Sören Swyter,
• Adam C. Smith,
• Enrico Tapavicza,
• Robert K. Hofstetter,
• Anja Bodtke,
• Manfred Jung and
• Andreas Link

Beilstein J. Org. Chem. 2019, 15, 2170–2183, doi:10.3762/bjoc.15.214

• EtOH and 16 mL water) or vanillin/sulfuric acid (3.0 g vanillin and 0.5 mL H2SO4 in 100 mL EtOH) reagent. Synthesis was additionally monitored using high speed SFC/MS runs performed by a Nexera SFE-SFC/UHPLC switching system (Shimadzu Corporation, Kyoto, Japan) consisting of a pumping system (one LC

Lanyamycin, a macrolide antibiotic from Sorangium cellulosum, strain Soce 481 (Myxobacteria)

• Lucky S. Mulwa,
• Rolf Jansen,
• Dimas F. Praditya,
• Kathrin I. Mohr,
• Patrick W. Okanya,
• Joachim Wink,
• Eike Steinmann and
• Marc Stadler

Beilstein J. Org. Chem. 2018, 14, 1554–1562, doi:10.3762/bjoc.14.132

• dichloromethane/acetone (3:2) and turned dark brown on treatment with vanillin/H2SO4 reagent. RP-HPLC coupled to HRESIMS showed the two compounds were isomers with the elemental formula C45H63NO12, which was derived from the ion clusters [2M + Na]+, [M + Na]+, [M − H2O + H]+, [M − 2H2O + H]+, and [M − 3H2O + H

• procedures Analytical TLC: TLC aluminum sheets silica gel Si 60 F254 (Merck), detection by UV absorption at 254 nm and 366 nm. Spray reagent vanillin/sulfuric acid (prepared by dissolving vanillin (0.5 g) in 100 mL of sulfuric acid) followed by heating to about 120 °C on a hot plate. UV data were recorded on

An efficient synthesis of 1,6-anhydro-N-acetylmuramic acid from N-acetylglucosamine

• Matthew B. Calvert,
• Christoph Mayer and
• Alexander Titz

Beilstein J. Org. Chem. 2017, 13, 2631–2636, doi:10.3762/bjoc.13.261

• N-acetylglucosamine. Experimental General details Silica gel 60-coated aluminum sheets containing fluorescence indicator (Macherey-Nagel, Düren, Germany) were used for thin-layer chromatography (TLC). UV light (254 nm) and vanillin solution (0.4 M solution of vanillin in 1% ethanolic H2SO4) or

Curcuminoid–BF₂ complexes: Synthesis, fluorescence and optimization of BF₂ group cleavage

• Henning Weiss,
• Jeannine Reichel,
• Helmar Görls,
• Kilian Rolf Anton Schneider,
• Mathias Micheel,
• Michael Pröhl,
• Michael Gottschaldt,
• Benjamin Dietzek and
• Wolfgang Weigand

Beilstein J. Org. Chem. 2017, 13, 2264–2272, doi:10.3762/bjoc.13.223

• ]. Boric acid esters like tri-n-butyl borate are normally used to scavenge water being produced during the reaction, while piperidine [9] and n-butylamine [10][11] are typical bases used as catalysts for this type of reaction (Scheme 1). Although working well with vanillin and similar derivatives, the

The effect of milling frequency on a mechanochemical organic reaction monitored by in situ Raman spectroscopy

• Patrick A. Julien,
• Ivani Malvestiti and
• Tomislav Friščić

Beilstein J. Org. Chem. 2017, 13, 2160–2168, doi:10.3762/bjoc.13.216

• of reactive encounters between the particles. In contrast, ex situ gas chromatography studies of the Knoevenagel condensation between vanillin and barbituric acid in a planetary mill revealed a sigmoidal dependence of reaction yield with time [22]. Similarly, sigmoidal dynamics were detected by in

