Recent advancements in iodide/phosphine-mediated photoredox radical reactions

• Tinglan Liu,
• Yu Zhou,
• Junhong Tang and
• Chengming Wang

Beilstein J. Org. Chem. 2023, 19, 1785–1803, doi:10.3762/bjoc.19.131

• Tinglan Liu Yu Zhou Junhong Tang Chengming Wang Department of Chemistry, Jinan University, Guangzhou 511443, P. R. China UNITEST, Weifang 261000, P. R. China 10.3762/bjoc.19.131 Abstract Photoredox catalysis plays a crucial role in contemporary synthetic organic chemistry. Since the

• , numerous remarkable breakthroughs and notable progresses have been achieved in the realm of photoredox catalysis [1][2][3]. This domain has profoundly transformed modern organic synthesis, resulting in a considerable surge in research efforts centered on free radical reactions [4]. Presently, photoredox

• catalysis has risen to prominence as an incredibly effective methodology, establishing itself as a powerful tool for crafting various C–X (X = C, N, O, F, Cl…) bonds owing to its advantageous traits, such as sustainability, practicality, and environmental compatibility [5]. Despite its broad synthetic

Active-metal template clipping synthesis of novel [2]rotaxanes

• Cătălin C. Anghel,
• Teodor A. Cucuiet,
• Niculina D. Hădade and
• Ion Grosu

Beilstein J. Org. Chem. 2023, 19, 1776–1784, doi:10.3762/bjoc.19.130

• ; Department of Organic Chemistry, Biochemistry and Catalysis, Research Centre of Applied Organic Chemistry, 90-92 Panduri Street, RO-050663 Bucharest, Romania 10.3762/bjoc.19.130 Abstract Mechanically interlocked molecules (MIMs) have been important synthetic targets in supramolecular chemistry due to their

• in 2016. While initially obtained as chemical curiosities, rotaxanes offer now exciting opportunities for scientific advancements in supramolecular chemistry and applications in various fields ranging from molecular machines and switches [4][5][6][7][8][9] to catalysis [10][11], molecular electronics

• -functonalized stopper 3 after substitution of bromine with azide. The dialkyne-decorated pyridine 5 was prepared starting from 2,6-bis(bromomethyl)pyridine that was reacted with compound 4, under phase transfer catalysis (Scheme 1). Finally, the axle 6, as well as the reference macrocycles M1 and M2 [44], were

Selectivity control towards CO versus H₂ for photo-driven CO₂ reduction with a novel Co(II) catalyst

• Lisa-Lou Gracia,
• Philip Henkel,
• Olaf Fuhr and
• Claudia Bizzarri

Beilstein J. Org. Chem. 2023, 19, 1766–1775, doi:10.3762/bjoc.19.129

• (helping in the deprotonation of the radical cation BIH•+ formed after the reductive quenching of the PS), but also can actively assist the catalysis, by capturing CO2 [50][51][52]. On the other hand, having three hydroxy groups, TEOA is also considered a proton donor and the formation of metal hydrides is

• possible. In some cases, this metal hydride favors the production of formate [51]. However, it may induce the concomitant formation of H2. This might have been the case of the photo-driven catalysis by complex 1 in DMA/TEOA (Table 2, entries 2–4), where upon decreasing the concentration of TEOA down to

• with a TON ≈ 61 after 4 h (Table 3, entry 5). Longer irradiation times (15 h) were evaluated for the concentration of 10 μM and 5 μM of complex 1, showing that the catalysis continued beyond 4 hours and reached a TON higher than 80 and 50, for [1] of 5 and 10 μM, respectively (Table 3, entries 6 and 7

Trifluoromethylated hydrazones and acylhydrazones as potent nitrogen-containing fluorinated building blocks

• Zhang Dongxu

Beilstein J. Org. Chem. 2023, 19, 1741–1754, doi:10.3762/bjoc.19.127

• catalysis, for the synthesis of trifluoromethylated dihydropyridazines under simple reaction conditions and the chemistry displayed very good enantioselectivities and high functional group tolerance (Scheme 4) [40]. Zhan et al. reported an efficient and highly selective method for the synthesis of CF3

