Pd-catalyzed asymmetric Suzuki–Miyaura coupling reactions for the synthesis of chiral biaryl compounds with a large steric substituent at the 2-position

• Yongsu Li,
• Bendu Pan,
• Xuefeng He,
• Wang Xia,
• Yaqi Zhang,
• Hao Liang,
• Chitreddy V. Subba Reddy,
• Rihui Cao and
• Liqin Qiu

Beilstein J. Org. Chem. 2020, 16, 966–973, doi:10.3762/bjoc.16.85

• hindrance of the 4-substituted boronic acid. Next, in order to confirm our speculation, the amide group of the aryl bromide was replaced with other functional groups, as shown in Scheme 2. When the amide group was changed into an amine, coupling product 5a was obtained quantitatively but without any

Recent developments in photoredox-catalyzed remote ortho and para C–H bond functionalizations

• Rafia Siddiqui and
• Rashid Ali

Beilstein J. Org. Chem. 2020, 16, 248–280, doi:10.3762/bjoc.16.26

• 22 upon coordination with the carbonyl oxygen atom of the amide group. The complex 22 then coordinated to the acrylate product 23, which rearranged to 24, and the β-hydride elimination of 24 yielded the desired olefinated product 21. C–H olefination of phenolic ethers: Based on Ackermann and co

The use of isoxazoline and isoxazole scaffolding in the design of novel thiourea and amide liquid-crystalline compounds

• Itamar L. Gonçalves,
• Rafaela R. da Rosa,
• Vera L. Eifler-Lima and
• Aloir A. Merlo

Beilstein J. Org. Chem. 2020, 16, 175–184, doi:10.3762/bjoc.16.20

• behavior displayed SmA mesophase. A similar liquid crystal behavior can be seen in amides 19 and 21 where the isomers differ only in the relative orientation of the isoxazoline ring to the amide group, while the amide group in 19 can resonate to the nitrogen atom in the isoxazoline ring, 21 does not. All

Microwave-assisted synthesis of 2-substituted 4,5,6,7-tetrahydro-1,3-thiazepines from 4-aminobutanol

• María C. Mollo,
• Natalia B. Kilimciler,
• Juan A. Bisceglia and
• Liliana R. Orelli

Beilstein J. Org. Chem. 2020, 16, 32–38, doi:10.3762/bjoc.16.5

• excess, (LR/substrate 2.5:1, toluene, reflux) the reaction was chemoselective toward the amide group, and compound 2a was obtained in high yield (93%), although the unreacted LR complicated the isolation and purification of the product. Lowering the molar ratio of the starting materials to strictly

Combining the Ugi-azide multicomponent reaction and rhodium(III)-catalyzed annulation for the synthesis of tetrazole-isoquinolone/pyridone hybrids

• Gerardo M. Ojeda,
• Prabhat Ranjan,
• Pavel Fedoseev,
• Lisandra Amable,
• Upendra K. Sharma,
• Daniel G. Rivera and
• Erik V. Van der Eycken

Beilstein J. Org. Chem. 2019, 15, 2447–2457, doi:10.3762/bjoc.15.237

• using a secondary amide as directing group (Scheme 1C) [32][48]. In these protocols, the amide group plays a dual behavior of directing group and reaction center, as it participates in the final ring-closing reductive elimination. Herein, we report the synthesis of a new class of tetrazolo-isoquinolone

• evaluate the effect of the substituent in the phenyl ring. Interestingly, the presence of substituents in the ortho-position of the amide group (acting as a directing group) decreased the yields, with substrates bearing substituents Me, Br and Cl leading to moderate yields of compounds 4b, 4c, and 4d

• , while a OMe substituent in this position no product 4e was obtained. On the other hand, no significant effect was observed when the substituents were placed in the meta- or para-position (4f–m) of the amide group. It must be noted that for substrates bearing a halogen (1k–m) in the meta-position of the

Recent advances in transition-metal-catalyzed incorporation of fluorine-containing groups

• Xiaowei Li,
• Xiaolin Shi,
• Xiangqian Li and
• Dayong Shi

Beilstein J. Org. Chem. 2019, 15, 2213–2270, doi:10.3762/bjoc.15.218

• -selective fluorination of α-bromocarbonyl compounds using a copper/CsF catalyst system (Scheme 32). Tertiary alkyl fluorides could be generated by this fluorination through the assistance of an amide group. From the results, the catalytic cycle of this reaction includes: 1) copper salt induced generation of

• the alkyl radical species B from substrate A and 2) fluorination of the alkyl radical species B with CuF2, which is in situ-generated from the reaction of CuXBr and CsF with the aid of an amide group, gives the desired product and recyclable CuF. Csp2–H bond formation catalyzed by Cu catalysts: In

