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

• groups as measured by rates of Michael addition [52]. This suggests that in fact nitrogen nucleophilicity alone is not the most relevant factor since sulfonamides react much slower in hydroamination. Sulfonamide N–H bonds are significantly more acidic than urea, amide and carbamate N–H bonds (16.1 versus

• ; more basic carbonyls react faster and undergo N–H/D exchange faster in the presence of gold suggesting gold nucleophile interactions drive reactivity. • Rate inhibition is observed at the highest concentrations of urea 1a and amide 1b; the increasing basicity would slow down any acid mediated processes

Discovery of unguisin J, a new cyclic peptide from Aspergillus heteromorphus CBS 117.55, and phylogeny-based bioinformatic analysis of UngA NRPS domains

• Sharmila Neupane,
• Marcelo Rodrigues de Amorim and
• Elizabeth Skellam

Beilstein J. Org. Chem. 2024, 20, 321–330, doi:10.3762/bjoc.20.32

• of several catalytic domains organized into modules. Typically, a module possesses an adenylation (A) domain for selecting and activating amino- or keto acids, a thiolation (T) domain for shuttling intermediates between catalytic domains, and a condensation (C) domain that catalyzes amide or ester

• . The 1H and 13C NMR spectra of 1 revealed the presence of seven amide NH signals between δH 7.43 and 8.44 ppm supported by the amide carbonyl signals at δC 173.1, 172.6, 172.6, 172.1, 172.1, 171.1 and 171.0 ppm (Table 1). An additional NH signal at δH 10.82 ppm and four aromatic signals at δH 7.50

Synthesis of spiropyridazine-benzosultams by the [4 + 2] annulation reaction of 3-substituted benzoisothiazole 1,1-dioxides with 1,2-diaza-1,3-dienes

• Wenqing Hao,
• Long Wang,
• Jinlei Zhang,
• Dawei Teng and
• Guorui Cao

Beilstein J. Org. Chem. 2024, 20, 280–286, doi:10.3762/bjoc.20.29

• 4aa [35] was isolated in 62% yield (Scheme 4). On the basis of the transformation of 3aa to 4aa, a tentative reaction mechanism is proposed. As shown in Scheme 5, the spiropyridazine-benzosultam 3aa was firstly oxidized to intermediate A. Next, an aziridine was formed with the hydrolysis of the amide

Additive-controlled chemoselective inter-/intramolecular hydroamination via electrochemical PCET process

• Kazuhiro Okamoto,
• Naoki Shida and
• Mahito Atobe

Beilstein J. Org. Chem. 2024, 20, 264–271, doi:10.3762/bjoc.20.27

• presence of methyl vinyl ketone (MVK) as a radical acceptor (Table 1). Tetrabutylammonium dibutyl phosphate (phosphate base), which operates as a PCET initiator through hydrogen bond formation with the N–H bond of amide/carbamate [11], was used as an additive. As a result, N-alkylated product 3 was

• current (Figure 2B, blue line). We considered that the inter- and intramolecular chemoselectivities were derived from the pKa of the proton sources. The pre-organization of the amide substrate and phosphate bases is an important process in PCET [13]. Recently, Gschwind et al. published a detailed NMR

• hydroamination reaction compared to the less acidic PhOH (pKa = 9.95 in H2O) because PhSH supplied free protons (H+) and contributed to the persistence of small aggregates composed of the amide and phosphate base [14]. On the other hand, owing to the insufficient dissociation constant between the proton and

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

• unchanged, although quinoline and its derivatives are easily aminated under the same conditions [17]. No interaction occurred under the conditions of the Chichibabin reaction in an attempt to aminate compound 5 with sodium amide in N,N-dimethylaniline at 140–155 °C for an hour. Thus, quinoquinoline 5

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

• shift was observed, which can be attributed to a weakening of the indigo-type resonance, while the amide resonance remained relatively unaffected (Figure 10). One of the crucial problems accompanying the investigations of photoswitchable molecules are the situations when the photoisomerization product

• the Z-isomer with metal cations. Schematic representation of indigo-type (left) and amide-type (right) resonances in N,N'-acetylindigo (9a). Suggested intermediates for the double bond cleavage for the thermal relaxation of N,N'-diacylindigos: (A) a biradical transient species, (B) a dipolar transient