• Brønsted acid-assisted Lewis base catalysis. Synthesis of CF3-pyrazoles and CF3-1,6-dihydropyridazines. Asymmetric reactions of trifluoromethylimines with organometallic reagents. Mannich-type reaction of trifluoroacetaldehyde hydrazones. Synthesis of trifluoromethylated hydrazonoyl halides. Early work of

Unprecedented synthesis of a 14-membered hexaazamacrocycle

• Anastasia A. Fesenko and
• Anatoly D. Shutalev

Beilstein J. Org. Chem. 2023, 19, 1728–1740, doi:10.3762/bjoc.19.126

• agents for magnetic resonance imaging, radiopharmaceuticals, sensors, NMR shift reagents, luminescent materials, catalysis, etc. To date, a large variety of PAMs with various ring sizes, number and location of nitrogen atoms, levels of unsaturation, etc. have been prepared and studied. Nevertheless, the

Decarboxylative 1,3-dipolar cycloaddition of amino acids for the synthesis of heterocyclic compounds

• Xiaofeng Zhang,
• Xiaoming Ma and
• Wei Zhang

Beilstein J. Org. Chem. 2023, 19, 1677–1693, doi:10.3762/bjoc.19.123

• under the catalysis of AcOH at 110 °C for 6 h afforded the monocycloaddition product 19a in 93% LC yield [71]. The isolated compound 19a was used for an N-propargylation to produce compound 20a in 94% LC yield. The following Cu-catalyzed click reaction afforded triazolobenzodiazepine 21a in 88% LC yield

• ]isoquinolines. The reaction of 2-bromobenzaldehydes, 2-aminoisobutyric acid, and maleimides in MeCN under the catalysis of AcOH at 110 °C for 6 h afforded the cycloaddition products 26. The purified intermediates were used for the one-pot N-allylation with allyl bromide to afford intermediate 25 followed by a

Tying a knot between crown ethers and porphyrins

• Maksym Matviyishyn and
• Bartosz Szyszko

Beilstein J. Org. Chem. 2023, 19, 1630–1650, doi:10.3762/bjoc.19.120

• porphyrins as multitopic receptors, sensors, and supramolecular hosts, with applications in ion transport, catalysis, and polymeric materials [22][40][41][42][43][44][45]. In 1984 Lehn, Sessler and co-workers developed double-side-strapped crowned porphyrins, which served as tritopic and tetratopic receptors

• multitopic receptors capable of binding ions and ion-pairs, which have been used in ion binding and catalysis, to name a few applications [47][48][49]. A primary example of a crown ether-annulated porphyrin, i.e., β-crowned porphyrin, was established in 1996 by Murashima and co-workers [50]. The macrocycle

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

• its combination with organometallic chemistry for site-selective C−H bond functionalization [3][4]. Recent years have witnessed many viable strategies for the synthesis of complex targets utilizing photoredox catalysis, electroorganic catalysis, Lewis acid catalysis, and transition-metal-free

Morpholine-mediated defluorinative cycloaddition of gem-difluoroalkenes and organic azides

• Tzu-Yu Huang,
• Mario Djugovski,
• Sweta Adhikari,
• Destinee L. Manning and
• Sudeshna Roy

Beilstein J. Org. Chem. 2023, 19, 1545–1554, doi:10.3762/bjoc.19.111

• are typically accessed in two ways: (1) direct synthesis using metal or metal-free catalysis and (2) post-functionalization of disubstituted-1,2,3-triazoles [17][18]. The direct synthesis of fully substituted triazoles entails either metal-free carbonyl-based [19][20][21] or metal-mediated and strain

N-Sulfenylsuccinimide/phthalimide: an alternative sulfenylating reagent in organic transformations

• Fatemeh Doraghi,
• Seyedeh Pegah Aledavoud,
• Mehdi Ghanbarlou,
• Bagher Larijani and
• Mohammad Mahdavi