Azologization and repurposing of a hetero-stilbene-based kinase inhibitor: towards the design of photoswitchable sirtuin inhibitors

• Christoph W. Grathwol,
• Nathalie Wössner,
• Sören Swyter,
• Adam C. Smith,
• Enrico Tapavicza,
• Robert K. Hofstetter,
• Anja Bodtke,
• Manfred Jung and
• Andreas Link

Beilstein J. Org. Chem. 2019, 15, 2170–2183, doi:10.3762/bjoc.15.214

• selective Sirt1 inhibitor, passed phase II clinical trials as a disease-modifying therapeutic for Huntington’s disease (HD) and was acquainted by AOP Orphan Pharmaceuticals AG for phase III trials in 2017 [9][10]. Its structure comprises a carboxamide moiety, which mimics the amide group of the endogenous

Tautomerism as primary signaling mechanism in metal sensing: the case of amide group

• Vera Deneva,
• Georgi Dobrikov,
• Aurelien Crochet,
• Daniela Nedeltcheva,
• Katharina M. Fromm and
• Liudmil Antonov

Beilstein J. Org. Chem. 2019, 15, 1898–1906, doi:10.3762/bjoc.15.185

• , Switzerland 10.3762/bjoc.15.185 Abstract The concept for sensing systems using the tautomerism as elementary signaling process has been further developed by synthesizing a ligand containing 4-(phenyldiazenyl)naphthalene-1-ol as a tautomeric block and an amide group as metal capturing antenna. Although it has

• been expected that the intramolecular hydrogen bonding (between the tautomeric hydroxy group and the nitrogen atom from the amide group) could stabilize the pure enol form in some solvents, the keto tautomer is also observed. This is a result from the formation of intramolecular associates in some

• solvents. Strong bathochromic and hyperchromic effects in the visible spectra accompany the 1:1 formation of complexes with some alkaline earth metal ions. Keywords: amide group; azo dye; molecular sensor; sidearm; tautomerism; Introduction The design of new organic sensing systems is an undividable part

Diaminoterephthalate–α-lipoic acid conjugates with fluorinated residues

• Leon Buschbeck,
• Aleksandra Markovic,
• Gunther Wittstock and
• Jens Christoffers

Beilstein J. Org. Chem. 2019, 15, 981–991, doi:10.3762/bjoc.15.96

• the first title compound 3 in 71% yield. Due to the electron-withdrawing amide group, the chromophore is relatively electron deficient (absorption at 420 nm and emission at 495 nm). In order to achieve a bathochromic shift of absorption and emission bands, the DAT and ALA moieties should be

Syntheses and chemical properties of β-nicotinamide riboside and its analogues and derivatives

• Mikhail V. Makarov and
• Marie E. Migaud

Beilstein J. Org. Chem. 2019, 15, 401–430, doi:10.3762/bjoc.15.36

• glycosylation (Figure 3). This intermediate is subsequently approached by Nam from the less hindered side. Subsequently, Franchetti et al. [30] modified the above TMSOTf-protocol by introducing the preliminary silylation of the amide group of Nam, a procedure based on the chemistry developed by Vorbrüggen [24

Study on the regioselectivity of the N-ethylation reaction of N-benzyl-4-oxo-1,4-dihydroquinoline-3-carboxamide

• Pedro N. Batalha,
• Luana da S. M. Forezi,
• Maria Clara R. Freitas,
• Nathalia M. de C. Tolentino,
• Ednilsom Orestes,
• José Walkimar de M. Carneiro,
• Fernanda da C. S. Boechat and
• Maria Cecília B. V. de Souza

Beilstein J. Org. Chem. 2019, 15, 388–400, doi:10.3762/bjoc.15.35

• regioselective manner, without the formation of any byproduct derived from the N-alkylation of the amide group. Structural characterization Table 1 gives the nuclear magnetic resonance spectroscopic data that allowed to confirm the structures of substances 5 and 7, and thus also confirmed the regioselectivity of

• HMBC spectra. In the COSY spectrum of 7, the correlations between the hydrogen of the amide group (CONH) and of the benzylic hydrogens (CONHCH2Ph) confirm again the occurrence of the alkylation in the nitrogen of the oxoquinoline nucleus (Figure 4). From the HMBC spectrum of 7 it was observed that H-2

• structure that the intramolecular hydrogen bond between the hydrogen of the amide group, CON–H, and the carbonyl oxygen (C-4), promotes coplanarity between the oxoquinoline nucleus and the CONH moiety of this amide group connected to C-3, as expected. An additional crystallographic description and the full

Sigmatropic rearrangements of cyclopropenylcarbinol derivatives. Access to diversely substituted alkylidenecyclopropanes

