Computational toolbox for the analysis of protein–glycan interactions

• Ferran Nieto-Fabregat,
• Maria Pia Lenza,
• Angela Marseglia,
• Cristina Di Carluccio,
• Antonio Molinaro,
• Alba Silipo and
• Roberta Marchetti

Beilstein J. Org. Chem. 2024, 20, 2084–2107, doi:10.3762/bjoc.20.180

• interaction with host proteins [5][6]. Notably, the complexity of the glycome far surpasses that of the genome, transcriptome, and proteome, not only due to the structural and conformational diversity of glycans, whose synthesis is not template driven, but also due to their dynamic nature [5][6]. Although

Multicomponent syntheses of pyrazoles via (3 + 2)-cyclocondensation and (3 + 2)-cycloaddition key steps

• Ignaz Betcke,
• Alissa C. Götzinger,
• Maryna M. Kornet and
• Thomas J. J. Müller

Beilstein J. Org. Chem. 2024, 20, 2024–2077, doi:10.3762/bjoc.20.178

• ], pyrazoles also find applications in OLED technology [20] and optical brighteners [21] in the textile and laundry industry. The ongoing quest for novel, potent, and efficient syntheses of pyrazoles prompts the search for the “ideal” synthesis [22][23], one that addresses all the synthetic challenges to meet

• the ecological and economic requirements. This “ideal” synthesis would commence with simple starting materials, progress through safe, catalytic, and quantitative conversions, and culminate in streamlined processes, all conducted within a single reaction vessel. Multicomponent reactions (MCR) closely

• concatenation of organic elementary steps in a one-pot fashion. Many reviews on general syntheses of pyrazoles have been published [25][26][27][28][29][30][31][32][33][34][35][36][37][38], as well as a few dedicated reviews on MCR synthesis of pyrazole derivatives [39][40][41]. In sensu stricto, multicomponent

Diastereoselective synthesis of highly substituted cyclohexanones and tetrahydrochromene-4-ones via conjugate addition of curcumins to arylidenemalonates

• Deepa Nair,
• Abhishek Tiwari,
• Banamali Laha and
• Irishi N. N. Namboothiri

Beilstein J. Org. Chem. 2024, 20, 2016–2023, doi:10.3762/bjoc.20.177

• Deepa Nair Abhishek Tiwari Banamali Laha Irishi N. N. Namboothiri Department of Chemistry, Indian Institute of Technology Bombay, Mumbai, 400 076, India 10.3762/bjoc.20.177 Abstract A cascade inter–intramolecular double Michael strategy for the synthesis of highly functionalized cyclohexanones

• in most cases. A triple Michael adduct, tetrahydrochromen-4-one, is also formed as a side product in a few cases with excellent diastereoselectivity. Keywords: arylidenemalonates; curcumins; cyclohexanones; diastereoselective synthesis; Michael reaction; tetrahydrochromenones; Introduction There is

• considerable interest in the stereoselective synthesis of the cyclohexanone skeleton as it constitutes the core structure in many natural products and pharmaceutical drugs [1][2]. Garsubellin A with a cyclohexanone skeleton is a potent inducer of choline acetyltransferase (ChAT) and could be used for the

Harnessing the versatility of hydrazones through electrosynthetic oxidative transformations

• Aurélie Claraz

Beilstein J. Org. Chem. 2024, 20, 1988–2004, doi:10.3762/bjoc.20.175

• Aurelie Claraz Institut de Chimie des Substances Naturelles, CNRS, Univ. Paris-Saclay, 1 Avenue de la Terrasse, 91198 Gif-sur-Yvette Cedex, France 10.3762/bjoc.20.175 Abstract Hydrazones are important structural motifs in organic synthesis, providing a useful molecular platform for the

• versatile reagents in organic synthesis. They have for instance been frequently employed for the construction of azacycles through various cyclization protocols or cycloaddition reactions [6][7][8][9][10]. Early work in this field includes the well-known Fischer indole synthesis [11]. Additionally, they

• have been harnessed as valuable intermediates in Wolff–Kishner reduction reactions [12][13][14] or for the synthesis of various olefins via diazo or vinyllithium intermediates in the Bamford–Stevens reaction [15] and Shapiro reaction [16], respectively [17]. SAMP/RAMP ((S)/(R)-1-amino-2

Development of a flow photochemical process for a π-Lewis acidic metal-catalyzed cyclization/radical addition sequence: in situ-generated 2-benzopyrylium as photoredox catalyst and reactive intermediate

