Synthesis of new representatives of A₃B-type carboranylporphyrins based on meso-tetra(pentafluorophenyl)porphyrin transformations

• Victoria M. Alpatova,
• Evgeny G. Rys,
• Elena G. Kononova and
• Valentina A. Ol'shevskaya

Beilstein J. Org. Chem. 2024, 20, 767–776, doi:10.3762/bjoc.20.70

• the p-fluorine atom in the pentafluorophenyl substituent with an azide functionality which upon reduction with SnCl2 resulted in the formation of the corresponding porphyrin with an amino group. Pentafluorophenyl-substituted A3B-porphyrins were studied and transformed to thiol and amino-substituted

• the ability of the amino group in porphyrin 5 to enter acylation reactions with 4-(N-maleimido)benzoyl chloride (8, prepared in situ from 4-(N-maleimido)benzoic acid (9) and oxalyl chloride) and chloroacetyl chloride (10) with the aim of using these compounds for further functionalization. The

• molecules which have been also used for selective delivery of the drug to cancer cells [45]. Here, biotin was conjugated to porphyrin 12 which was obtained by alkylation of the amino group in compound 5 with chloroacetyl chloride (10) to give porphyrin biotin conjugate 14 in 76% yield (Scheme 4). We also

New variochelins from soil-isolated Variovorax sp. H002

• Jabal Rahmat Haedar,
• Aya Yoshimura and
• Toshiyuki Wakimoto

Beilstein J. Org. Chem. 2024, 20, 692–700, doi:10.3762/bjoc.20.63

• serine (Ser), a β-hydroxyaspartic acid (Hya), and a unique γ-amino acid biosynthetically originating from an arginine and a methyl malonate (4-amino-7-guanidino-3-hydroxy-2-methylheptanoic acid), with the amino group acylated by a saturated fatty acid. Subsequent HMBC and MS/MS analyses indicated that

Possible bi-stable structures of pyrenebutanoic acid-linked protein molecules adsorbed on graphene: theoretical study

• Yasuhiro Oishi,
• Motoharu Kitatani and
• Koichi Kusakabe

Beilstein J. Org. Chem. 2024, 20, 570–577, doi:10.3762/bjoc.20.49

• PASE on graphene [3][4]. The protein and pyrene are connected via an alkyl chain. The atomic configuration of this alkyl chain is believed not to be largely affected by the substitution of the succinimidyl group with an amino group. On the other hand, proteins alone do not readily form adsorbed

Facile approach to N,O,S-heteropentacycles via condensation of sterically crowded 3H-phenoxazin-3-one with ortho-substituted anilines

• Eugeny Ivakhnenko,
• Vasily Malay,
• Pavel Knyazev,
• Nikita Merezhko,
• Nadezhda Makarova,
• Oleg Demidov,
• Gennady Borodkin,
• Andrey Starikov and
• Vladimir Minkin

Beilstein J. Org. Chem. 2024, 20, 336–345, doi:10.3762/bjoc.20.34

• (31), is formed between the nitro and imino groups of the N-aryl ring. The compounds 4a–h intensely absorb light in the spectral range of 400–550 nm, with maxima at 439–459 nm, ε = 20600–37100 M−1⋅cm−1 (Figure 3 and Table 1). The introduction of an amino group into the p-position of the N-phenyl

• , Supporting Information File 1), 2-(arylamino)-3H-phenoxazin-3-ones 4a–h manifest two reduction waves at Е1/2RED1 = −1.36 ± 1.69 V and Е1/2RED2 = −1.85 ± 2.12 V. Oxidation of 4a–f,h occurs as an irreversible process at Е1/2OX = 0.81–1.07 V. For 4g bearing an amino group, the oxidation potential is shifted to

Optimizations of lipid II synthesis: an essential glycolipid precursor in bacterial cell wall synthesis and a validated antibiotic target

• Milandip Karak,
• Cian R. Cloonan,
• Brad R. Baker,
• Rachel V. K. Cochrane and
• Stephen A. Cochrane

Beilstein J. Org. Chem. 2024, 20, 220–227, doi:10.3762/bjoc.20.22

• , followed by in situ re-acetylation of the C2-amino group and C6-alcohol with acetic anhydride, resulting in the formation of disaccharide 4 in a one-pot fashion. The anomeric benzyl protecting group in disaccharide 4 was then removed via a Pd/C-catalyzed hydrogenation reaction, producing a mixture of α/β

