Benzoimidazolium-derived dimeric and hydride n-dopants for organic electron-transport materials: impact of substitution on structures, electrochemistry, and reactivity

• Swagat K. Mohapatra,
• Khaled Al Kurdi,
• Samik Jhulki,
• Georgii Bogdanov,
• John Bacsa,
• Maxwell Conte,
• Tatiana V. Timofeeva,
• Seth R. Marder and
• Stephen Barlow

Beilstein J. Org. Chem. 2023, 19, 1651–1663, doi:10.3762/bjoc.19.121

• by various quinone derivatives [63]. For both mechanisms, the first steps are typically rate determining and thus, in general, the rate law is: where k1 and k2 are rate constants for the first steps of the “cleavage first” and “ET-first” pathways respectively, k1 being negligible in the case of

• the rise in VII•– absorption is neither zero-order nor first-order in VII, consistent with both mechanisms contributing, as previously demonstrated by more extensive investigations in the case of 1c2, 1d2, and (RhCp*Cp)2 [14][61]. Thus, the Y = alkyl derivative (1h2, “ET-first” only) appears to be

• more strongly bonded than its Y = aryl counterparts (1b2, 1g2, both mechanisms), consistent with previous DFT calculations for 1b2 and 1e2 (ΔUdiss = 163 and 210 kJ mol–1, respectively) and with the expected impact of the different Y substituents on monomer radical stability. In addition, the reaction

Sulfur-containing spiroketals from Breynia disticha and evaluations of their anti-inflammatory effect

• Ken-ichi Nakashima,
• Naohito Abe,
• Masayoshi Oyama,
• Hiroko Murata and
• Makoto Inoue

Beilstein J. Org. Chem. 2023, 19, 1604–1614, doi:10.3762/bjoc.19.117

• Freund's adjuvant-induced arthritis in rats [12]. However, the molecular mechanisms of these anti-inflammatory effects have not been investigated. In our ongoing search for bioactive natural products, we have isolated three new spiroketals – breynin J (1), epibreynin J (2), and probreynogenin (3) – and

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

• considered to have two mechanisms, degenerative transfer and reversible termination, which are comparable to RAFT and NMP, respectively (Scheme 7) [70]. Iodine transfer polymerization (ITP) is also a commonly used degenerate chain-transfer method. Its origin can be traced back to the 1970s [71] and it is

• using benzophenone. Depolymerization mechanism of common photoresists. (a) A possible mechanism of radiation decomposition of poly(methyl methacrylate). (b) A proposed mechanism of simultaneous radical/cationic decomposition of poly(olefin sulfone) upon radiation [197]. Proposed mechanisms of

Unraveling the role of prenyl side-chain interactions in stabilizing the secondary carbocation in the biosynthesis of variexenol B

• Moe Nakano,
• Rintaro Gemma and
• Hajime Sato

Beilstein J. Org. Chem. 2023, 19, 1503–1510, doi:10.3762/bjoc.19.107

• . Several terpene cyclizations with an exomethylene group are known, such as with caryolene and crotinsulidane diterpenoids, and the reaction mechanisms have been analyzed [27][28][29][30]. It would be interesting to see how the exomethylene group reacts in the cyclization of variexenol B. In this study, we

• follow similar reaction mechanisms, however, when comparing path a and path b, the most striking energy difference is in the step from IM2a/b to IM3a/b (Figure 2B). The energy barrier of this step is 6.3 kcal/mol for path a, whereas 13.6 kcal/mol for path b, with a difference of 7.3 kcal/mol. Although

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

• is no need to use a metal catalyst, base, or additive. N-(Sulfenyl)succinimide/phthalimide acted as an active electrophilic sulfur source, acted in the reaction mechanisms. However, mechanistic studies need further exploration to define a valid reaction pathway. Therefore, we believe that the use of

Cyclization of 1-aryl-4,4,4-trichlorobut-2-en-1-ones into 3-trichloromethylindan-1-ones in triflic acid

• Vladislav A. Sokolov,
• Andrei A. Golushko,
• Irina A. Boyarskaya and
• Aleksander V. Vasilyev