Beilstein J. Org. Chem. 2023, 19, 1471–1502, doi:10.3762/bjoc.19.106

• nucleophilic attack of TMSN3 to deliver product 11 (Scheme 7). Tian and Chang et al. could synthesize 3‑sulfenylated coumarin compounds 13 by using N-sulfanylsuccinimides 1 under a Lewis acid catalysis system (Scheme 8) [48]. Additionally, oxidation of 3-sulfenylated coumarins utilizing (diacetoxyiodo)benzene

• -(arylthio)succinimides 1 or N-(arylseleno)succinimides 1’’ was developed under a Lewis acid catalysis system. This reaction involves ring-opening of the substituted cyclopropane 49, amination at the C1-site, and thiolation at the C3-site. In the transformation, sulfonamide acted as a nucleophile

• an effective catalysis system (Scheme 29) [63]. Kinetic studies in this cross coupling-reaction indicated that N-(arylthio)succinimides 1 with electron-deficient arene 4 undergoe thioarylation catalyzed by Fe(NTf2)3. Related molecules bearing an electron-rich arene showed an autocatalytic pathway

Application of N-heterocyclic carbene–Cu(I) complexes as catalysts in organic synthesis: a review

• Nosheen Beig,
• Varsha Goyal and
• Raj K. Bansal

Beilstein J. Org. Chem. 2023, 19, 1408–1442, doi:10.3762/bjoc.19.102

• . A number of excellent reviews on different aspects of NHC chemistry has been published during this period [12][13][14]. NHCs have been widely employed in homogeneous catalysis [12] and as ligands for the preparation of coordination compounds of different metals [13]. The M–NHC bond is relatively

• stable; as a result, the stability of the resulting metal complexes is enhanced [14]. This has led to the development of a variety of NHC-incorporating metal compounds exhibiting increased activity/selectivity in catalysis [15]. Nature of the NHC–metal bond NHCs constitute a well-established class of

• [(IMes)2Cu]+FHF− (91) was also obtained. These complexes exhibit an interesting catalytic activity that will be described later. 2 Application as catalysts In 2001, Woodward, for the first time, reported an NHC–Cu-mediated catalysis in the conjugate addition of diethylzinc to enones (Scheme 33) [46

One-pot nucleophilic substitution–double click reactions of biazides leading to functionalized bis(1,2,3-triazole) derivatives

• Hans-Ulrich Reissig and
• Fei Yu

Beilstein J. Org. Chem. 2023, 19, 1399–1407, doi:10.3762/bjoc.19.101

• carbohydrate mimetics, but the reductive cleavage of the 1,2-oxazine rings to aminopyran moieties did not proceed cleanly with these compounds. Keywords: alkynes; azides; copper catalysis; nucleophilic substitution; 1,2-oxazines; Introduction The concept of click reactions [1][2], in particular, the

• reductive ring openings of bis(1,2,3-triazole) derivative 21 to divalent carbohydrate mimetics with hydrogen under palladium catalysis or with samarium diiodide did not proceed cleanly and need further optimization. Earlier approaches to multivalent carbohydrate mimetics B, D or F based on enantiopure

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

• -α-eudesmol synthase from S. viridochromogenes [29][30]. In order to expand the knowledge about terpene synthase catalysis, fifteen uncharacterised terpene synthase homologs as listed in Table 1 were selected for further studies from different branches of the tree (indicated by red arrows in Figure 2

Consecutive four-component synthesis of trisubstituted 3-iodoindoles by an alkynylation–cyclization–iodination–alkylation sequence

• Nadia Ledermann,
• Alae-Eddine Moubsit and
• Thomas J. J. Müller

Beilstein J. Org. Chem. 2023, 19, 1379–1385, doi:10.3762/bjoc.19.99

• state, in good yield. Keywords: alkynylation; catalysis; cyclization; indoles; iodination; multicomponent reactions; Introduction Indoles and their derived substitution patterns are omnipresent heterocyclic structural motifs in nature [1], many natural products [2][3], drugs [4][5][6][7][8], and dyes

• transition-metal catalysis [31], we disclosed an activating group-free alkynylation–cyclization sequence to (aza)indoles [32][33] that could be readily concatenated with a concluding N-alkylation of the 7-azaindole intermediate in the sense of consecutive three-component coupling–cyclization–alkylation