Identification of the p-coumaric acid biosynthetic gene cluster in Kutzneria albida: insights into the diazotization-dependent deamination pathway

• Seiji Kawai,
• Akito Yamada,
• Yohei Katsuyama and
• Yasuo Ohnishi

Beilstein J. Org. Chem. 2024, 20, 1–11, doi:10.3762/bjoc.20.1

• ) then forms a diene moiety using two malonyl units to synthesize 3-aminoavenalumic acid (3-AAA, 7) from 3,4-AHBA-AvaA3. The amino group of 3-AAA is diazotized by AvaA6 using nitrous acid derived from the ANS pathway (AvaE and AvaD) to form 3-diazoavenalumic acid (3-DAA, 8), and this diazo group is

Construction of diazepine-containing spiroindolines via annulation reaction of α-halogenated N-acylhydrazones and isatin-derived MBH carbonates

• Xing Liu,
• Wenjing Shi,
• Jing Sun and
• Chao-Guo Yan

Beilstein J. Org. Chem. 2023, 19, 1923–1932, doi:10.3762/bjoc.19.143

• ylide B. Thirdly, the intermediate C is formed by the nucleophilic substitution of a halide ion in substrate 1 by the allylic ylide B. Then, Michael addition of the amino group to the C=C bond results in the cyclic intermediate D. Finally, the spiro[indoline-3,5'-[1,2]diazepine] 3 is produced by the

Complexes of resorcin[4]arene with secondary amines: synthesis, solvent influence on “in-out” structure, and theoretical calculations of non-covalent interactions

• Waldemar Iwanek

Beilstein J. Org. Chem. 2023, 19, 1525–1536, doi:10.3762/bjoc.19.109

• transferred from the hydroxy group of R[4]A to the amine molecule, forming a hydrogen bond between the proton of the positively charged amino group and the oxygen anion in the R[4]A molecule (ArO−···H+NHR2). For sec-amine molecules such as morpholine and N-methylpiperazine, an “out” complex is formed by

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

• the para-position to the amino group, and when the para-position of aniline was occupied by another group, ortho-substituted products were identified. Fu′s research group established an isothiocyanatoalkylthiation of styrenes 9 in the presence of isothiocyanate 154 and N-(organothio)succinimides 1

α-(Aminomethyl)acrylates as acceptors in radical–polar crossover 1,4-additions of dialkylzincs: insights into enolate formation and trapping

• Angel Palillero-Cisneros,
• Paola G. Gordillo-Guerra,
• Fernando García-Alvarez,
• Olivier Jackowski,
• Franck Ferreira,
• Fabrice Chemla,
• Joel L. Terán and
• Alejandro Perez-Luna

Beilstein J. Org. Chem. 2023, 19, 1443–1451, doi:10.3762/bjoc.19.103

• . Trapping of this enolate would lead to β-amino acid units, a class of compounds that has attracted a great deal of attention [19][20][21][22][23][24]. An obvious possible shortcoming that had to be considered was still that the generated zinc enolate III having a β-amino group could undergo β-elimination

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

• diaminocarbenes) Cu(I) hexamethyldisilazide complexes by using lithium hexamethyldisilazide as a base in 2017 (Scheme 15) [29]. The initially formed NHC–CuCl complexes 41, 44, and 47 reacted with another molecule of LiN(SiMe3)2 to undergo nucleophilic substitution of Cl by a bis(trisilyl)amino group to furnish

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

Selective construction of dispiro[indoline-3,2'-quinoline-3',3''-indoline] and dispiro[indoline-3,2'-pyrrole-3',3''-indoline] via three-component reaction

• Ziying Xiao,
• Fengshun Xu,
• Jing Sun and
• Chao-Guo Yan

Beilstein J. Org. Chem. 2023, 19, 1234–1242, doi:10.3762/bjoc.19.91

• of reactive carbonyl groups in intermediate B2, one carbonyl group is in the benzoyl moiety and another carbonyl group is in the 1,3-cyclohexanedione part. In this case the amino group selectively attacked the benzoyl group to give cyclic intermediate D, while the two carbonyl groups in the 1,3