Beilstein J. Org. Chem. 2023, 19, 1460–1470, doi:10.3762/bjoc.19.105

• mechanisms for the cyclization of compounds 1 and 2 into indanones 3 in TfOH (Scheme 7). Protonation of the carbonyl oxygen of enone 2 gives rise to cation B which is followed by cyclization into indanone 3 through mesomeric form B'. The hydroxy ketone 1 is protonated at the oxygen atoms leading to cation A

• -4,4,4-trichlorobut-2-en-1-ones 2 into 3-trichloromethylindan-1-ones 3 in TfOH. Cyclization of 1-aryl-4,4,4-trichloro-3-hydroxybutan-1-ones 1 into 3-trichloromethylindan-1-ones 3 in TfOH. Plausible mechanisms for the cyclization of compounds 1 and 2 into indanones 3 in TfOH. Transformations of hydroxy

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

• modulation of membrane proteins that represent a pertinent strategy for some diseases like cancers. Beside the use of synthetic ether lipids for the prevention or the treatment of cancers via different mechanisms, it must be noted that some synthetic ether lipids (e.g., Ino-C2-PAF) have also the ability to

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

• Cu-catalyzed oxidative coupling reactions [43]. However, due to complex mechanisms, Cu-catalyzed C–H functionalization reactions developed only slowly in the last decade. Since recently the Cu-catalyzed oxidative coupling has emerged as a powerful synthetic strategy due to the development of CDC

• metal-triggered oxidation of the ether substrate to obtain the corresponding radical or oxonium ion as the key intermediate to obtain the final coupling product. Subsequently, some novel Co-catalyzed coupling mechanisms have been proposed. In 2016, Lu et al. reported that the Co/TBHP catalyst oxidation

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

• photosynthesis research not only because they occur in biological photosynthesis but also because the PCET can circumvent unstable one electron-reduced intermediates. This makes PCET mechanisms well-suited for complex multielectron reactions required to transfer electrons and protons from water onto carbon

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

• provides an overview of the reactions of iodonium ylides in which halogen bonding has been invoked. Herein, we summarize key discoveries and mechanistic proposals from the early iodonium ylide literature that invoked halogen bonding-type mechanisms, as well as recent reports of reactions between iodonium

• cyclopropane 22a. Interestingly, Hadjiarapoglou also revisited their investigation of iodonium ylide cycloadditions and their associated mechanisms [120], using diphenylketene as a new reaction partner with dimedone iodonium ylide 6 (analogous to earlier work reported by Koser in 1975 [9]). Investigations by

• , their scope has recently expanded to include X–H insertions based on single electron transfer (SET) mechanisms, cycloadditions based on blue LED photochemistry and radiofluorinations of unactivated arene motifs. In these reports, mechanistic proposals commonly treat the hypervalent iodine atom as being

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

The effect of dark states on the intersystem crossing and thermally activated delayed fluorescence of naphthalimide-phenothiazine dyads

• Liyuan Cao,
• Xi Liu,
• Xue Zhang,
• Jianzhang Zhao,
• Fabiao Yu and
• Yan Wan

Beilstein J. Org. Chem. 2023, 19, 1028–1046, doi:10.3762/bjoc.19.79

• intersystem crossing (rISC) is slow, without coupling with an approximate 3LE state. These studies are useful for an in-depth understanding of the photophysical mechanisms of the TADF emitters, as well as for molecular structure design of new electron donor–acceptor TADF emitters. Keywords: charge-transfer

• [38][39][40][41][42][43][44] and, more recently, time-resolved electron paramagnetic resonance (TREPR) spectroscopy [33][39][44][45][46] were also applied to study TADF mechanisms, but the examples are limited. Therefore, much room is left for studies of the photophysical mechanism of the TADF

• state energy), while keeping other factors intact to a large extent (e.g., the LE state energy). This is an important advantage for the study of complicated photophysical mechanisms involved in TADF processes. The syntheses of the dyads are based on the known derivatization chemistry of NI and PTZ

Intermediates and shunt products of massiliachelin biosynthesis in Massilia sp. NR 4-1

• Till Steinmetz,
• Blaise Kimbadi Lombe and
• Markus Nett

Beilstein J. Org. Chem. 2023, 19, 909–917, doi:10.3762/bjoc.19.69

• into the cell through membrane receptors and transporters. Eventually, the bound metal is released through reductive or hydrolytic mechanisms [2]. In the past years, β-proteobacteria have received increasing attention as producers of siderophores with interesting chemical features. For instance