• Masahiro Terada,
• Zen Iwasaki,
• Ryohei Yazaki,
• Shigenobu Umemiya and
• Jun Kikuchi

Beilstein J. Org. Chem. 2024, 20, 1973–1980, doi:10.3762/bjoc.20.173

• , experimental procedures, and characterization data. Supporting Information File 30: Copies of NMR spectra. Funding This work was partially supported by a Grant-in-Aid for Scientific Research on Innovative Areas “Hybrid Catalysis for Enabling Molecular Synthesis on Demand” (JP17H06447) and a Grant-in-Aid for

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

• Liubov V. Sokolenko Taras M. Sokolenko Yurii L. Yagupolskii Institute of Organic Chemistry, National Academy of Sciences of Ukraine, Academician Kukhar str., 5, Kyiv-94, 02660, Ukraine 10.3762/bjoc.20.171 Abstract This article provides a comprehensive overview of the synthesis and chemistry of

• ; refrigerants; Introduction In the 1930s, halogenated chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs) were synthesized and have been shown to have low toxicity, which has opened the door for the application as safe refrigerants [1][2]. The development of the commercial synthesis of CFCs and

• are discussed in this Review article. Special attention is given to the role of 1,2-difluoroethylene in multiple reaction types. Review Preparation of HFO-1132 In scientific literature, the number of publications on the synthesis of 1,2-difluoroethylene is limited. HFO-1132 was first obtained in 1955

Regioselective alkylation of a versatile indazole: Electrophile scope and mechanistic insights from density functional theory calculations

• Pengcheng Lu,
• Luis Juarez,
• Paul A. Wiget,
• Weihe Zhang,
• Krishnan Raman and
• Pravin L. Kotian

Beilstein J. Org. Chem. 2024, 20, 1940–1954, doi:10.3762/bjoc.20.170

• spectra were acquired on Bruker 300 MHz spectrometers equipped with 5 mm BBFO probes. HRMS data were acquired using an Agilent 6530 LC/Q-TOF using a Dual AJS/ESI ion source, and the isotope 79 was used for HRMS analysis for any bromine-containing compounds. Synthesis All procedures and spectra can be

• and N2 transition states with favorable NCIs shown as red dashed lines. DFT-calculated transition-state structures and energies of 21 under conditions A (top) and conditions B (bottom). NMR, NOE, and yield data of compounds 8 and 9. Synthesis of compounds P1 and P2. Reaction of 21 under conditions A

• The synthesis efforts discussed in this paper were critically enabled by the support of a diverse set of talented teams, functional leaders, and highly motivated scientists, without whom this work would not have been possible. We would like to thank Dr. Liliana Gallegos for help with quantum mechanics

A new platform for the synthesis of diketopyrrolopyrrole derivatives via nucleophilic aromatic substitution reactions

• Vitor A. S. Almodovar and
• Augusto C. Tomé

Beilstein J. Org. Chem. 2024, 20, 1933–1939, doi:10.3762/bjoc.20.169

• synthesis of highly fluorescent DPP derivatives through straightforward nucleophilic aromatic substitution reactions with thiols and phenols. These nucleophilic substitutions occur at room temperature and manifest a remarkable selectivity for the 4-position of the pentafluorophenyl groups. Both symmetrical

• . Additionally, it is crucial to highlight the chemical versatility of compound 2, which allows the attachment of various functional units without significantly altering its optical properties. This versatility holds significant promise in the design and synthesis of innovative molecules tailored for specific

• Micromass Q-TOF-2TM mass spectrometer and CHCl3 as the solvent. The NMR, absorption and emission spectra of the new compounds are shown in Supporting Information File 1. Synthesis 3,6-Bis(4-chlorophenyl)-2,5-bis(pentafluorobenzyl)-2,5-dihydropyrrolo[3,4-c]pyrrole-1,4-dione (2) A suspension of DPP 1 (1 g

Negishi-coupling-enabled synthesis of α-heteroaryl-α-amino acid building blocks for DNA-encoded chemical library applications

• Matteo Gasparetto,
• Balázs Fődi and
• Gellért Sipos

Beilstein J. Org. Chem. 2024, 20, 1922–1932, doi:10.3762/bjoc.20.168

• crucial function in many biological processes. Due to their bifunctional character, they have been also used for combinatorial chemistry purposes, such as the preparation of DNA-encoded chemical libraries. We developed a practical synthesis for α-heteroaryl-α-amino acids starting from an array of small