Metal-catalyzed coupling/carbonylative cyclizations for accessing dibenzodiazepinones: an expedient route to clozapine and other drugs

• Amina Moutayakine and
• Anthony J. Burke

Beilstein J. Org. Chem. 2024, 20, 193–204, doi:10.3762/bjoc.20.19

• occurs first at the amide position. This approach enabled the successful synthesis of a broad spectrum of dibenzodiazepinone units in a one-pot fashion. The synthetic utility of Laha’s approach was highlighted by preparing the corresponding dibenzodiazepinone which was further reacted with N

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

• such as 2d, 2e, and 2f performed well, affording the brominated product 3aa in excellent yields (90–99%). However, transformations of amide 1a to the brominated product 3aa employing unactivated alkyl bromides (2g–i) as reaction partners proceeded with low efficiency (0–53%). Notably, the reactivity of

• aliphatic amide substrates, and proceeds well with activated and unactivated alkyl bromides. Further studies on mechanistic details and the persistent exploration of halogen sources are ongoing in our laboratory. Experimental A 35 mL sealed tube equipped with a stirring bar was charged with 8

Perspectives on push–pull chromophores derived from click-type [2 + 2] cycloaddition–retroelectrocyclization reactions of electron-rich alkynes and electron-deficient alkenes

• Michio Yamada

Beilstein J. Org. Chem. 2024, 20, 125–154, doi:10.3762/bjoc.20.13

• substructures. Consequently, the macrocycle was tethered to the peptide segment through amide–amide hydrogen bonding, and 44 was obtained with 30% yield. The generation of 44 was accompanied by the formation of the corresponding free thread with 62% yield, resulting from the reaction between the thread

Visible-light-induced radical cascade cyclization: a catalyst-free synthetic approach to trifluoromethylated heterocycles

• Chuan Yang,
• Wei Shi,
• Jian Tian,
• Lin Guo,
• Yating Zhao and
• Wujiong Xia

Beilstein J. Org. Chem. 2024, 20, 118–124, doi:10.3762/bjoc.20.12

• amine functionalized substrate, because of competition of the reaction site during the synthesis of substrates. However, an amide-substituted indole furnished a clean product without competition; for example, product 3u was derived from melatonin with an amide functional group, whose reaction to the

Photoinduced in situ generation of DNA-targeting ligands: DNA-binding and DNA-photodamaging properties of benzo[c]quinolizinium ions

• Julika Schlosser,
• Olga Fedorova,
• Yuri Fedorov and
• Heiko Ihmels

Beilstein J. Org. Chem. 2024, 20, 101–117, doi:10.3762/bjoc.20.11

• the amine 2b gave the corresponding amide 2g in 28% yield. The chloro-substituted derivative 2e was synthesized in a Sandmeyer-reaction from 2b in 20% yield. The products 2a–g were identified and fully characterized by NMR spectroscopy (1H, 13C, COSY, HSQC, and HMBC), elemental analyses, and mass

Using the phospha-Michael reaction for making phosphonium phenolate zwitterions

• Matthias R. Steiner,
• Max Schmallegger,
• Larissa Donner,
• Johann A. Hlina,
• Christoph Marschner,
• Judith Baumgartner and
• Christian Slugovc

Beilstein J. Org. Chem. 2024, 20, 41–51, doi:10.3762/bjoc.20.6

• donors attached to the alkyl substituent of the phosphonium center (Figure 3). This hypothesis is further supported by the observation of two very different chemical shifts for the two amide protons in the 1H NMR spectrum of 2b in CDCl3 giving resonance at 5.21 and 8.58 ppm. Kinetic studies In the next

• for the conversion of acrylamide, which is probably disturbed when the hydrogen bond donor solvent methanol is interacting with the amide group and/or the hydroxy group. Conclusion The conjugate addition of 2,4-di-tert-butyl-6-(diphenylphosphino)phenol to Michael acceptor molecules allows for a facile

Synthesis of N-acyl carbazoles, phenoxazines and acridines from cyclic diaryliodonium salts

• Nils Clamor,
• Mattis Damrath,
• Thomas J. Kuczmera,
• Daniel Duvinage and
• Boris J. Nachtsheim