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

• rigidity in the corresponding transition state (Scheme 23) [53]. In 2023, a chiral phosphoric acid ent-P17-mediated aza-Friedel–Crafts alkylation was reported between 5-aminopyrazole 92 as the π-nucleophile and 3H-indol-3-ones 69 as electrophilic reagents. The presence of an amino group in pyrazole 92 is

Clauson–Kaas pyrrole synthesis using diverse catalysts: a transition from conventional to greener approach

• Dileep Kumar Singh and
• Rajesh Kumar

Beilstein J. Org. Chem. 2023, 19, 928–955, doi:10.3762/bjoc.19.71

• interaction between DES and the amino group enhance the nucleophlicity of the amines. (3) Microwave-assisted reactions Microwave-assisted heating offers a number of advantages over conventional heating, such as greater precision, excellent product yields, and very rapid reaction. This section describes the

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

• , intermediate 13 was transformed to (±)-6,7-secoagroclavine in enantiopure form, as reported previously by the Bisai group in 2018 [115]. All the spectroscopic data of 13 were in agreement with those reported in the literature, confirming that the radical addition reaction provided the trans amino group due to

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

• , but a dihydrofuran, so the cyclopropane 1b’ reported in the literature [12][13][19] is presumably incorrect [22]. In the cases of donor–acceptor cyclopropanes possessing an electron-donating group such as an alkoxy or amino group, ring expansion caused by an intramolecular attack of nitro oxygen

Eschenmoser coupling reactions starting from primary thioamides. When do they work and when not?

• Lukáš Marek,
• Jiří Váňa,
• Jan Svoboda and
• Jiří Hanusek

Beilstein J. Org. Chem. 2023, 19, 808–819, doi:10.3762/bjoc.19.61

• nitrogen and carbonyl oxygen, generating both nucleophilic and electrophilic centers, i.e., a free amino group and protonated carbonyl group, which is much more prone to nucleophilic attack than a carbonyl group itself. Quantum calculations (see the left side of Figure 2) show that the relative stabilities

Access to cyclopropanes with geminal trifluoromethyl and difluoromethylphosphonate groups

• Ita Hajdin,
• Romana Pajkert,
• Mira Keßler,
• Jianlin Han,
• Haibo Mei and
• Gerd-Volker Röschenthaler

Beilstein J. Org. Chem. 2023, 19, 541–549, doi:10.3762/bjoc.19.39

• amino group to the copper centre of an intermediately produced metallocarbene, thus favouring the formation of one diastereoisomer of 7g [50]. In addition, the cyclopropanes 7a–g were always obtained as mixtures of two diastereoisomers in different ratios and all attempts to separate them using column

Dipeptide analogues of fluorinated aminophosphonic acid sodium salts as moderate competitive inhibitors of cathepsin C

• Karolina Wątroba,
• Małgorzata Pawełczak and
• Marcin Kaźmierczak

Beilstein J. Org. Chem. 2023, 19, 434–439, doi:10.3762/bjoc.19.33

• Poznań, Uniwersytetu Poznańskiego 10, 61-614 Poznań, Poland 10.3762/bjoc.19.33 Abstract In this paper, we present the solvolysis reaction of dipeptide analogues of fluorinated aminophosphonates with simultaneous quantitative deprotection of the amino group. To the best of our knowledge, this work is the

• as potential inhibitors of cathepsins. The phosphorus atom by default should mimic the tetrahedral intermediate, but this role may also be played by the hydroxy group present in hydroxyphosphonates, which mimic the carbonyl carbon in the peptide bond by forming a hydrogen bond with the amino group of

• fluorinated aminophosphonates [23][24] with the simultaneous deprotection of the amino group. The free amines were subjected to kinetic studies to investigate their interaction with cathepsin C. The required steps should be simple and fast, and the conditions of the reactions should be as mild as possible

Solid-phase total synthesis and structural confirmation of antimicrobial longicatenamide A

• Takumi Matsumoto,
• Takefumi Kuranaga,
• Yuto Taniguchi,
• Weicheng Wang and
• Hideaki Kakeya