New bio-nanocomposites based on iron oxides and polysaccharides applied to oxidation and alkylation reactions

• Daily Rodríguez-Padrón,
• Alina M. Balu,
• Antonio A. Romero and
• Rafael Luque

Beilstein J. Org. Chem. 2017, 13, 1982–1993, doi:10.3762/bjoc.13.194

• substituted benzyl alcohols. Although benzyl alcohol is industrially produced by reduction of benzaldehyde, this aldehyde is considered as the second most important flavoring molecule after vanillin, due to its variety of applications in cosmetics, perfumes, food, dyes, agrochemicals and pharmaceuticals [41

Solvent-free sonochemistry: Sonochemical organic synthesis in the absence of a liquid medium

• Deborah E. Crawford

Beilstein J. Org. Chem. 2017, 13, 1850–1856, doi:10.3762/bjoc.13.179

• sonochemical reactions being carried out in the absence of solvent, or a liquid reagent [8][9]. Herein, we report two condensation reactions (investigated extensively by ball milling), one to form salen ligand 1 by sonicating o-vanillin and 1,2-phenylenediamine, and the second to form 1,3-indandione 2 from

• mechanical energy (and may undergo degradation) may be successful by ultrasonic irradiation. It must be noted that the conventional reaction between o-vanillin and 1,2-phenylenediamine requires refluxing for 9 hours in ethanol for a complete conversion to the product. For the initial sonochemistry

• experiments (Scheme 1), both reagents were used as received, o-vanillin came in the form of small flakes and 1,2-phenylenediamine was received as large crystalline beads (Figure 2). Upon sonication of the mixed reagents (using a standard ultrasonication bath with a frequency of 35 kHz) for 60 minutes, it was

Mechanochemical synthesis of graphene oxide-supported transition metal catalysts for the oxidation of isoeugenol to vanillin

• Ana Franco,
• Sudipta De,
• Alina M. Balu,
• Araceli Garcia and
• Rafael Luque

Beilstein J. Org. Chem. 2017, 13, 1439–1445, doi:10.3762/bjoc.13.141

• Singapore, 4 Engineering Drive 4, 117585, Singapore 10.3762/bjoc.13.141 Abstract Vanillin is one of the most commonly used natural products, which can also be produced from lignin-derived feedstocks. The chemical synthesis of vanillin is well-established in large-scale production from petrochemical-based

• starting materials. To overcome this problem, lignin-derived monomers (such as eugenol, isoeugenol, ferulic acid etc.) have been effectively used in the past few years. However, selective and efficient production of vanillin from these feedstocks still remains an issue to replace the existing process. In

• this work, new transition metal-based catalysts were proposed to investigate their efficiency in vanillin production. Reduced graphene oxide supported Fe and Co catalysts showed high conversion of isoeugenol under mild reaction conditions using H2O2 as oxidizing agent. Fe catalysts were more selective

Ultrasound-promoted organocatalytic enamine–azide [3 + 2] cycloaddition reactions for the synthesis of ((arylselanyl)phenyl-1H-1,2,3-triazol-4-yl)ketones

• Gabriel P. Costa,
• Natália Seus,
• Juliano A. Roehrs,
• Raquel G. Jacob,
• Ricardo F. Schumacher,
• Thiago Barcellos,
• Rafael Luque and
• Diego Alves

Beilstein J. Org. Chem. 2017, 13, 694–702, doi:10.3762/bjoc.13.68

• selanyltriazoyl carboxylates, with carboxamides and carbonitriles synthesized in high yields and short times of reaction. Experimental General information The reactions were monitored by TLC carried out on Merck silica gel (60 F254) by using UV light as visualizing agent and 5% vanillin in 10% H2SO4 and heat as

Effect of the ortho-hydroxy group of salicylaldehyde in the A³ coupling reaction: A metal-catalyst-free synthesis of propargylamine

