Synthesis and properties of 6-alkynyl-5-aryluracils

• Ruben Manuel Figueira de Abreu,
• Till Brockmann,
• Alexander Villinger,
• Peter Ehlers and
• Peter Langer

Beilstein J. Org. Chem. 2024, 20, 898–911, doi:10.3762/bjoc.20.80

• , only the double-substituted product could be found. No reaction was observed when the reaction temperature was lowered to 0 °C. This could be due to the double activation of the 5-position, despite the fact that bromine is a better leaving group than chlorine. Both positions might be influenced by the

• functional groups adjacent to them, due to withdrawing effects. Chlorine has a stronger electron-withdrawing effect than bromine, so the electrophilic character of the 6-position should be higher than that of the 5-position. However, it is unlikely to be the only reason for the formation of just one

• carried out by application of the Suzuki–Miyaura cross-coupling. The optimization was carried out with 3a as the model compound (Table 1). The starting material 3a is a sterically hindered system in which the bromine is only partially accessible, due to the large residue. This could be the reason for the

Ortho-ester-substituted diaryliodonium salts enabled regioselective arylocyclization of naphthols toward 3,4-benzocoumarins

• Ke Jiang,
• Cheng Pan,
• Limin Wang,
• Hao-Yang Wang and
• Jianwei Han

Beilstein J. Org. Chem. 2024, 20, 841–851, doi:10.3762/bjoc.20.76

• generally moderate to good yields of 22–83% (Table 2, entries 1–17). These substituents included halogen (Br), methyl, phenyl, aldehyde, ester, and methoxy groups, all of which were compatible with the reaction conditions. Notably, compounds 3ab, 3ah, 3aj, 3am and 3ap bearing bromine are very useful modules

Entry to new spiroheterocycles via tandem Rh(II)-catalyzed O–H insertion/base-promoted cyclization involving diazoarylidene succinimides

• Alexander Yanovich,
• Anastasia Vepreva,
• Ksenia Malkova,
• Grigory Kantin and
• Dmitry Dar’in

Beilstein J. Org. Chem. 2024, 20, 561–569, doi:10.3762/bjoc.20.48

• ) or a bromine atom. These transformations yield spiro-annulated O-heterocycles with succinimide ring, namely spiro-Δα,β-butenolides 2 and 3, tetrahydrofurans 4 and benzopyrans 5 (Scheme 1). Fragments of these oxygen-containing spiro-conjugated heterocycles are part of many important drugs and natural

• reaction products using diazo reagent 1b as an example, but we failed to observe the formation of spirocyclic cyclization products as a result of intramolecular substitution of the bromine atom (Scheme 7). For example, during the attempted cyclization of compound 18, obtained from 2-(bromomethyl)benzoic

• from each of the bromo-substituted alcohols used by us have two main pathways of transformation under the action of base: 1) exo-tet cyclization with substitution of the bromine atom and formation of the spirocycle, and 2) migration of the exocyclic double C=C bond into the imide cycle (the process is

Synthesis and biological profile of 2,3-dihydro[1,3]thiazolo[4,5-b]pyridines, a novel class of acyl-ACP thioesterase inhibitors

• Jens Frackenpohl,
• David M. Barber,
• Guido Bojack,
• Birgit Bollenbach-Wahl,
• Ralf Braun,
• Rahel Getachew,
• Sabine Hohmann,
• Kwang-Yoon Ko,
• Karoline Kurowski,
• Bernd Laber,
• Rebecca L. Mattison,
• Thomas Müller,
• Anna M. Reingruber,
• Dirk Schmutzler and
• Andrea Svejda

Beilstein J. Org. Chem. 2024, 20, 540–551, doi:10.3762/bjoc.20.46

• proceeded cleanly under mild conditions, using the corresponding acyl chloride together with triethylamine as a suitable base in DCM. Furthermore, we evaluated the tolerance of [1,3]thiazolo[4,5-b]pyridines 12a–c, containing a bromine atom, towards the optimized B(C6F5)3-mediated reduction. In good

(E,Z)-1,1,1,4,4,4-Hexafluorobut-2-enes: hydrofluoroolefins halogenation/dehydrohalogenation cascade to reach new fluorinated allene

• Nataliia V. Kirij,
• Andrey A. Filatov,
• Yurii L. Yagupolskii,
• Sheng Peng and
• Lee Sprague

