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

• without sacrificing stability, while future design of chiral ligands may depend on a better understanding of the chiral space generated when gold is coordinated to carbonyl functionality, rather than the alkene. Key observations include the following: • Mixed solvent effects support the involvement of

Development of a chemical scaffold for inhibiting nonribosomal peptide synthetases in live bacterial cells

• Fumihiro Ishikawa,
• Sho Konno,
• Hideaki Kakeya and
• Genzoh Tanabe

Beilstein J. Org. Chem. 2024, 20, 445–451, doi:10.3762/bjoc.20.39

• previously described an activity-based protein profiling (ABPP) strategy for NRPSs using ABPs that target A-domains (Figure 2b) [13][14][15]. The probes comprise an aminoacyl-AMS ligand and a photoaffinity group with clickable alkyne functionality appended to the 2′-OH group of adenosine. A complex structure

• and 9 exhibited lower affinity than inhibitors 1, 2, 4, 5, and 7. This result suggests that the incorporation of the pegylated functionality at the 2′-OH group of the adenosine skeleton particularly perturbs binding via steric hindrance. Next, we investigated whether ʟ-Phe-AMS derivatives could

Synthesis of the 3’-O-sulfated TF antigen with a TEG-N₃ linker for glycodendrimersomes preparation to study lectin binding

• Mark Reihill,
• Hanyue Ma,
• Dennis Bengtsson and
• Stefan Oscarson

Beilstein J. Org. Chem. 2024, 20, 173–180, doi:10.3762/bjoc.20.17

• at this stage was predicted to be problematic. Therefore, the azido functionality was installed in the spacer before the glycosylation. Donor 3 underwent an NIS/AgOTf-promoted glycosylation with the TEG-N3 acceptor [18], furnishing α-linked 4 in an 85% yield (Scheme 1). H-1 appeared as a doublet at

NMRium: Teaching nuclear magnetic resonance spectra interpretation in an online platform

• Luc Patiny,
• Hamed Musallam,
• Alejandro Bolaños,
• Michaël Zasso,
• Julien Wist,
• Metin Karayilan,
• Eva Ziegler,
• Johannes C. Liermann and
• Nils E. Schlörer

Beilstein J. Org. Chem. 2024, 20, 25–31, doi:10.3762/bjoc.20.4

• which can be embedded in other websites for more advanced teaching scenarios. Teaching NMR assignment Finally, teachers can also give their more advanced students assignments without the online quiz functionality, by providing spectra or a complete .nmrium dataset for the students to process, analyze

• grasp functionality would make it a preselected tool for the review process of chemistry publications. Future developments of NMRium include the processing of 2D NMR experiments, as well as a CASE- and prediction-supported assignment tool with an integrated validation function for assigned data [44

• ]. Currently, first implementations of NMRium in other environments have already successfully started. NMRium.org user interface showing a 2D NMR quiz for an unknown compound with a given molecular formula. NMRium interface assignment functionality for a drag-and-drop example. Analysis of overlapping signals

Quinoxaline derivatives as attractive electron-transporting materials

• Zeeshan Abid,
• Liaqat Ali,
• Sughra Gulzar,
• Faiza Wahad,
• Raja Shahid Ashraf and
• Christian B. Nielsen

Beilstein J. Org. Chem. 2023, 19, 1694–1712, doi:10.3762/bjoc.19.124

• processability compared to their inorganic counterparts [1][2]. Charge transport in organic semiconductors is a fundamental aspect that governs the performance and functionality of various organic semiconductor devices, such as organic solar cells (OSCs), organic field-effect transistors (OFETs), organic light

Radical chemistry in polymer science: an overview and recent advances

• Zixiao Wang,
• Feichen Cui,
• Yang Sui and
• Jiajun Yan

Beilstein J. Org. Chem. 2023, 19, 1580–1603, doi:10.3762/bjoc.19.116

• employed technique for industrial production of polymeric materials, and other polymer synthesis involving a radical process. Post-polymerization modification, including polymer crosslinking and polymer surface modification, is the key process that introduces functionality and practicality to polymeric

• ]. In a typical thiol–ene system, the polymerization undergoes a free-radical chain mechanism, involving an initiation step from a thiol group via radical transfer or homolysis (Scheme 11, initiation), radical addition of the thiyl radical to the ene functionality (propagation 1), transfer from the