• underlie discrete regulation mechanisms, which explains their context-dependent production [27]. The examples of P. aeruginosa and B. anthracis suggest that siderophore biosynthesis sometimes requires specific triggers beyond iron deficiency, which may not be met under laboratory conditions. The six

Light-responsive rotaxane-based materials: inducing motion in the solid state

• Adrian Saura-Sanmartin

Beilstein J. Org. Chem. 2023, 19, 873–880, doi:10.3762/bjoc.19.64

• Photoresponsive rotaxane discrete crystals A complete understanding of the crystallization mechanisms accompanied by a rational design can lead to the obtention of crystalline molecular materials which allow the dynamics of the counterparts to take place [35][36][37]. Indeed, the motion of the cyclic counterparts

Pyridine C(sp²)–H bond functionalization under transition-metal and rare earth metal catalysis

• Haritha Sindhe,
• Malladi Mounika Reddy,
• Karthikeyan Rajkumar,
• Akshay Kamble,
• Amardeep Singh,
• Anand Kumar and
• Satyasheel Sharma

Beilstein J. Org. Chem. 2023, 19, 820–863, doi:10.3762/bjoc.19.62

• the mechanisms involved. Keywords: C–H functionalization; heterocycles; pyridine; rare earth metal; transition-metal-catalyzed; Introduction Pyridine, one of the most important azaheterocyclic scaffolds, is found in a diverse range of bioactive natural products, pharmaceuticals, and functional

Synthesis of substituted 8H-benzo[h]pyrano[2,3-f]quinazolin-8-ones via photochemical 6π-electrocyclization of pyrimidines containing an allomaltol fragment

• Constantine V. Milyutin,
• Andrey N. Komogortsev,
• Boris V. Lichitsky,
• Mikhail E. Minyaev and
• Valeriya G. Melekhina

Beilstein J. Org. Chem. 2023, 19, 778–788, doi:10.3762/bjoc.19.58

• of the methanol molecule occurs only for intermediate A and is not observed for product 11. It is important to emphasize that earlier, when discussing the mechanisms of the 6π-electrocyclization of various terarylenes accompanied by subsequent elimination of small molecules, we assumed a [1,9]-H

Bromination of endo-7-norbornene derivatives revisited: failure of a computational NMR method in elucidating the configuration of an organic structure

• Demet Demirci Gültekin,
• Arif Daştan,
• Yavuz Taşkesenligil,
• Cavit Kazaz,
• Yunus Zorlu and
• Metin Balci

Beilstein J. Org. Chem. 2023, 19, 764–770, doi:10.3762/bjoc.19.56

• have developed a machine learning-augmented DFT method for computational NMR, DU8ML, for fast and ‘accurate’ computational approaches [2]. They applied this computational method to a number of previously published organic compounds and claimed to have revised some structures and proposed new mechanisms

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

• propagate further. A subsequent migratory insertion into a second azaspirotricyclic alkene furnishes 183. Finally, the anion from the catalyst attacks 183 causing a ring opening, forming the final product 178d and regenerating the Rh(I) catalyst. Keeping with other mechanisms, the Rh(I) may also undergo an

Transition-metal-catalyzed C–H bond activation as a sustainable strategy for the synthesis of fluorinated molecules: an overview

• Louis Monsigny,
• Floriane Doche and
• Tatiana Besset

Beilstein J. Org. Chem. 2023, 19, 448–473, doi:10.3762/bjoc.19.35

• amide derived from 8-aminoquinoline 13e (Scheme 6, 13 examples, up to 75% yield). In this study, two mechanisms were reported. The first one suggested that a palladacycle C is formed after the irreversible chelation of the 2-phenylpyridine substrate with palladium, which is the rate-determining step

Asymmetric synthesis of a stereopentade fragment toward latrunculins

• Benjamin Joyeux,
• Antoine Gamet,
• Nicolas Casaretto and
• Bastien Nay

Beilstein J. Org. Chem. 2023, 19, 428–433, doi:10.3762/bjoc.19.32

• presence of DIPEA, performed well in the aldol reaction to furnish product 21 in 55% yield with a good dr of 91:9 (Scheme 3). The stereocontrol of the reaction could be envisaged through two principal mechanisms. A remote stereocontrol by the nucleophile could first be expected [29], through a 1,5-anti