Beilstein J. Org. Chem. 2022, 18, 1560–1566, doi:10.3762/bjoc.18.166

• ] and provides insights into the biosynthesis pathways of these peptides [14]. However, the biosynthetic gene clusters of compounds 1–4 remain unidentified. Therefore, the least sterically hindered amine, namely the amino group of glycine, was selected as a nucleophile of the cyclization reaction in

• )-protected ᴅ-serine 12 (Scheme 2). Treatment of the olefin 15 with trifluoroacetic acid (TFA) cleaved the Boc protecting group and the acetonide to deliver unsaturated amino alcohol 16. The amino group in 16 was protected by the fluorenylmethyloxycarbonyl (Fmoc) protecting group for solid-phase peptide

1,4,6,10-Tetraazaadamantanes (TAADs) with N-amino groups: synthesis and formation of boron chelates and host–guest complexes

• Artem N. Semakin,
• Ivan S. Golovanov,
• Yulia V. Nelyubina and
• Alexey Yu. Sukhorukov

Beilstein J. Org. Chem. 2022, 18, 1424–1434, doi:10.3762/bjoc.18.148

• bearing a free amino group (Scheme 4). However, this product was prone to a ring–chain isomerization forming an equilibrating mixture of azaadamantane 15, tris-imine 16, and bicycle 17 in solution as determined by NMR data (see Supporting Information File 1 for details). We were able to shift the

• equatorial group appear to be somewhat elongated (by ca. 0.02–0.03 Å) compared to other C–N bonds of the triazinane ring. In the 1N,2O-TAADs the amino group is always axial, while OH groups occupy either eq,eq (in 21 and 21·HCl) or ax,eq (in 8a) positions (Figure 2d and f). A similar isomerism is observed in

Ferrocenoyl-adenines: substituent effects on regioselective acylation

• Mateja Toma,
• Gabrijel Zubčić,
• Jasmina Lapić,
• Senka Djaković,
• Davor Šakić and
• Valerije Vrček

Beilstein J. Org. Chem. 2022, 18, 1270–1277, doi:10.3762/bjoc.18.133

• at the exocyclic amino group of adenine affect the reactivity of the respective purine anion and govern the regioselectivity of the ferocenoylation reaction (N7- versus N9-product). By using an appropriate substituent at the C6 position in the purine ring, one can tune the isomeric product ratio, i.e

• N7- and N9-isomers are usually obtained. In some cases, the acylation of adenine may also occur at the exo-amino group (N6) [30][31]. In general, the literature on the regioselectivity of alkylation of adenines/purines is more abundant, includes an array of reaction conditions (base, solvent

• in the alkylation of purines were reported earlier [40]. Now, we demonstrate for the first time that similar effect is operative in the acylation of purines. It is evident from the results in Table 1 that the N9/N7 ratio increases with the increasing size of the substituent at the exocyclic amino

A one-pot electrochemical synthesis of 2-aminothiazoles from active methylene ketones and thioureas mediated by NH₄I

• Shang-Feng Yang,
• Pei Li,
• Zi-Lin Fang,
• Sen Liang,
• Hong-Yu Tian,
• Bao-Guo Sun,
• Kun Xu and
• Cheng-Chu Zeng

Beilstein J. Org. Chem. 2022, 18, 1249–1255, doi:10.3762/bjoc.18.130

• can act as a bi-functional organocatalyst due to the existence of both Lewis base (NH2) and Brønsted acidic (COOH) sites. In the suggested mechanism, the carboxy group may polarize the carbonyl group of the active methylene ketone and the amino group as a Lewis base serves the formation of enolate to

Experimental and theoretical studies on the synthesis of 1,4,5-trisubstituted pyrrolidine-2,3-diones

• Nguyen Tran Nguyen,
• Vo Viet Dai,
• Nguyen Ngoc Tri,
• Luc Van Meervelt,
• Nguyen Tien Trung and
• Wim Dehaen

Beilstein J. Org. Chem. 2022, 18, 1140–1153, doi:10.3762/bjoc.18.118

• broad peak corresponding to the proton of the secondary amino group (NH) at a chemical shift of 11.74 ppm. The intramolecular hydrogen bond led to the appearance of a resonance signal of the amino group at high chemical shift. Also, the coupling between the amino proton and methylene protons was