C–H bond functionalization: recent discoveries and future directions

• Indranil Chatterjee

Beilstein J. Org. Chem. 2023, 19, 1568–1569, doi:10.3762/bjoc.19.114

• feedstocks, the introduction of functionality at specific positions of molecules without requiring any prefunctionalized precursors, and the conversion of light alkanes to higher-value analogues [1][2]. The nonnecessity of prefunctionalization provides a step-economic alternative to classical reactions as

Functional characterisation of twelve terpene synthases from actinobacteria

• Anuj K. Chhalodia,
• Houchao Xu,
• Georges B. Tabekoueng,
• Binbin Gu,
• Kizerbo A. Taizoumbe,
• Lukas Lauterbach and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2023, 19, 1386–1398, doi:10.3762/bjoc.19.100

• ), geranylgeranyl pyrophosphate (GGPP) and geranylfarnesyl pyrophosphate (GFPP). Sesquiterpene synthases The enzyme from K. kofuensis (Table 1, entry 1) exhibited all highly conserved motifs required for functionality including the aspartate-rich motif (83DDAYCD) and the NSE triad (223NDIASYYKE, Figure S2

Non-noble metal-catalyzed cross-dehydrogenation coupling (CDC) involving ether α-C(sp³)–H to construct C–C bonds

• Hui Yu and
• Feng Xu

Beilstein J. Org. Chem. 2023, 19, 1259–1288, doi:10.3762/bjoc.19.94

• synthesis of compounds with quaternary centers and natural products with high structural complexity. In 2014, Li et al. reported a CuCl2-catalyzed cross-dehydrogenation coupling reaction of C(sp3)–H bonds adjacent to an ether oxygen and the C(sp3)–H bonds at the α-position of a carbonyl functionality in the

Acetaldehyde in the Enders triple cascade reaction via acetaldehyde dimethyl acetal

• Alessandro Brusa,
• Debora Iapadre,
• Maria Edith Casacchia,
• Alessio Carioscia,
• Giuliana Giorgianni,
• Giandomenico Magagnano,
• Fabio Pesciaioli and
• Armando Carlone

Beilstein J. Org. Chem. 2023, 19, 1243–1250, doi:10.3762/bjoc.19.92

• which two or more bond-forming steps happen under identical reaction conditions, and where a subsequent transformation takes place at the functionality obtained in the former bond-forming event. Cascade reactions are valuable tools for streamlining the synthesis of structurally complex molecules in a

Radical ligand transfer: a general strategy for radical functionalization

• David T. Nemoto Jr,
• Kang-Jie Bian,
• Shih-Chieh Kao and
• Julian G. West

Beilstein J. Org. Chem. 2023, 19, 1225–1233, doi:10.3762/bjoc.19.90

• (XAT) from the alkyl halide reagent and further oxidation of the transient radical to a carbocation by radical polar crossover (RPC), providing two mechanistic pathways to form the ATRA products [32]. While powerful, this approach is inherently incompatible with introducing alternative functionality

Two new lanostanoid glycosides isolated from a Kenyan polypore Fomitopsis carnea

• Winnie Chemutai Sum,
• Sherif S. Ebada,
• Didsanutda Gonkhom,
• Cony Decock,
• Rémy Bertrand Teponno,
• Josphat Clement Matasyoh and
• Marc Stadler

Beilstein J. Org. Chem. 2023, 19, 1161–1169, doi:10.3762/bjoc.19.84

• into a ketone moiety diminished the activity [31]. Similar findings on the related polyporenic acid B, with significant IC50 values between 8.4–12.2 µM [22], confirms the probable crucial role played by the 3-OH group in improving the potency. The presence of the 3-O-methylglutaroyl functionality in

Photoredox catalysis harvesting multiple photon or electrochemical energies

• Mattia Lepori,
• Simon Schmid and
• Joshua P. Barham

Beilstein J. Org. Chem. 2023, 19, 1055–1145, doi:10.3762/bjoc.19.81

• products, demonstrating a clear preference for addition to alkenes even in the presence of alkyne functionalities. Due to basic conditions of the reductive quenching (RQ) route, the formation of lactone side product 30h could be observed with a carboxylic acid functionality. In the absence of Et3N, the

Aromatic C–H bond functionalization through organocatalyzed asymmetric intermolecular aza-Friedel–Crafts reaction: a recent update

• Anup Biswas

Beilstein J. Org. Chem. 2023, 19, 956–981, doi:10.3762/bjoc.19.72

• with the elimination of a H+ ion to form the functionalized aromatic moieties. The aza-Friedel–Crafts reaction is a subclass of the originally reported transformation that couples an imine with an aromatic system allowing for a facile incorporation of an alkylamine functionality into the aromatic