• Guillaume Ernouf,
• Jean-Louis Brayer,
• Christophe Meyer and
• Janine Cossy

Beilstein J. Org. Chem. 2019, 15, 333–350, doi:10.3762/bjoc.15.29

• -acylamino)cyclopropanes] possessing a single substituent at C2, it is possible to rely either on the steric hindrance or on the coordinating ability of the amide group. Thus, the hydrogenation of trifluoroacetamide 51 catalyzed by Pd/C afforded N-trifluoroacetylaminocyclopropane 55 as the major diastereomer

Synthesis of 3-aminocoumarin-N-benzylpyridinium conjugates with nanomolar inhibitory activity against acetylcholinesterase

• Nisachon Khunnawutmanotham,
• Cherdchai Laongthipparos,
• Patchreenart Saparpakorn,
• Nitirat Chimnoi and
• Supanna Techasakul

Beilstein J. Org. Chem. 2018, 14, 2545–2552, doi:10.3762/bjoc.14.231

• the amide group and dimethoxy substituents on the chromene ring to the amino acid residues Tyr72, Tyr124, Trp286, and Tyr341 in the PAS; and (5) the hydrogen atoms of phenyl ring to Glu202 and a methoxy group to Ser293. Moreover, C–H–π and π–π interactions were found for compound 9h. The C–H–π

• and of the amide group to Phe338 in the CAS and between the nitrogen atom of the amide group to Tyr124 in the PAS were the key interactions of the synthesized 3-aminocoumarin-N-benzylpyridinium conjugates in the binding pocket of AChE. Conclusion A series of 3-amino-6,7-dimethoxycoumarins conjugated

Synthesis of dihydroquinazolines from 2-aminobenzylamine: N³-aryl derivatives with electron-withdrawing groups

• Nadia Gruber,
• Jimena E. Díaz and
• Liliana R. Orelli

Beilstein J. Org. Chem. 2018, 14, 2510–2519, doi:10.3762/bjoc.14.227

• %) to excellent (>80%) overall yields from 2-ABA in three steps (Table 3, last column). Regarding the ring-closure step, Table 3 shows a clear dependence of the reaction times with steric hindrance of the amide group (R) in the substrate, displaying the order R = CH3 < CH2CH3 < CH(CH3)2 << C(CH3)3. In

The mechanochemical synthesis of quinazolin-4(3H)-ones by controlling the reactivity of IBX

• Md Toufique Alam,
• Saikat Maiti and
• Prasenjit Mal

Beilstein J. Org. Chem. 2018, 14, 2396–2403, doi:10.3762/bjoc.14.216

• using several arylamines and hypervalent iodine(V) reagents by direct mixing is unrealistic because of the high exothermic reaction or explosion. Herein we demonstrate, when anilines were substituted with an amide group at the ortho-position, successful chemical reactions could be performed due to

Synthesis and supramolecular self-assembly of glutamic acid-based squaramides

• Juan V. Alegre-Requena,
• Marleen Häring,
• Isaac G. Sonsona,
• Alex Abramov,
• Eugenia Marqués-López,
• Raquel P. Herrera and
• David Díaz Díaz

Beilstein J. Org. Chem. 2018, 14, 2065–2073, doi:10.3762/bjoc.14.180

• properties of supramolecular gels [33]. Specifically, we exchanged the amide group of N-stearoyl-L-glutamic acid (1, Figure 1), a known LMW gelator [34], by its non-classical isostere [35][36] 1,4-disubstituted 1,2,3-triazole 2 (Figure 1). This approach enabled us to fine-tuning the gelation capacity and the

• -L-glutamic acid bearing the squaramide moiety instead of the amide group (4, Figure 1). Interestingly, the gelation properties of the diester precursor 3 (Figure 1) was found to be superior than 4, allowing to obtain a variety of gels at lower concentration than those obtained with 2, as well as to

A hemicryptophane with a triple-stranded helical structure

• Augustin Long,
• Olivier Perraud,
• Erwann Jeanneau,
• Christophe Aronica,
• Jean-Pierre Dutasta and
• Alexandre Martinez

Beilstein J. Org. Chem. 2018, 14, 1885–1889, doi:10.3762/bjoc.14.162

• three imine functions is highly sable [12][13]. Hydrogen bonds between the amide group and the formed imine function could account for the high stability of this intermediate, shifting the equilibrium between the different oligomers and the cage in favor of this latter (vide infra). 1H NMR of cage 1 The

• are twisted into a triple helix with the lone pair of the amines and the amide hydrogen atoms oriented toward the cavity, while the amide oxygen atoms are oriented outwards. Intramolecular hydrogen bonding between the nitrogen of the amine function of one linker with the N–H of the amide group of