Beilstein J. Org. Chem. 2024, 20, 12–16, doi:10.3762/bjoc.20.2

• equiv amide, 15 mol % CuI, 30 mol % diglyme, 3.00 equiv K2CO3 and 2.00 equiv dibenzo[b,d]iodol-5-ium trifluoromethanesulfonate. Scope of iodanes. aIsolated yields, 200 µmol scale, all reactions carried out in p-xylene, with 1.00 equiv amide 15 mol % CuI, 30 mol % diglyme, 3.00 equiv K2CO3 and 2.00 equiv

Aldiminium and 1,2,3-triazolium dithiocarboxylate zwitterions derived from cyclic (alkyl)(amino) and mesoionic carbenes

• Nedra Touj,
• François Mazars,
• Guillermo Zaragoza and
• Lionel Delaude

Beilstein J. Org. Chem. 2023, 19, 1947–1956, doi:10.3762/bjoc.19.145

• NHC·CS2 zwitterions relies on the deprotonation of an azolium salt with a strong base, typically potassium tert-butoxide or potassium bis(trimethylsilyl)amide (also known as potassium hexamethyldisilazide, KHMDS) followed by the addition of carbon disulfide either in one pot or after the isolation of the

Anion–π catalysis on carbon allotropes

• M. Ángeles Gutiérrez López,
• Mei-Ling Tan,
• Giacomo Renno,
• Augustina Jozeliūnaitė,
• J. Jonathan Nué-Martinez,
• Javier Lopez-Andarias,
• Naomi Sakai and
• Stefan Matile

Beilstein J. Org. Chem. 2023, 19, 1881–1894, doi:10.3762/bjoc.19.140

• derivatives. In fullerene 8, this is an amide with a short ethylene tether for the tertiary amine (Figure 3). Fullerene 8 catalyzed the formation of the addition product 6 with high selectivity over the decarboxylation product 7 [12]. The experimental product ratio A/D8 was divided by the product ratio A/D9

• control 12, a secondary Bingel amide in 13 caused a drop to A/D13/12 = 1.6. Similarly, low A/D14/12 = 1.5 for an ester in 14 supported that removal of the hydrogen-bond donor in 5 rather than steric constraints account for the decrease in anion–π catalysis. Elongation of the tether in the ester series 14

• –16 was as in the amide series from 8 and thus supported entropic contributions to anion–π catalysis. Steric increase of the secondary amide in 17 impeded anion–π catalysis, presumably because the catalytic π surface next to the ammonium cation became inaccessible for anions paired with the tethered

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

• corresponding acyl chloride 11 with thionyl chloride. Finally, the cinchona squaramide with linker 7 and the octadecylated gallic acid chloride 11 were coupled to form an amide using triethylamine as a base. The crude product was purified by chromatography and precipitated from acetonitrile to gain the

Synthetic approach to 2-alkyl-4-quinolones and 2-alkyl-4-quinolone-3-carboxamides based on common β-keto amide precursors

• Yordanka Mollova-Sapundzhieva,
• Plamen Angelov,
• Danail Georgiev and
• Pavel Yanev

Beilstein J. Org. Chem. 2023, 19, 1804–1810, doi:10.3762/bjoc.19.132

• intermediate β-enamino amides 2 are easily available by condensation of the corresponding β-keto amide 1 and an amine (Scheme 1, conditions i). As the amine here plays only an auxiliary role, for the purpose of this research we opted for inexpensive ethylamine. Compounds 2 were obtained by simply stirring a

• dichloromethane solution of the corresponding keto amide 1 with a slight excess of 70% aqueous ethylamine over Na2SO4 and were used directly in the next step, without purification. These compounds are highly reactive at their α-position towards acylating reagents and this provides an opportunity to prepare the

Effects of the aldehyde-derived ring substituent on the properties of two new bioinspired trimethoxybenzoylhydrazones: methyl vs nitro groups

• Dayanne Martins,
• Roberta Lamosa,
• Talis Uelisson da Silva,
• Carolina B. P. Ligiero,
• Sérgio de Paula Machado,
• Daphne S. Cukierman and
• Nicolás A. Rey