• aryl moieties. For this purpose, sterically bulky substituents need to be present in the aryl ring attached to the C3 position of the starting indoles. The axial chirality was attributed to ester and phenolic OH groups at the ortho-positions of the aryl ring and an additional phenolic OH functionality

• in 83 and the enantioregulation was achieved by BINOL-derived chiral phosphoric acid P22. An amine functionality was crucial in the isoxazole ring to enhance the nucleophilicity of the adjacent carbon atom. In addition, the amine hydrogen forms an H-bond with the catalyst along with another hydrogen

Photoredox catalysis enabling decarboxylative radical cyclization of γ,γ-dimethylallyltryptophan (DMAT) derivatives: formal synthesis of 6,7-secoagroclavine

• Alessio Regni,
• Francesca Bartoccini and
• Giovanni Piersanti

Beilstein J. Org. Chem. 2023, 19, 918–927, doi:10.3762/bjoc.19.70

• cyclization event would be triggered using their innate functionality, namely the α-amino carboxylate, through photoredox-mediated oxidative activation and CO2 extrusion, without the need for acid prefunctionalization to the redox-activated ester. Consequently, a technique involving direct generation of α

First synthesis of acylated nitrocyclopropanes

• Kento Iwai,
• Rikiya Kamidate,
• Khimiya Wada,
• Haruyasu Asahara and
• Nagatoshi Nishiwaki

Beilstein J. Org. Chem. 2023, 19, 892–900, doi:10.3762/bjoc.19.67

• reaction with dinucleophiles such as 2-aminopyridines, which affords pyrido[1,2-a]pyrimidinones through ring opening (Scheme 1, reaction a) [1]. Chemical transformations that take advantage of polyfunctionality are also possible. A six-membered ring forms between the aryl group and ester functionality

Palladium-catalyzed enantioselective three-component synthesis of α-arylglycine derivatives from glyoxylic acid, sulfonamides and aryltrifluoroborates

• Bastian Jakob,
• Nico Schneider,
• Luca Gengenbach and
• Georg Manolikakes

Beilstein J. Org. Chem. 2023, 19, 719–726, doi:10.3762/bjoc.19.52

• these transformations to a palladium-catalyzed enantioselective synthesis of α-arylglycine bearing a free carboxylic acid functionality directly from the parent glyoxylic acids (Scheme 1c) [22]. We could show that the desired arylglycine can be synthesized in good to excellent enantioselectivities

Photocatalytic sequential C–H functionalization expediting acetoxymalonylation of imidazo heterocycles

• Deepak Singh,
• Shyamal Pramanik and
• Soumitra Maity

Beilstein J. Org. Chem. 2023, 19, 666–673, doi:10.3762/bjoc.19.48

• boron complex (B2pin2), and using an expensive metal-based photocatalyst [fac-Ir(ppy)3] under inert atmosphere. We have recently demonstrated that aerial oxygen could be captured by alkyl radicals to install a keto-functionality onto alkenes in an organophotocatalytic way [23]. We aimed to extend this

Cassane diterpenoids with α-glucosidase inhibitory activity from the fruits of Pterolobium macropterum

• Sarot Cheenpracha,
• Ratchanaporn Chokchaisiri,
• Lucksagoon Ganranoo,
• Sareeya Bureekaew,
• Thunwadee Limtharakul and
• Surat Laphookhieo

Beilstein J. Org. Chem. 2023, 19, 658–665, doi:10.3762/bjoc.19.47

• -lactone functionality. The 13C NMR and DEPT spectra in combination with HMQC data (Table 1) showed resonances of 44 carbons which were classified as nine methyls, 11 methylenes, 11 methines (three oxygenated sp3 at δC 73.7, 69.4, 68.8), and 13 quaternary carbons (four carbonyls at δC 197.9, 170.7, 170.4

Enolates ambushed – asymmetric tandem conjugate addition and subsequent enolate trapping with conventional and less traditional electrophiles

• Péter Kisszékelyi and
• Radovan Šebesta

Beilstein J. Org. Chem. 2023, 19, 593–634, doi:10.3762/bjoc.19.44

• building blocks providing an aminomethyl moiety upon adding nucleophiles. Protected formaldehyde aminals are useful synthetic equivalents to formaldehyde imines. The imine functionality can be unmasked (68) in the reaction medium by Lewis acids such as TiCl4. The formed Mg enolates 66 readily react with