Visible-light-induced nickel-catalyzed α-hydroxytrifluoroethylation of alkyl carboxylic acids: Access to trifluoromethyl alkyl acyloins

• Feng Chen,
• Xiu-Hua Xu,
• Zeng-Hao Chen,
• Yue Chen and
• Feng-Ling Qing

Beilstein J. Org. Chem. 2023, 19, 1372–1378, doi:10.3762/bjoc.19.98

• trifluoromethyl alkyl acyloins in good yields with broad substrate compatibility. The complex bioactive molecules were also compatible with this catalytic system to afford the corresponding products. Keywords: alkyl carboxylic acids; cross coupling; EDA complex; nickel catalysis; trifluoromethyl acyloins

Synthesis of ether lipids: natural compounds and analogues

• Marco Antônio G. B. Gomes,
• Alicia Bauduin,
• Chloé Le Roux,
• Romain Fouinneteau,
• Wilfried Berthe,
• Mathieu Berchel,
• Hélène Couthon and
• Paul-Alain Jaffrès

Beilstein J. Org. Chem. 2023, 19, 1299–1369, doi:10.3762/bjoc.19.96

• with mCPBA produced the epoxide 13.3. Then, the addition of benzoic acid in the presence of acid catalysis produced an ester that was saponified to yield the diol 13.4. A three-step sequence is applied to produce compound 13.5 that features a secondary alcohol protected with a benzyl group. Then, the

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

• drug and natural compounds containing functionalized ether α-C(sp3)–H bonds CDC reactions can be applied. This review mainly focuses on the CDC reactions of ether oxygen α-C(sp3)–H bonds via non-noble metal-catalysis (Scheme 1d). Review Non-noble metal-catalyzed CDC reactions involving ether α-C(sp3)–H

• directing groups could be used as coupling partners. The ligand acts as an activator of the catalyst to promote the reaction, and the iron-bound anion plays a crucial role in catalysis. This reaction might occur via a radical pathway, with the iron catalyst playing a significant role in electron transfer

• unique catalytic behavior [89]. However, there are only a few examples of cobalt catalysis in CDC reactions. Limited by the activity of Co catalysts, there are few examples of Co-catalyzed reactions involving ether C(sp3)–H bond activation. The Co-catalyzed C(sp3)–C(sp3) CDC of glycine and peptide

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

• reaction for the synthesis of polyfunctionalized cyclohexenes bearing multiple stereocenters. The reaction is promoted by a chiral secondary amine, which is capable of catalyzing each step of the process activating the substrates through enamine and iminium ion catalysis towards a Michael/Michael/aldol

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

• driven by several key features of RLT catalysis, including the ability to form diverse bonds (including C–X, C–N, and C–S), the use of simple earth abundant element catalysts, and the intrinsic compatibility of this approach with varied radical generation methods, including HAT, radical addition, and

• decarboxylation. Here, we provide an overview of the evolution of RLT catalysis from initial studies to recent advances and provide a conceptual framework we hope will inspire and enable future work using this versatile elementary step. Keywords: catalysis; cooperative catalysis; earth abundant elements

• center. Subsequent reoxidation of the metal with coordination of a new equivalent of anionic ligand allows for the RLT complex to be regenerated, making this strategy inherently compatible with catalysis. Building on this, one of the most important examples of catalytic RLT can be found in the human

Unravelling a trichloroacetic acid-catalyzed cascade access to benzo[f]chromeno[2,3-h]quinoxalinoporphyrins

• Chandra Sekhar Tekuri,
• Pargat Singh and
• Mahendra Nath

Beilstein J. Org. Chem. 2023, 19, 1216–1224, doi:10.3762/bjoc.19.89

• spectroscopy. The preliminary photophysical results revealed a significant red-shift in their absorption and emission spectra as compared to the meso-tetrakis(4-methylphenyl)porphyrins due to the extended π-conjugation. Keywords: bathochromic shift; benzo[f]chromeno[2,3-h]quinoxalinoporphyrins; catalysis

• ; multicomponent synthesis; one-pot reaction; trichloroacetic acid; Introduction π-Conjugated porphyrin macrocycles are known for their applications in numerous areas ranging from oxygen transport, photosynthesis, catalysis and medicine [1][2][3]. In the past several years, diverse organic scaffolds have been