• ]. The success of this technology ultimately relies on the quality and diversity of the libraries. DEL synthesis must employ DNA-compatible reactions; hence it operates under a limited set of conditions [4][5]. DELs are typically produced via split-and-pool combinatorial chemistry methods. Using

• -amino acids as primary diversity elements [10]. The pursuit of achieving the efficient synthesis of α-amino acids has been an ongoing challenge since 1850, marked by the initial report of the Strecker condensation [11]. The Strecker synthesis and the related Bucherer−Bergs hydantoin formation remains

Solvent-dependent chemoselective synthesis of different isoquinolinones mediated by the hypervalent iodine(III) reagent PISA

• Ze-Nan Hu,
• Yan-Hui Wang,
• Jia-Bing Wu,
• Ze Chen,
• Dou Hong and
• Chi Zhang

Beilstein J. Org. Chem. 2024, 20, 1914–1921, doi:10.3762/bjoc.20.167

• is an important heterocyclic framework in natural products and biologically active molecules, and the efficient synthesis of this structural motif has received much attention in recent years. Herein, we report a (phenyliodonio)sulfamate (PISA)-mediated, solvent-dependent synthesis of different

• Medicus (Figure 1) [9]. Therefore, in recent years, isoquinolinone derivatives have attracted considerable attention, and successful synthetic methods involving the isoquinolinone framework have been reported. A number of appealing methods for the synthesis of isoquinolinone scaffolds using transition

• metal reagents, including cobalt [10], copper [11], rhodium [12][13][14], palladium [15][16][17], silver [18], and gold [19] catalysts, have been reported. However, compared to the widespread use of metal catalysts, the synthesis of isoquinolinone scaffolds mediated by environmentally friendly

Novel oxidative routes to N-arylpyridoindazolium salts

• Oleg A. Levitskiy,
• Yuri K. Grishin and
• Tatiana V. Magdesieva

Beilstein J. Org. Chem. 2024, 20, 1906–1913, doi:10.3762/bjoc.20.166

• -pyridine substituted diarylamines, either using bis(trifluoroacetoxy)iodobenzene as an oxidant, or electrochemically, via potentiostatic oxidation. Electrochemical synthesis occurs under mild conditions; no chemical reagents are required except electric current. Both approaches can be considered as a late

• organic synthesis. In the present paper, convenient, easily reproducible, straightforward synthetic routes to N-arylpyridoindazolium salts were elaborated, based on both electrochemical and chemical (using bis(trifluoroacetoxy)iodobenzene, PIFA) oxidation of the ortho-pyridine-substituted diarylamines

• amine oxidation is increased. Electrochemical synthesis of pyridoindazolium salts The results of the voltammetry testing allowed to assume that pyridoindazolium salts can also be obtained using an anodic synthesis. Electric current as a reagent is inherently safe and easily scalable; electrosynthesis is

Access to 2-oxoazetidine-3-carboxylic acid derivatives via thermal microwave-assisted Wolff rearrangement of 3-diazotetramic acids in the presence of nucleophiles

• Ivan Lyutin,
• Vasilisa Krivovicheva,
• Grigory Kantin and
• Dmitry Dar’in

Beilstein J. Org. Chem. 2024, 20, 1894–1899, doi:10.3762/bjoc.20.164

• of the synthesis would be of great demand. We proposed that, besides modifying the 2-oxoazetidine-3-carboxylic acids themselves, such an approach could involve diazotetramic acids, subjected to thermal Wolff rearrangement, with various nucleophiles. The application of the Wolff rearrangement in

• organic synthesis as a route to generate ketenes is being actively investigated, involving both acyclic and carbocyclic diazocarbonyl compounds [26]. At the same time, the use of diazoheterocyclic reagents (including diazotetramic acids) in this transformation, with the formation of heterocyclic ring

• derivative 3a could be obtained in high yield (83%) after simple chromatographic separation of the reaction mixture (Scheme 2). When the synthesis was carried out using conventional heating in 1,2-dichlorobenzene (200 °C, 1 h), product 3a was obtained in slightly lower yield (75%), so further experiments

2-Heteroarylethylamines in medicinal chemistry: a review of 2-phenethylamine satellite chemical space

• Carlos Nieto,
• Alejandro Manchado,
• Ángel García-González,
• David Díez and
• Narciso M. Garrido

Beilstein J. Org. Chem. 2024, 20, 1880–1893, doi:10.3762/bjoc.20.163

• importance and applications of ring-modified histidines, Sharma et al. [66] reviewed the design, synthesis, and medicinal chemistry of these motifs covering antimicrobial, antiplasmodial, CNS and anticancer applications among others. Pyrazoles: Betazole (95) is a pyrazole-like histamine analogue with H2