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

• reaction conditions, without adding additional reagents and catalysts, and in which the subsequent reactions result as a consequence of the functionality formed in previous steps [1]. Bicyclic alkenes, a family of strained ring systems, have seen widespread applications in organic synthesis in the last 20

• reaction (vide infra). The reaction seems to be sensitive to the steric bulk of the amide functionality with n-propyl and isopropylamides having diminished yields. While the scope of anilides was quite extensive, electron-deficient substrates resulted in lowered yields. In 2022, the Jeganmohan group

Synthesis, α-mannosidase inhibition studies and molecular modeling of 1,4-imino-ᴅ-lyxitols and their C-5-altered N-arylalkyl derivatives

• Martin Kalník,
• Sergej Šesták,
• Juraj Kóňa,
• Maroš Bella and
• Monika Poláková

Beilstein J. Org. Chem. 2023, 19, 282–293, doi:10.3762/bjoc.19.24

• -benzyl group with the Cbz group, trityl ether hydrolysis, oxidation of the liberated OH group, and stereoselective addition of MeMgBr to the resulting aldehyde functionality. Hydrogenolysis of the Cbz protecting group in 13 followed by N-alkylation afforded pyrrolidines 14–16 which after acidic

An efficient metal-free and catalyst-free C–S/C–O bond-formation strategy: synthesis of pyrazole-conjugated thioamides and amides

• Shubham Sharma,
• Dharmender Singh,
• Sunit Kumar,
• Vaishali,
• Rahul Jamra,
• Naveen Banyal,
• Deepika,
• Chandi C. Malakar and
• Virender Singh

Beilstein J. Org. Chem. 2023, 19, 231–244, doi:10.3762/bjoc.19.22

• ]. Substituted pyrazoles are also of considerable interest because of their synthetic utility as chiral auxiliaries [32], synthetic reagents in multicomponent reactions [33][34], and guanylating agents [35]. The installation of a thioamide functionality has attracted an immense attention in medicinal chemistry

• pharmaceutical ingredients [48] such as fenclosic acid, fentiazac, and febuxostate. Similarly, in contemporary chemistry, the amide functionality is one of the most studied functional groups. Specifically, this moiety is vital for the formation of the backbone of structural proteins and enzymes [49]. The amide

• the thioamide functionality including base-catalyzed Willgerodt–Kindler reaction [54], Kindler reaction in the presence of sulfated tungstate [55], thionation of amides using thionating reagents [56] and thionation of amides using TsCl (4-toluenesulfonyl chloride) or PSCl3-mediated Beckmann

An accelerated Rauhut–Currier dimerization enabled the synthesis of (±)-incarvilleatone and anticancer studies

• Tharun K. Kotammagari,
• Sweta Misra,
• Sayantan Paul,
• Sunita Kunte,
• Rajesh G. Gonnade,
• Manas K. Santra and
• Asish K. Bhattacharya

Beilstein J. Org. Chem. 2023, 19, 204–211, doi:10.3762/bjoc.19.19

• ) dimerization has some limitations, such as its controlling selectivity for intermolecular reactions in differently activated alkenes, and low reactivity. Han and co-workers [6] addressed the latter one by designing a substrate in which nucleophile functionality is also present in the Michael acceptor to

• addition reaction involved. The low reactivity of intermolecular RC reactions can be improved by incorporating the nucleophilic functionality within a molecule like I (Scheme 1). This nucleophilic functionality present within the enone system first undergoes an intramolecular conjugate addition and is

• functionality (hydroxy group) and an enone system within the same molecule are needed to accelerate the intermolecular RC reaction. Results and Discussion A retrosynthetic plan for the synthesis of (±)-incarvilleatone (1) and (±)-incarviditone (2) is delineated in Scheme 2. We envisaged that both the natural

Sequential hydrozirconation/Pd-catalyzed cross coupling of acyl chlorides towards conjugated (2E,4E)-dienones

• Benedikt Kolb,
• Daniela Silva dos Santos,
• Sanja Krause,
• Anna Zens and
• Sabine Laschat

Beilstein J. Org. Chem. 2023, 19, 176–185, doi:10.3762/bjoc.19.17

• benzoyl chloride (26a). The best results were obtained in the reaction of aliphatic enyne 25e with benzoyl chloride (26a) and acetyl chloride (22) in yields of 34% and 65%, respectively. Methyl substitution on the alkene functionality of enyne 25 did not affect the yield, however, methyl substitution at