Enabling artificial photosynthesis systems with molecular recycling: A review of photo- and electrochemical methods for regenerating organic sacrificial electron donors

• Grace A. Lowe

Beilstein J. Org. Chem. 2023, 19, 1198–1215, doi:10.3762/bjoc.19.88

• it will not be covered in this review. Most molecular components for photoreduction catalysis are not being developed or optimized with sacrificial electron donors that can be recycled. This means that the conditions must be reoptimized if redox mediators or other recyclable donors need to be used to

• donors used in photoreduction catalysis for artificial photosynthesis. Specifically, organic electron or hydride donors usually applied in molecular photocatalysis. 2. Survey the literature from different fields and present a sample of potentially recyclable electron donors for artificial photosynthesis

• close to the final catalysis conditions as possible. Once candidate donors have been identified using their oxidation potential, their quenching behavior and the effect on the photocatalytic performance can be tested. To help identify potential recyclable replacements for sacrificial donors such as

Exploring the role of halogen bonding in iodonium ylides: insights into unexpected reactivity and reaction control

• Carlee A. Montgomery and
• Graham K. Murphy

Beilstein J. Org. Chem. 2023, 19, 1171–1190, doi:10.3762/bjoc.19.86

• have been feasible. In 1989, Moriarty was investigating the intramolecular cyclopropanation of 10 under copper-catalysis, presuming that the reaction would proceed through a metallocarbene intermediate [113]. However, a control experiment showed the reaction to also be viable without catalyst, from

• conditions, and offered a related mechanistic proposal (Figure 5, right) for the formation of 20 [110]. Given that their reaction proceeded almost equally well under metal-free conditions as under Rh2(OAc)4 catalysis (3.5 h, 40 °C, 31% 20), and that free carbene formation was unlikely at this temperature

Selective and scalable oxygenation of heteroatoms using the elements of nature: air, water, and light

• Damiano Diprima,
• Hannes Gemoets,
• Stefano Bonciolini and
• Koen Van Aken

Beilstein J. Org. Chem. 2023, 19, 1146–1154, doi:10.3762/bjoc.19.82

• phosphine oxide, and selenides to selenoxides. Sulfoxide, phosphine oxide, and selenoxide-containing molecules have diverse applications in the pharmaceutical industry [10], as chiral auxiliaries or as ligands for asymmetric metal catalysis [11], and in materials such as polymers [12][13] and flame

• retardants [14]. Sulfoxides are prominent pharmaceutical ingredients, while phosphine oxides improve solubility of corresponding compounds [15] and have applications in catalysis and materials science [16]. Selenoxides find use as oxygen transfer agents and donor ligands in metal catalysis and organic

• comparative study between the electrochemical and the photoredox pathway, using the exact same chemical matrix, is not yet described. Intrigued by this, we decided to investigate the oxidation of sulfides both via electrochemistry and photoredox catalysis using thioanisole as benchmark substrate. Initially

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

• Mattia Lepori Simon Schmid Joshua P. Barham Fakultät für Chemie und Pharmazie, Universität Regensburg, Universitatsstraße 31, 93040 Regensburg, Germany 10.3762/bjoc.19.81 Abstract Photoredox catalysis (PRC) is a cutting-edge frontier for single electron-transfer (SET) reactions, enabling the

• feedstocks, and scalability up to gram scales in continuous flow. This review provides comparisons between the two techniques (multi-photon photoredox catalysis and PEC) to help the reader to fully understand their similarities, differences and potential applications and to therefore choose which method is

• the most appropriate for a given reaction, scale and purpose of a project. Keywords: consecutive photoinduced electron transfer; electro-activated photoredox catalysis; photoelectrochemistry; photoredox catalysis; radical ions; Review 1 Introduction Owing to the unique reactivity patterns of free

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

• the tremendous progress in organic chemistry over the last few decades, metal catalysis has been increasingly and successfully replaced by organocatalysis, i.e., accelerating the rate of chemical transformations by using small organic molecules as catalysts. Although being discovered more than 100