Recent applications of chiral calixarenes in asymmetric catalysis

• Mustafa Durmaz,
• Erkan Halay and
• Selahattin Bozkurt

Beilstein J. Org. Chem. 2018, 14, 1389–1412, doi:10.3762/bjoc.14.117

• water. The high catalytic efficieny of this proline-functionalized calix[4]arene organocatalyst was attributed to the presence of the amide group and its synergistic effect through hydrogen-bonding interaction with the substrate. The scope and limitations of the asymmetric aldol reactions between a wide

Oligonucleotide analogues with cationic backbone linkages

• Melissa Meng and
• Christian Ducho

Beilstein J. Org. Chem. 2018, 14, 1293–1308, doi:10.3762/bjoc.14.111

• units are replaced with the NAA-modification. In the NAA-modification, several rotatable bonds are combined with the rigid amide group, and it is therefore expected to represent an example of the aforementioned positively charged backbone linkage with 'intermediate' conformational flexibility (vide

2-Iodo-N-isopropyl-5-methoxybenzamide as a highly reactive and environmentally benign catalyst for alcohol oxidation

• Takayuki Yakura,
• Tomoya Fujiwara,
• Akihiro Yamada and
• Hisanori Nambu

Beilstein J. Org. Chem. 2018, 14, 971–978, doi:10.3762/bjoc.14.82

• of the iodobenzamides depends on the ortho-relationship of the iodine atom to the amide group. Therefore, we then investigated N-isopropyl-2-iodobenzamides that have an additional functional group on the benzene ring. Based on the results of our studies on phenol oxidation [60][62] and Ishihara’s [52

An efficient and facile access to highly functionalized pyrrole derivatives

• Meng Gao,
• Wenting Zhao,
• Hongyi Zhao,
• Ziyun Lin,
• Dongfeng Zhang and
• Haihong Huang

Beilstein J. Org. Chem. 2018, 14, 884–890, doi:10.3762/bjoc.14.75

• reasonable mechanism for the formation of 3,4-diamide groups, besides the amidation of ethyl ester group on the 2-position to give one amide group on the pyrrole ring. Due to the electron-withdrawing effect of the ester group at the 2-position in 12a–k, the carbonyl group at the 3-position of the pyrrole was

Recent advances in synthetic approaches for medicinal chemistry of C-nucleosides

• Kartik Temburnikar and
• Katherine L. Seley-Radtke

Beilstein J. Org. Chem. 2018, 14, 772–785, doi:10.3762/bjoc.14.65

• ) [74]. Protected D-ribonolactone 27 was treated with lithiated pyridine to obtain lactol 28 (Figure 10B). Deoxygenation and reduction gave 29, wherein the isopropylidene group was also removed. Conversion of the cyano to an amide group, followed by removal of the silyl protecting group gave 24, which

Investigations towards the stereoselective organocatalyzed Michael addition of dimethyl malonate to a racemic nitroalkene: possible route to the 4-methylpregabalin core structure

• Denisa Vargová,
• Rastislav Baran and
• Radovan Šebesta

Beilstein J. Org. Chem. 2018, 14, 553–559, doi:10.3762/bjoc.14.42

• nitroalkene is bound to the catalyst via a squaramide moiety including an ancillary C–H···O hydrogen bond [45][46]. The dimethyl malonate anion binds via the protonated tertiary amide group. The calculations suggest that using organocatalyst C7 the preferred enantiomers of the product, within like and unlike

Development of a fluorogenic small substrate for dipeptidyl peptidase-4

• Futa Ogawa,
• Masanori Takeda,
• Kanae Miyanaga,
• Keita Tani,
• Ryuji Yamazawa,
• Kiyoshi Ito,
• Atsushi Tarui,
• Kazuyuki Sato and
• Masaaki Omote

Beilstein J. Org. Chem. 2017, 13, 2690–2697, doi:10.3762/bjoc.13.267

• modification of the amino group to an amide group. The loss of fluorescence is the result of attenuation of the electron-donating effect of the amino group to the benzene ring. In particular, a large difference between the fluorescence emissions of 1 and H-Gly-Pro-1 at around 460 nm was observed. H-Gly-Pro-1

Recent progress in the racemic and enantioselective synthesis of monofluoroalkene-based dipeptide isosteres

• Myriam Drouin and
• Jean-François Paquin

Beilstein J. Org. Chem. 2017, 13, 2637–2658, doi:10.3762/bjoc.13.262

• , which is a promising inhibitor of the non-structural protein NS5A, an interesting target of the chronic hepatitis C virus [52]. The monofluoroalkene replaced the amide group, and the use of a dipeptide isostere containing a proline residue favoured a γ-turn substructure which is necessary for the