• Sujit Ghosh,
• Kinkar Biswas,
• Suchandra Bhattacharya,
• Pranab Ghosh and
• Basudeb Basu

Beilstein J. Org. Chem. 2017, 13, 552–557, doi:10.3762/bjoc.13.53

• propargylamine (the A3 coupled product) in 82–90% isolated yields (Figure 1, 3a–j). Substituted salicylaldehyde like 3,5-dibromosalicylaldehyde or o-vanillin also reacted easily when treated with morpholine and phenylacetylene, p-tolylacetylene or o- and p-bromophenylacetylene as the other coupling components at

Rearrangements of organic peroxides and related processes

• Ivan A. Yaremenko,
• Vera A. Vil’,
• Dmitry V. Demchuk and
• Alexander O. Terent’ev

Beilstein J. Org. Chem. 2016, 12, 1647–1748, doi:10.3762/bjoc.12.162

Three new trixane glycosides obtained from the leaves of Jungia sellowii Less. using centrifugal partition chromatography

• Luíse Azevedo,
• Larissa Faqueti,
• Marina Kritsanida,
• Antonia Efstathiou,
• Despina Smirlis,
• Gilberto C. Franchi Jr,
• Grégory Genta-Jouve,
• Sylvie Michel,
• Louis P. Sandjo,
• Raphaël Grougnet and
• Maique W. Biavatti

Beilstein J. Org. Chem. 2016, 12, 674–683, doi:10.3762/bjoc.12.68

• spraying with sulfuric vanillin solution at 30% and heating. The mobile phase used to monitor the method development and the fractions was composed by EtOAc/CH2O2/AcOH/H2O (60:0.6:0.6:20). The 1D and 2D NMR experiments were recorded with Bruker AC-300 and Bruker Avance-400 spectrometers at 400 MHz for 1H

Highly selective generation of vanillin by anodic degradation of lignin: a combined approach of electrochemistry and product isolation by adsorption

• Dominik Schmitt,
• Carolin Regenbrecht,
• Marius Hartmer,
• Florian Stecker and
• Siegfried R. Waldvogel

Beilstein J. Org. Chem. 2015, 11, 473–480, doi:10.3762/bjoc.11.53

• degradation of lignin into a variety of valuable products has been under investigation since the first half of the last century. Especially, the chance to claim this cheap, abundant and renewable source for the production of the important aroma chemical vanillin (1) was one of the major driving forces of

• vanillin (1), acetovanillone (2) and guaiacol (3) (Scheme 1) [8][9][10]. Different approaches for selective degradation of lignin, applying catalytic, microbacterial, photochemical, sono-chemical and electrochemical methods were investigated but struggled with several problems [11][12][13][14][15][16][17

• ]. Consequently, such conversions are considered as reagent-free and avoid reagent waste [28][29][30]. We present a highly selective electrochemical approach providing an almost exclusive formation of vanillin (1) under very mild reaction conditions. The application of a strongly basic anion exchange resin allows

Natural phenolic metabolites with anti-angiogenic properties – a review from the chemical point of view

• Qiu Sun,
• Jörg Heilmann and
• Burkhard König

Beilstein J. Org. Chem. 2015, 11, 249–264, doi:10.3762/bjoc.11.28

• formation of a complex with boric oxide, followed by reaction with vanillin. Instead of boric oxide, alkyl borates and boric acid can also be used. The first attempt at modification was to truncate the general structure to either a single enone or dienone system. The latter structure contained a

• ) vanillin, 1,2,3,4-tetrahydroquinoline, HOAc, H3BO3, DMF, Δ, 4 h. Exemplary synthesis of MAC representatives. Reagents and conditions: (a) 40% KOH, EtOH, 5 °C; stirring 10 h, rt. X = C, N; R = OH, OMe, Cl, F. Synthesis of ellagic acid (7). Reagents and conditions: (a) H2SO4, CH3OH; (b) (1) o-chloranil, Et2O