Beilstein J. Org. Chem. 2024, 20, 452–459, doi:10.3762/bjoc.20.40

• -hexafluorobut-2-ene and an oxalamide hydrazone [17]. In the present study, we investigated the reactions of commercially available butenes 1a,b with halogens, as well as subsequent transformations of the resulting compounds. Results and Discussion In 1952 Haszeldine found that the reaction of bromine with (E

• bromine in the same manner under the influence of ultraviolet irradiation or sunlight with the formation of 2,3-dibromo-1,1,1,4,4,4-hexafluorobutane (2) in 95% yield (Scheme 1). The only difference was that under UV irradiation, the reaction proceeded faster. In both cases, product 2 represented a mixture

• important synthons, which are widely used in agrochemicals, pharmaceuticals and other fields [24][25][26]. Fluoroorganic lithium and Grignard reagents have been obtained by the metalation reactions of organofluorine compounds containing bromine and iodine atoms with alkyllithium and Grignard reagents

Synthesis of π-conjugated polycyclic compounds by late-stage extrusion of chalcogen fragments

• Aissam Okba,
• Pablo Simón Marqués,
• Kyohei Matsuo,
• Naoki Aratani,
• Hiroko Yamada,
• Gwénaël Rapenne and
• Claire Kammerer

Beilstein J. Org. Chem. 2024, 20, 287–305, doi:10.3762/bjoc.20.30

• naphthyl substituents carrying each an alkyne moiety on the ortho position. Ring expansion of both thiophene units in 19 was then triggered by platinum catalysis to generate the corresponding thiopyrans, and finally the bromine atoms located on the latter rings were exploited for the ring closure of the

Substitution reactions in the acenaphthene analog of quino[7,8-h]quinoline and an unusual synthesis of the corresponding acenaphthylenes by tele-elimination

• Ekaterina V. Kolupaeva,
• Narek A. Dzhangiryan,
• Alexander F. Pozharskii,
• Oleg P. Demidov and
• Valery A. Ozeryanskii

Beilstein J. Org. Chem. 2024, 20, 243–253, doi:10.3762/bjoc.20.24

• , dipyridoacenaphthene 5 is not brominated by molecular bromine in chloroform or acetic acid. The action of the NBS–DMF system, previously proposed for the electrophilic bromination of alkylaromatic compounds [26], leaves substrate 5 unchanged at room temperature, and when heated to 75 °C for several days causes its

• ratio. It should be recalled here that tele-elimination refers to the cleavage of molecular fragments located further than in the vicinal positions (at least three to five carbons between the hydrogen and bromine atoms in the case of 15 to give 16). This rare transformation usually results in the

• and in the protonated form. Thus, the unusual products of base treatment on dibromide 15 can be formally considered as a result of tele-elimination of bromine with the simultaneous shift of the two hydrogen atoms from the CH2CH2 bridge to positions 5(8) of the naphthalene system (formation of

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

• ) were measured. The significant difference in the quantum yield values between the compounds was attributed to the increase in the population of triplet excited states because of spin–orbit coupling by bromine atoms. On the contrary with previous studies, it was found that the effect of proton and

Copper-promoted C5-selective bromination of 8-aminoquinoline amides with alkyl bromides

• Changdong Shao,
• Chen Ma,
• Li Li,
• Jingyi Liu,
• Yanan Shen,
• Chen Chen,
• Qionglin Yang,
• Tianyi Xu,
• Zhengsong Hu,
• Yuhe Kan and
• Tingting Zhang

Beilstein J. Org. Chem. 2024, 20, 155–161, doi:10.3762/bjoc.20.14

• and organic bromine-containing compounds such as Br2, CuBr, CuBr2, LiBr, NaBr, KBr, HBr, NH4Br, and tetrabutylammonium bromide (TBAB) as halogen sources have been realized (Scheme 1, reaction 1) [11][12][13][14][15][16][17][18][19][20]. Another category of extensively used bromination reagents are

• bromine source in combination with Selectfluor® (Scheme 1, reaction 3) [29]. Despite significant progress in this area, most of these methodologies still suffer from the use of external oxidants, complex reaction equipment, and expensive and/or toxic halogen sources, which limit the practicality for large

• reaction of 8-aminoquinoline amides using activated and unactivated alkyl bromides as the bromine source (Scheme 1, reaction 4). Results and Discussion At the beginning of this investigation, N-(quinolin-8-yl)benzamide (1a) and ethyl bromoacetate (2a) were selected as model substrates to screen the