The Groebke–Blackburn–Bienaymé reaction in its maturity: innovation and improvements since its 21st birthday (2019–2023)

• Cristina Martini,
• Muhammad Idham Darussalam Mardjan and
• Andrea Basso

Beilstein J. Org. Chem. 2024, 20, 1839–1879, doi:10.3762/bjoc.20.162

• synthesis (DOS) where a single methodology should generate diverse scaffolds. This comprehensive review focuses on all these aspects, and has been divided into five chapters, describing, respectively: a) efforts to develop new and milder reaction conditions; b) the use of new building blocks; c) the

• replaced tert-butyl isocyanide, Gd(OTf)3 was superior to La(OTf)3, and again performed similarly to Sc(OTf)3 (Scheme 2). With these results in hand, Longo et al. evaluated the scope and limitations of this lanthanide, obtaining good to excellent results in the synthesis of 23 different GBB adducts, using

• . Brunschweiger et al. employed the compartmentation strategy to overcome synthetic problems related to the preparation of a DNA-encoded GBB library [17]. DNA-encoded libraries (DELs) are widely used in screening projects, allowing the synthesis of a huge number of compounds as pools, and the identification of

A facile three-component route to powerful 5-aryldeazaalloxazine photocatalysts

• Ivana Weisheitelová,
• Radek Cibulka,
• Marek Sikorski and
• Tetiana Pavlovska

Beilstein J. Org. Chem. 2024, 20, 1831–1838, doi:10.3762/bjoc.20.161

• has been successfully applied as photoredox catalyst in the synthesis of secondary or primary anilines via light-dependent desulfonylation or desulfonylation/dealkylation procedures [19]. Thus, the design of novel and efficient routes for the synthesis of 5-aryldeazaalloxazines 2 has become a

• significant topic. Surprisingly, there has been limited information on 5-deazaalloxazines (dAll) synthesis [20][21][22]. Most known methods employ the cyclization of 6-(arylamino)uracils with one-carbon reagents such as triethyl orthoformate, dimethylformamide dimethylacetal, carbon disulfide, N,N

• continuation of our work on the synthesis of powerful photoredox flavins [14][15][16][17][18][19], we developed an efficient, general, one-pot domino method for the synthesis of a series of novel 5-aryldeazaalloxazines 2 from readily available substrates via a three-component fashion (Figure 1C). Results and

Chiral bifunctional sulfide-catalyzed enantioselective bromolactonizations of α- and β-substituted 5-hexenoic acids

• Sao Sumida,
• Ken Okuno,
• Taiki Mori,
• Yasuaki Furuya and
• Seiji Shirakawa

Beilstein J. Org. Chem. 2024, 20, 1794–1799, doi:10.3762/bjoc.20.158

• to asymmetric halolactonizations, especially for the synthesis of chiral γ-butyrolactones and δ-valerolactones via the reaction of 4-pentenoic acid and 5-hexenoic acid derivatives (Scheme 1). Notably, however, substituents on the carbon–carbon double bond of alkenoic acid substrates are generally

• remained a formidable challenge in the field of catalytic asymmetric synthesis (Scheme 1b) [23][24][25]. To address this limitation, we have investigated the use of BINOL-derived chiral bifunctional sulfide catalysts, which were developed by our group [10], in asymmetric bromolactonizations of α

• bifunctional sulfide (S)-1 [26][27][28][29][30][31]. To further demonstrate the utility of our chiral bifunctional sulfide catalysts in challenging halolactonizations, we next turned our attention to the asymmetric bromolactonizations of 5-hexenoic acid derivatives 2 for the synthesis of optically active δ

Oxidative fluorination with Selectfluor: A convenient procedure for preparing hypervalent iodine(V) fluorides

• Samuel M. G. Dearman,
• Xiang Li,
• Yang Li,
• Kuldip Singh and
• Alison M. Stuart

Beilstein J. Org. Chem. 2024, 20, 1785–1793, doi:10.3762/bjoc.20.157

• them easily because they normally require harsh fluorinating reagents. The synthesis of hypervalent iodine(V) fluoride 3 was reported by Amey and Martin in 1979 using the highly toxic gas, trifluoromethyl hypofluorite (Scheme 2A), and they later prepared bicyclic hypervalent iodine(V) fluoride 4 using

