Chemical structure metagenomics of microbial natural products: surveying nonribosomal peptides and beyond

• Thomas Ma and
• John Chu

Beilstein J. Org. Chem. 2024, 20, 3050–3060, doi:10.3762/bjoc.20.253

• recent years and new methods capable of exploring the natural product chemical space more broadly and more efficiently is in urgent need. Chemical structure metagenomics as one such method is the theme of this Perspective. It emphasizes a chemical-structure-centered viewpoint toward natural product

• of almost any bioactivity of interest that originate from plants, fungi, and even animals (such as sponges and corals). Perspective BGF can access only a fraction of the natural product chemical space For nearly a century, BGF has been the method of choice and identified the vast majority of natural

• morphology of the host, etc. [25]. Sequence and function metagenomic approaches have been reviewed elsewhere and will not be covered herein [26][27][28]. This Perspective focuses on chemical structure metagenomics (Figure 2c), an emerging field that integrates bioinformatics, chemical synthesis, molecular

Photoluminescence color-tuning with polymer-dispersed fluorescent films containing two fluorinated diphenylacetylene-type fluorophores

• Kazuki Kobayashi,
• Shigeyuki Yamada,
• Motohiro Yasui and
• Tsutomu Konno

Beilstein J. Org. Chem. 2024, 20, 2682–2690, doi:10.3762/bjoc.20.225

• could be developed by precisely controlling the two-component mixture system of blue- and yellow-fluorescent molecules. From the perspective of both the PL color and ΦPL, we selected the methoxy-substituted compound 1a as an effective blue-fluorescent molecule for use in a two-component mixing system

A review of recent advances in electrochemical and photoelectrochemical late-stage functionalization classified by anodic oxidation, cathodic reduction, and paired electrolysis

• Nian Li,
• Ruzal Sitdikov,
• Ajit Prabhakar Kale,
• Joost Steverlynck,
• Bo Li and
• Magnus Rueping

Beilstein J. Org. Chem. 2024, 20, 2500–2566, doi:10.3762/bjoc.20.214

• . Subsequently, the generated intermediate 29 is oxidized at the anode, then attacked by the acid to obtain the final product (Scheme 10). C–H bond sulfur functionalization: The direct formation of the CS bond is an attractive way to prepare aryl sulfides. From this perspective, Wu and coworkers developed a

HFIP as a versatile solvent in resorcin[n]arene synthesis

• Hormoz Khosravi,
• Valeria Stevens and
• Raúl Hernández Sánchez

Beilstein J. Org. Chem. 2024, 20, 2469–2475, doi:10.3762/bjoc.20.211

• reported herein may impact the synthesis of other macrocyclic arene species, e.g., calix[n]arenes, calix[4]pyrroles, pillar[n]arenes, and cucurbit[n]urils [90][91][92]. Perspective Supramolecular chemistry is a mature field that has crossed boundaries into many other scientific areas. However, the work

Improved deconvolution of natural products’ protein targets using diagnostic ions from chemical proteomics linkers

• Andreas Wiest and
• Pavel Kielkowski

Beilstein J. Org. Chem. 2024, 20, 2323–2341, doi:10.3762/bjoc.20.199

• compounds. Furthermore, from this perspective, the formed probe–protein covalent conjugate shares many features with naturally occurring protein post-translational modifications (PTMs) offering productive exchange of the techniques and experimental setups used in both fields (Figure 2B) [33][34]. The second

Catalysing (organo-)catalysis: Trends in the application of machine learning to enantioselective organocatalysis

• Stefan P. Schmid,
• Leon Schlosser,
• Frank Glorius and
• Kjell Jorner

Beilstein J. Org. Chem. 2024, 20, 2280–2304, doi:10.3762/bjoc.20.196

• ’ perspective, the exploitation of the concept of mechanistic transferability is a promising avenue for the application of ML in enantioselective organocatalysis, as combining data from multiple reactions enlarges datasets. As such, it is an important stepping stone towards the development of more generally

Factors influencing the performance of organocatalysts immobilised on solid supports: A review

• Zsuzsanna Fehér,
• Dóra Richter,
• Gyula Dargó and
• József Kupai

Beilstein J. Org. Chem. 2024, 20, 2129–2142, doi:10.3762/bjoc.20.183

• and an environmental perspective. An efficient catalytic process is characterised by the fact that the catalyst can be easily and, if possible, completely separated from the reaction mixture. Catalysts can be classified into homogeneous and heterogeneous catalysts. In homogeneous catalysis, the

Efficacy of radical reactions of isocyanides with heteroatom radicals in organic synthesis

• Akiya Ogawa and
• Yuki Yamamoto

Beilstein J. Org. Chem. 2024, 20, 2114–2128, doi:10.3762/bjoc.20.182

• with a variety of heteroatoms. In this Perspective, we review the addition and cyclization reactions of heteroatom radicals with isocyanides and discuss the synthetic prospects of the reaction of isocyanides with heteroatom radicals. Keywords: aza-Bergman cyclization; heteroatom-mixed system; imidoyl