Multi-redox indenofluorene chromophores incorporating dithiafulvene donor and ene/enediyne acceptor units

• Christina Schøttler,
• Kasper Lund-Rasmussen,
• Line Broløs,
• Philip Vinterberg,
• Ema Bazikova,
• Viktor B. R. Pedersen and
• Mogens Brøndsted Nielsen

Beilstein J. Org. Chem. 2024, 20, 59–73, doi:10.3762/bjoc.20.8

• compound is shown below, in which the hydrogen atoms are omitted for clarity. Atoms are colored grey (carbon), white (hydrogen), brown (bromine), pale-yellow (silicon). Labels of bonds within five-membered ring. Synthesis of IF-DTF ketones 9–12 and dimer 13. Further functionalization of the IF-DTF ketone

N-Boc-α-diazo glutarimide as efficient reagent for assembling N-heterocycle-glutarimide diads via Rh(II)-catalyzed N–H insertion reaction

• Grigory Kantin,
• Pavel Golubev,
• Alexander Sapegin,
• Alexander Bunev and
• Dmitry Dar’in

Beilstein J. Org. Chem. 2023, 19, 1841–1848, doi:10.3762/bjoc.19.136

• yield. As a side process, а carbenoid's repeated attack at the 6-position of the tetrahydroquinoline ring of compound 6x was observed according to NMR data. Introducing a bromine atom to block the 6-position led to a significant increase in the target product 6y yield. The decomposition of diazo reagent

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

• nitroarenes 48 (Scheme 22). The protocol demonstrated excellent tolerance towards a wide range of reducible functional groups, including halogens (such as chlorine, bromine, and even iodine), aldehydes, ketones, carboxyl groups, and cyano groups. Iodination Alkyl iodide is considered to be the most reactive

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

• -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

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

• . explored the modulation of optoelectrochemical properties and thermal characteristics of pyridopyrazino[2,3-b]indole-based Qx46 series with varying substituents, i.e., bromine, chlorine, methyl and nitro group. Their study revealed inbuilt ICT and aggregation-induced emission (AIE) effects, forming

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

• protective gas atmosphere, leads to slow decomposition. Therefore, storage at low temperature in a dark vial is strongly recommended. Upon using 2,4-dibromoaniline (1c) as the substrate and an excess of phenylacetylene (2a), both carbon–bromine bonds are transformed in the alkynylation step affording the

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

• mesylated to 29.2. Then, a bromine atom was introduced via a nucleophilic substitution with LiBr in acetone to form 29.3. Finally, the primary bromide was used to introduce different ammonium salts as illustrated with compound 29.4. A variation of this sequence consisted in placing an ether function in

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

• Guthrie in the 1860s as an attraction between ammonia and molecular iodine [19]. The 20th century saw halogen bonding extended to organohalides such as diiodoacetylene [25][26], and also saw the first X-ray crystallographic evidence of a ‘halogen molecular bridge’ between molecular bromine and 1,4-dioxane

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

• enabling controlled bond activations [45]. Regarding the reductive C–C arylation, the application of the xanthene dye rhodamine 6G (Rh-6G) as a catalyst for the reduction of heteroarenes bearing two or three bromine atoms (e.g., 6) under irradiation with green light (λ = 530 nm) gave monosubstituted

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

• for those ‘revised structures’ [3]. This paper impelled us to revisit our original work and assess the validity of Novitskiy and Kutateladze’s claim whether our assignment was indeed wrong. Results and Discussion In 2008 we investigated the electrophilic addition of bromine to 1 (7-endo-bicyclo[2.2.1

• elucidated the exact configuration of compound 6. The symmetrical structure of 6 could be characterized easily because of its four-line 13C NMR spectrum. However, on the basis of 13C NMR data alone we were not able to distinguish between possible symmetrical tribromides. The configurations of the bromine

• observation provides evidence that the H2 and H3 protons have the exo-configuration. In other words, the adjacent bromine atoms have the endo-configuration (Supporting Information File 1). Upon irradiation at the resonance frequency (4.97 ppm) of the protons H2 and H3 no change is observed in the resonance

Improving the accuracy of ³¹P NMR chemical shift calculations by use of scaling methods

• William H. Hersh and
• Tsz-Yeung Chan

Beilstein J. Org. Chem. 2023, 19, 36–56, doi:10.3762/bjoc.19.4

Redox-active molecules as organocatalysts for selective oxidative transformations – an unperceived organocatalysis field