• formed an analogue of Amey and Martin’s monocyclic trifluoroiodane 3. Preparation of monocyclic trifluoro(aryl)-λ5-iodanes Our investigation into the synthesis of monocyclic trifluoro(aryl)-λ5-iodanes began with the preparation of the key iodine(III) precursors for our oxidative fluorination protocol

• . Fluoroiodane 2 was already available in our laboratory [11] and the three-step synthesis of methyl(trifluoromethyl)fluoroiodane 15 is shown in Scheme 4. The first step was a diazotisation of 2’-aminoacetophenone 12 to form 2’-iodoacetophenone 13, which was then reacted with Ruppert’s reagent (CF3SiMe3) to

Ugi bisamides based on pyrrolyl-β-chlorovinylaldehyde and their unusual transformations

• Alexander V. Tsygankov,
• Vladyslav O. Vereshchak,
• Tetiana O. Savluk,
• Serhiy M. Desenko,
• Valeriia V. Ananieva,
• Oleksandr V. Buravov,
• Yana I. Sakhno,
• Svitlana V. Shishkina and
• Valentyn A. Chebanov

Beilstein J. Org. Chem. 2024, 20, 1773–1784, doi:10.3762/bjoc.20.156

• compounds [1][2][3][4][5][6] to expand and systematically explore the chemical space within the concepts of molecular diversity chemistry (diversity oriented synthesis) [6] and biologically oriented synthesis [7]. Among the multicomponent processes, the four-component Ugi reaction (Ugi-4CR) [8][9][10][11

• ][12][13] is characterized by the greatest versatility, through the variability of the starting components leading to a variety of possible products [12][13][14][15][16][17]. The Ugi-4CR has been used for the synthesis of numerous natural substances, e.g., bicyclomycin, furanomycin, penicillin, etc

• component, after the formation of the expected Ugi bisamide products, subsequent post-transformations allow the synthesis of products of intramolecular cyclization [19][20][21][22] and/or products of a tandem combination of several reactions (Scheme 1) [22][23][24][25][26]. At the same time, the use of so

Synthesis and characterization of 1,2,3,4-naphthalene and anthracene diimides

• Adam D. Bass,
• Daniela Castellanos,
• Xavier A. Calicdan and
• Dennis D. Cao

Beilstein J. Org. Chem. 2024, 20, 1767–1772, doi:10.3762/bjoc.20.155

• Adam D. Bass Daniela Castellanos Xavier A. Calicdan Dennis D. Cao Chemistry Department, Macalester College, 1600 Grand Avenue, Saint Paul, Minnesota 55105, United States 10.3762/bjoc.20.155 Abstract We report the synthesis and characterization of naphthalene and anthracene scaffolds end-capped by

• organic thin-film transistors from heteroacenes. Inspired by these results, we sought to demonstrate the preparation of all-carbon scaffolds, i.e., acenes, that are cata-annulated with cyclic imides. Here, we communicate the successful synthesis of 1,2,3,4-NDIs and -ADIs and the characterization of their

• physical properties. Results and Discussion Synthesis The synthesis of the title compounds is shown in Scheme 1. To obtain a naphthalene core with the requisite 1,2,3,4-tetracarbonyl derivatization pattern, we leveraged the cycloaddition of 1 equiv of aryne percursor 1 with 2 equiv of dimethyl

Harnessing unprotected deactivated amines and arylglyoxals in the Ugi reaction for the synthesis of fused complex nitrogen heterocycles

• Javier Gómez-Ayuso,
• Pablo Pertejo,
• Tomás Hermosilla,
• Israel Carreira-Barral,
• Roberto Quesada and
• María García-Valverde

Beilstein J. Org. Chem. 2024, 20, 1758–1766, doi:10.3762/bjoc.20.154

• drugs highlighting their importance in the discovery of novel bioactive compounds. However, their synthesis often faces challenges, including complex functionalization and lengthy reaction sequences. Multicomponent reactions, notably the Ugi reaction, have emerged as powerful tools to address these

• hurdles. Here, we have demonstrated the possibility of using the combination of arylglyoxals and carboxylic acids tethered to nonprotected deactivated amines as a powerful strategy for the synthesis of complex fused heterocycles. The limited nucleophilic character of the amino group of the anthranilic

• reactions have become a useful tool for the synthesis of complex structures which overcome many of these problems, with the Ugi reaction leading these strategies. The scope of the Ugi reaction further increases when coupled with post-condensation reactions, which usually require the use of starting reagents