Beilstein J. Org. Chem. 2023, 19, 1713–1727, doi:10.3762/bjoc.19.125

• around the conjugated amide single bond (N–C=O). N-Acylhydrazones have also gained attention in literature due to other applications, ranging from medicine to supramolecular chemistry [7][8]. Among their applicability is the area of optoelectronic devices, in which they are used for the manufacture of

• only one NH signal around 12 ppm, indicating the presence exclusively of the (E)-isomer in solution. Furthermore, steric hindrance in these cases allow only for the formation of the antiperiplanar conformation around the conjugated amide single bond. Full assignments, with the chemical shifts and

Synthesis and biological evaluation of Argemone mexicana-inspired antimicrobials

• Jessica Villegas,
• Bryce C. Ball,
• Katelyn M. Shouse,
• Caleb W. VanArragon,
• Ashley N. Wasserman,
• Hannah E. Bhakta,
• Allen G. Oliver,
• Danielle A. Orozco-Nunnelly and
• Jeffrey M. Pruet

Beilstein J. Org. Chem. 2023, 19, 1511–1524, doi:10.3762/bjoc.19.108

• through the use of additional NaOH and refluxing the crude alkylation mixture. After heating for 3 h, the desired intermediates were recovered in acceptable yields over this two-step one-pot sequence. The amide hydrolysis of 7 and 8 to the desired free naphthylamines 9 and 10 proved challenging, but was

• nevertheless successful, albeit in low yields after an extended reaction time. We explored KOH and NH3 as alternatives to NaOH for this amide cleavage, and found the resulting yields less satisfactory. We also explored the amide hydrolysis under acidic conditions as well, though this resulted to almost

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

• with N-(arylthio)phthalimide 14 and N-chlorophthalimide (96) under phase-transfer conditions was developed by Maruoka and co-workers (Scheme 39) [74]. The presence of chiral bifunctional catalysts C and D with the amide, or sulfonamide moieties could improve the enantioselectivity. Also, the

• oxychalcogenation of o‑vinylanilides with N‑(arylthio/arylseleno)succinimides. Lewis base/Brønsted acid dual-catalytic C–H sulfenylation of aryls. Lewis base-catalyzed sulfenoamidation of alkenes. Cyclization of allylic amide using a Brønsted acid and tetrabutylammonium chloride. Catalytic electrophilic

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

• –Cu(I) complexes 12 (Scheme 5). A variety of bases, namely metal alkoxides, alkali metal carbonates, n-butyllithium, and lithium bis(trimethylsilyl)amide have been employed for this purpose. In 2010, Diez-González et al. synthesized a variety of NHC–Cu(I) complexes 14 from imidazolium salts 13 using

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

• converted into several multivalent compounds B by amine or amide bond formations [44][45][46][47]. The transformation of the corresponding azidopyrans and azidooxepanes C or E into multivalent 1,2,3-triazole derivatives D and F by Meldal–Sharpless cycloadditions with suitable alkynes proceeded generally in

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

• ] but to the best of our knowledge, R. Berchtold reported in 1982 the first synthesis in large quantities with a control of the chirality at the sn-2 position (Figure 21) [116]. The synthesis starts from (S)-1,2-isopropylideneglycerol (21.1). The deprotonation of the primary alcohol with sodium amide

Organic thermally activated delayed fluorescence material with strained benzoguanidine donor

• Alexander C. Brannan,
• Elvie F. P. Beaumont,
• Nguyen Le Phuoc,
• George F. S. Whitehead,
• Mikko Linnolahti and
• Alexander S. Romanov

Beilstein J. Org. Chem. 2023, 19, 1289–1298, doi:10.3762/bjoc.19.95

•  1. Benzoguanidine has an extended π-conjugation compared with carbazole and is more nitrogen-rich (three N-atoms vs one in carbazole). Thompson et al. recently reported a series of carbene–metal–amide (CMA) (metal = Cu, Ag, Au) emitters employing a benzoguanidine ligand [10]. The extended π

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

• . (Scheme 34) [99]. The CDC reaction was initiated by a radical oxidative addition of C(sp2)–H and the final product was obtained by amide hydrolysis. The strategy provides a simple and practical method for synthesizing β-oxoketones. In 2015, Cai et al. reported a novel CDC of C(sp3)–H and C(sp2)–H bonds in