• , systematic studies of addition reactions of heteroatom radicals to isocyanides are still limited. In this perspective paper, we systematically review the addition reactions of heteroatom radicals to isocyanides and discuss prospects. Discussion 1,1-Addition of heteroatom radicals to isocyanides Generation of

• understand the conditions for the generation of heteroatom radicals. In addition, from the perspective of recent green chemistry, the development of environmentally friendly synthetic methods is strongly demanded. In other words, a new synthetic method should have excellent atom economy, produce no waste, be

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

• double Michael addition of γ,δ-unsaturated-β-keto esters or Nazarov reagents with suitable acceptors such as nitroalkenes or alkylideneazalactones [7][8][9][10]. From the perspective of an active methylene containing organic moiety, curcumin and its analogs serve as inexpensive and readily available

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

• oxidation of both N-centers was demonstrated in [19]. The wide variety of the subsequent reaction channels for the radical cations formed under chemical or electrochemical oxidation of diarylamines, as well as availability of variously substituted diarylamines make them perspective starting compounds for

• −1.2V to −1.3 V region (Table 1). In case of S2, the second reduction peak corresponds to the reduction of the carbonyl group. Thus, the electrochemical window for the new salts exceeds 3.5 V; that makes their molten forms perspective for application as ionic liquids. As follows from Table 1, oxidation

Hetero-polycyclic aromatic systems: A data-driven investigation of structure–property relationships

• Sabyasachi Chakraborty,
• Eduardo Mayo Yanes and
• Renana Gershoni-Poranne

Beilstein J. Org. Chem. 2024, 20, 1817–1830, doi:10.3762/bjoc.20.160

• subsequent sections. Influence of heterocycle type In this section, we focus on the character and type of the rings comprising the cc-hPASs, going from the broader perspective (size) to a more detailed view (aromatic/antiaromatic) and finally to the specific type of ring. Size of ring In the broadest sense

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

• perspective, the incorporation of a spiro fragment significantly impacts the properties of the drug candidate. Introducing a spirocyclic moiety often leads to increased potency and selectivity, as observed in comparisons between spirocycles and their non-spiro counterparts. Furthermore, several examples

Regio- and stereochemical stability induced by anomeric and gauche effects in difluorinated pyrrolidines

• Ana Flávia Candida Silva,
• Francisco A. Martins and
• Matheus P. Freitas

Beilstein J. Org. Chem. 2024, 20, 1572–1579, doi:10.3762/bjoc.20.140

• Lewis interactions from a natural bond orbital perspective. Keywords: anomeric effect; fluoropyrrolidine; gauche effect; stereochemistry; Introduction The pyrrolidine ring structure is prevalent in numerous natural alkaloids and is an important feature of the proline and hydroxyproline residues that

Bioinformatic prediction of the stereoselectivity of modular polyketide synthase: an update of the sequence motifs in ketoreductase domain

• Changjun Xiang,
• Shunyu Yao,
• Ruoyu Wang and
• Lihan Zhang

Beilstein J. Org. Chem. 2024, 20, 1476–1485, doi:10.3762/bjoc.20.131

• bioinformatics perspective, and will facilitate accurate stereochemical prediction and genome mining of complex polyketides. Experimental Sequence collection and screening All cis-AT PKS and PKS-NRPS amino acid sequences recorded in MIBiG, as well as the PKS sequences reported in literatures we have curated were

Predicting bond dissociation energies of cyclic hypervalent halogen reagents using DFT calculations and graph attention network model

• Yingbo Shao,
• Zhiyuan Ren,
• Zhihui Han,
• Li Chen,
• Yao Li and
• Xiao-Song Xue

Beilstein J. Org. Chem. 2024, 20, 1444–1452, doi:10.3762/bjoc.20.127

• Supporting Information File 1). The computational homolytic BDEs are presented in Table 1. From the perspective of halogen centers, hypervalent iodine(III) reagents exhibit the highest homolytic BDEs, followed by hypervalent bromine(III) reagents, while hypervalent chlorine(III) reagents have the lowest

• be too reactive to be isolated. From the perspective of transfer groups, the homolytic BDEs of groups with strong trans effects [82][83][84] such as -F, -CCH, -CN, -OCF3, -OTf, -OTs are elevated, while those of -N3, -NH2, -SCF3, etc. are smaller. These results are consistent with our previous studies

Light on the sustainable preparation of aryl-cored dibromides

• Fabrizio Roncaglia,
• Alberto Ughetti,
• Nicola Porcelli,
• Biagio Anderlini,
• Andrea Severini and
• Luca Rigamonti

Beilstein J. Org. Chem. 2024, 20, 1076–1087, doi:10.3762/bjoc.20.95

• significant importance as reactive building blocks in polymer and materials chemistry. Their preparation primarily relies on established synthetic methods using molecular bromine or N-bromosuccinimide, known for their reliability and effectiveness. However, from a sustainability perspective, these methods

Synthesis of new representatives of A₃B-type carboranylporphyrins based on meso-tetra(pentafluorophenyl)porphyrin transformations