Group 13 exchange and transborylation in catalysis

• Dominic R. Willcox and
• Stephen P. Thomas

Beilstein J. Org. Chem. 2023, 19, 325–348, doi:10.3762/bjoc.19.28

• ). Thomas and Gunanathan independently reported the borane-catalysed double hydroboration of nitriles using either Me2S·BH3 or H-B-9-BBN, respectively, as the catalyst and HBpin as the turnover reagent (Scheme 9) [72][73]. Both reports proposed similar mechanisms for the Me2S·BH3- and H-B-9-BBN-catalysed

• species 93, followed by Al‒O/B‒H exchange with HBpin to give the alkoxy boronic ester 94 and regenerate the aluminium hydride 92 (Scheme 23). Several aluminium hydride compounds have been reported as competent carbonyl hydroboration catalysts, with proposed mechanisms similar to Roesky’s initial report

Germacrene B – a central intermediate in sesquiterpene biosynthesis

• Houchao Xu and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2023, 19, 186–203, doi:10.3762/bjoc.19.18

• ) The reprotonation of 1 at C-4 potentially leads to four stereoisomers of cation K, B) reprotonation at C-10 can result in four stereoisomers of L. The sesquiterpenes derived from cations K1, K2 and K4. A) Mechanisms of formation for compounds 53–56, B) pyrolysis of 58 to 53. The sesquiterpenes derived

• from cations L1–L4. A) Mechanisms of formation for compounds 54, 56, 59 and 60, B) dehydration of 61 to 56, C) oxidation of 56 to 62, D) dehydration of 63 to 60 and 64 (no yields were given in the original reports for the synthetic transformations shown in this Scheme).

Total synthesis of insect sex pheromones: recent improvements based on iron-mediated cross-coupling chemistry

• Eric Gayon,
• Guillaume Lefèvre,
• Olivier Guerret,
• Adrien Tintar and
• Pablo Chourreu

Beilstein J. Org. Chem. 2023, 19, 158–166, doi:10.3762/bjoc.19.15

• mechanisms to help regulate/balance the populations of harmful species rather than eradicating them) based on the use of insect pheromones [2][3][4][5] is an eco-friendly solution for the protection of a wide range of crops and plants against pests. Indeed, those chemical mediators, which are emitted by

Insight into oral amphiphilic cyclodextrin nanoparticles for colorectal cancer: comprehensive mathematical model of drug release kinetic studies and antitumoral efficacy in 3D spheroid colon tumors

• Sedat Ünal,
• Gamze Varan,
• Juan M. Benito,
• Yeşim Aktaş and
• Erem Bilensoy

Beilstein J. Org. Chem. 2023, 19, 139–157, doi:10.3762/bjoc.19.14

• assessments of this topic [9]. Release kinetics study The in vitro release profiles of CPT-loaded amphiphilic cyclodextrin nanoparticles were fitted with a variety of kinetic models, and the release mechanisms, which are illuminating markers for novel drug delivery systems, were mathematically investigated

• two different colon tumors to differ from each other is the origin of the cells. The genome-transcriptome mapping investigation revealed that despite having two separate origins, the CT26 cell has characteristics similar to human primary colorectal cancers in terms of drug resistance mechanisms, gene

• discovered that inhibiting E-cadherins, which are adhesion molecules that provide intracellular connection, increases the sensitivity of 3D colon cancer tumors to 5-fluorouracil, paclitaxel, vinblastine, and etoposide [67]. In the literature, uptake mechanisms of nanoparticles and free drugs in 2D and 3D

Organophosphorus chemistry: from model to application

• György Keglevich

Beilstein J. Org. Chem. 2023, 19, 89–90, doi:10.3762/bjoc.19.8

• chemistry and beyond. Quantum chemical calculations are a great support for organic chemists when exploring structures, reactivities, and mechanisms. In this thematic issue, the Diels–Alder cycloaddition of 2-phosphaindolizine, 1-aza-2-phosphaindolizine, 3-aza-2-phosphaindolizine, and 1,3-diaza-2