• Elena R. Lopat’eva,
• Igor B. Krylov,
• Dmitry A. Lapshin and
• Alexander O. Terent’ev

Beilstein J. Org. Chem. 2022, 18, 1672–1695, doi:10.3762/bjoc.18.179

• enantioselective hydroxylation of benzylic positions was achieved using a chiral aryl iodide mediator [148] (Scheme 34). At the first stage, under the action of m-CPBA and sodium bromide an active form of the catalyst ArI3-Br is formed, in which the iodine–bromine bond is cleaved homolytically under visible light

Simple synthesis of multi-halogenated alkenes from 2-bromo-2-chloro-1,1,1-trifluoroethane (halothane)

• Yukiko Karuo,
• Atsushi Tarui,
• Kazuyuki Sato,
• Kentaro Kawai and
• Masaaki Omote

Beilstein J. Org. Chem. 2022, 18, 1567–1574, doi:10.3762/bjoc.18.167

• Yukiko Karuo Atsushi Tarui Kazuyuki Sato Kentaro Kawai Masaaki Omote Faculty of Pharmaceutical Sciences, Setsunan University, 45-1 Nagaotoge-cho, Hirakata, Osaka 573-0101, Japan 10.3762/bjoc.18.167 Abstract A series of aryl fluoroalkenyl ethers that contain chlorine and bromine as well as

• difluoroalkyl ethers (1), along with small amounts of fluoroalkenyl ethers (2), which were obtained from 1 via an E2-elimination mechanism (Scheme 1B) [14][15]. The fluoroalkenyl group in 2 is a potentially useful moiety that could participate in cross-coupling reactions for replacement of the bromine atom with

• bond between the bromine and chlorine atoms in 1. Extra KOH was added to improve deprotonation, but the yield of 2a was still low (Table 1, entries 2 and 3). Changing the solvent from THF to DME and increasing the temperature to 80 °C slightly improved the yield of 2a to 19% (Table 1, entry 4

Using UHPLC–MS profiling for the discovery of new sponge-derived metabolites and anthelmintic screening of the NatureBank bromotyrosine library

• Sasha Hayes,
• Aya C. Taki,
• Kah Yean Lum,
• Joseph J. Byrne,
• Merrick G. Ekins,
• Robin B. Gasser and
• Rohan A. Davis

Beilstein J. Org. Chem. 2022, 18, 1544–1552, doi:10.3762/bjoc.18.164

• time. 5-Debromopurealidin H (1) was isolated as a stable yellow film. The LRESIMS of 1 showed 1:1 ion cluster peaks at m/z 382/384 [M + H]+ and 380/382 [M − H]−, indicating the presence of one bromine atom [16]. Furthermore, a molecular formula of C14H17BrN5O3 was assigned following analysis of the 1D

• data with related previously reported purealidins [19]. While no HMBC correlations were identified for these exchangeable proton signals, the presence of a phenol was further supported by a bathochromic shift that was seen in the UV spectrum of 1 upon addition of base [20]. The bromine atom and phenol

An alternative C–P cross-coupling route for the synthesis of novel V-shaped aryldiphosphonic acids

• Stephen J. I. Shearan,
• Enrico Andreoli and
• Marco Taddei

Beilstein J. Org. Chem. 2022, 18, 1518–1523, doi:10.3762/bjoc.18.160

• explains the high phosphite-to-bromine ratio, which in our case is higher than all the other routes, since the phosphite itself acts as the solvent as well as being a reactant. If this ratio was lower, there would be a considerable drop in the reaction rate towards the end and would likely lead to

Mechanochemical synthesis of unsymmetrical salens for the preparation of Co–salen complexes and their evaluation as catalysts for the synthesis of α-aryloxy alcohols via asymmetric phenolic kinetic resolution of terminal epoxides

• Shengli Zuo,
• Shuxiang Zheng,
• Jianjun Liu and
• Ang Zuo

Beilstein J. Org. Chem. 2022, 18, 1416–1423, doi:10.3762/bjoc.18.147

• due to the strong electron-withdrawing effect of bromine, enhancing the electrophilic property of bromo-substituted salicylaldehyde. Because of the poor solubility in the eluent, the yield of dichloro-containing 1c (88%) was lower than 1a after isolating by column chromatography. This was also found