Synthesis of polycyclic aromatic quinones by continuous flow electrochemical oxidation: anodic methoxylation of polycyclic aromatic phenols (PAPs)

• Hiwot M. Tiruye,
• Solon Economopoulos and
• Kåre B. Jørgensen

Beilstein J. Org. Chem. 2024, 20, 1746–1757, doi:10.3762/bjoc.20.153

• making them less desirable for industrial scale [19]. Electrochemical synthesis methods have a huge potential and this field is currently undergoing a renaissance [20][21][22][23][24]. Replacing chemical oxidants with electric current reduces waste production and gives a sustainable and inherently safe

• alternative to classical synthesis [25][26][27][28]. Electrochemical oxidation reactions are further used to emulate enzymatic oxidations of drugs and explore potential metabolites [29][30][31]. Electrochemical flow systems provide fast electrosynthesis with low cell resistance, large electrode area, and good

• (1a) into o-quinone 5 revealed that the oxidation comprises two separate 1-electron oxidations [38]. Electrooxidative dearomatization has proven to be an effective synthetic tool [39]. However, we have not found examples of electrochemical oxidation of PAPs applied in synthesis. Here, we report the

Syntheses and medicinal chemistry of spiro heterocyclic steroids

• Laura L. Romero-Hernández,
• Ana Isabel Ahuja-Casarín,
• Penélope Merino-Montiel,
• Sara Montiel-Smith,
• José Luis Vega-Báez and
• Jesús Sandoval-Ramírez

Beilstein J. Org. Chem. 2024, 20, 1713–1745, doi:10.3762/bjoc.20.152

• is compelling evidence that incorporating a heterocyclic moiety into a steroid can alter its pharmacological and pharmacokinetic properties, driving intense interest in the synthesis of such hybrids among research groups. In this review, we present an overview of recent synthetic methodologies

• predominant. The outlined synthetic procedures emphasize the pivotal steps for constructing the heterocycles, often accompanied by a detailed account of the overall synthesis pathway. The review encompasses innovative compounds, including bis-steroids linked by a spiro heterocycle and steroids conjugated to

• spirosteroids was underscored by the synthesis of spironolactone [3] (Figure 1), which plays a pivotal role in edema treatment. Aldosterone, implicated in water and salt retention in conditions such as congestive heart failure, hypertension, nephrosis, liver cirrhosis, and toxemia of pregnancy, prompted the

Chemo-enzymatic total synthesis: current approaches toward the integration of chemical and enzymatic transformations

• Ryo Tanifuji and
• Hiroki Oguri

Beilstein J. Org. Chem. 2024, 20, 1693–1712, doi:10.3762/bjoc.20.151

• Ryo Tanifuji Hiroki Oguri Department of Chemistry, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan 10.3762/bjoc.20.151 Abstract A steadily increasing number of reports have been published on chemo-enzymatic synthesis methods that integrate

• biosynthetic enzymatic transformations with chemical conversions. This review focuses on the total synthesis of natural products and classifies the enzymatic reactions into three categories. The total synthesis of five natural products: cotylenol, trichodimerol, chalcomoracin, tylactone, and saframycin A, as

• well as their analogs, is outlined with an emphasis on comparing these chemo-enzymatic syntheses with the corresponding natural biosynthetic pathways. Keywords: chemo-enzymatic synthesis; late-stage modification; reactive biosynthetic intermediate; regio- and stereoselective (macro)cyclization; total

A fiber-optic spectroscopic setup for isomerization quantum yield determination

• Anouk Volker,
• Jorn D. Steen and
• Stefano Crespi

Beilstein J. Org. Chem. 2024, 20, 1684–1692, doi:10.3762/bjoc.20.150

• Table S2 (Supporting Information File 1). Calculated quantum yields and related quantum yields from the literature. Supporting Information Supporting Information File 4: Scripts description, configuration and supplementary data. Acknowledgements A.V. thanks J. J. van der Wal for the synthesis of

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

• established in several oxidative transformations including the synthesis of complex molecules and drugs [12][13]. The most prominent examples are the pentavalent derivatives 2-iodoxybenzoic acid (IBX) and Dess–Martin periodinane (DMP) [14][15]. Although mild and selective oxidants, these highly oxidized λ5

• 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

• iodanes (NHIs) as effective λ3-iodane oxidants for the selective synthesis of ketones and aldehydes, avoiding overoxidation to carboxylic acids. The developed protocols proved particularly effective for benzylic alcohols, yielding good to excellent results. The beneficial role of chloride salt additives