• Victoria M. Alpatova,
• Evgeny G. Rys,
• Elena G. Kononova and
• Valentina A. Ol'shevskaya

Beilstein J. Org. Chem. 2024, 20, 767–776, doi:10.3762/bjoc.20.70

• meso-pentafluorophenyl-substituted porphyrins. Carboranes, due to their unique physical and chemical properties such as high chemical and biological stability [28][29], three-dimensional aromaticity [30][31], low toxicity [28], high hydrophobicity, and enriched boron content [32][33] are perspective

Introduction of a human- and keyboard-friendly N-glycan nomenclature

• Friedrich Altmann,
• Johannes Helm,
• Martin Pabst and
• Johannes Stadlmann

Beilstein J. Org. Chem. 2024, 20, 607–620, doi:10.3762/bjoc.20.53

• . Perspective This exposition is not intended to grimly wipe away any other type of annotation. We imagine that it can be of value wherever defined structures shall be named and written down. With increasing uncertainty, any of the systems mentioned in Table 1 may be preferred up to the point where a mere

Switchable molecular tweezers: design and applications

• Pablo Msellem,
• Maksym Dekthiarenko,
• Nihal Hadj Seyd and
• Guillaume Vives

Beilstein J. Org. Chem. 2024, 20, 504–539, doi:10.3762/bjoc.20.45

Ligand effects, solvent cooperation, and large kinetic solvent deuterium isotope effects in gold(I)-catalyzed intramolecular alkene hydroamination

• Ruichen Lan,
• Brock Yager,
• Yoonsun Jee,
• Cynthia S. Day and
• Amanda C. Jones

Beilstein J. Org. Chem. 2024, 20, 479–496, doi:10.3762/bjoc.20.43

• data plots; where not visible they are smaller than the icon for the data point. (a) Schematic for synthesis of [L–Au–L]SbF6 where L = JPhos. (b) Perspective drawing of the cation in crystalline [Au(P(C4H9)2(C12H9))2](SbF6)CH2Cl2 where P are represented by dotted spheres, Au atoms are represented by

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

• of parameters with which to control reactivity. In this perspective, we provide an overview of the different mechanisms for radical reactions involving NHPI esters, with an emphasis on recent applications in radical additions, cyclizations and decarboxylative cross-coupling reactions. Within these

• hydrogen atom transfer (HAT) or sequential electron transfer and proton transfer (ET/PT) steps. Alternatively, redox-neutral transformations can be envisioned using catalytic reductants, which can enable a complementary scope of downstream functionalizations (Scheme 2B). In this perspective, we present an

• significant advantages compared to other methods. It allows for single electron reduction to be facilitated by cost-effective carbon-based cathodes, eliminating the requirement for precious metal photocatalysts or exogeneous reductants such as Zn0. In the final section of this perspective, we explore examples

Catalytic multi-step domino and one-pot reactions

• Svetlana B. Tsogoeva

Beilstein J. Org. Chem. 2024, 20, 254–256, doi:10.3762/bjoc.20.25

• stereocenters [7]. In the Review paper by Kisszékelyi and Šebesta, the diverse variety of chiral metal enolates obtained by asymmetric conjugate additions of organometallic reagents and the possibilities to engage metal enolates in tandem reactions with new electrophiles are presented [8]. A Perspective from X

Photochromic derivatives of indigo: historical overview of development, challenges and applications

• Gökhan Kaplan,
• Zeynel Seferoğlu and
• Daria V. Berdnikova

Beilstein J. Org. Chem. 2024, 20, 228–242, doi:10.3762/bjoc.20.23

• view of historical development perspective of these compounds. Additionally, we highlight the recent advances in the photoswitching of the structural derivatives of indigo (indirubin and isoindigo) as well as outline the reported applications of photochromic indigos. Overall, we hope that this review

Substituent-controlled construction of A₄B₂-hexaphyrins and A₃B-porphyrins: a mechanistic evaluation

• Seda Cinar,
• Dilek Isik Tasgin and
• Canan Unaleroglu

Beilstein J. Org. Chem. 2023, 19, 1832–1840, doi:10.3762/bjoc.19.135

• aryl-bearing N-tosylimines, but a 4-(CF3)C6H4 group led only to the formation of porphyrin compounds. A mechanistic perspective for the formation of porphyrinic products was acquired via a set of high-resolution mass analyses of selected model reactions. The results indicated that azafulvene-ended

A novel recyclable organocatalyst for the gram-scale enantioselective synthesis of (S)-baclofen

• Gyula Dargó,
• Dóra Erdélyi,
• Balázs Molnár,
• Péter Kisszékelyi,
• Zsófia Garádi and
• József Kupai

Beilstein J. Org. Chem. 2023, 19, 1811–1824, doi:10.3762/bjoc.19.133

• and toluene, while using 2-MeTHF drastically decreased the enantioselectivity. From the perspective of green chemistry, anisole would be more favorable, but toluene is also a distinctly better alternative to the other solvents (e.g., DCM) commonly used in Michael additions. Another critical aspect