Cryptophycin unit B analogues

• Thomas Schachtsiek,
• Jona Voss,
• Maren Hamsen,
• Beate Neumann,
• Hans-Georg Stammler and
• Norbert Sewald

Beilstein J. Org. Chem. 2025, 21, 526–532, doi:10.3762/bjoc.21.40

• -hydroxy-7-azabenzotriazole; HATU = 1-[bis(dimethylamino)methyliumyl]-1H-1,2,3-triazolo[4,5-b]pyridinium 3-oxide hexafluorophosphate. Three-step diol–epoxide transformation starting from diols 24 and 25. a) (MeO)3CH, pyridinium p-toluenesulfonate, CH2Cl2, rt, 3 h; b) AcBr, CH2Cl2, rt, 3–4 h; c) K2CO3

First series of N-alkylamino peptoid homooligomers: solution phase synthesis and conformational investigation

• Maxime Pypec,
• Laurent Jouffret,
• Claude Taillefumier and
• Olivier Roy

Beilstein J. Org. Chem. 2022, 18, 845–854, doi:10.3762/bjoc.18.85

• 1c, respectively (Scheme 2). The N-Fmoc-protected acid partner 1c was readily prepared from 1a under standard conditions. After a few unsuccessful attempts of coupling using the azabenzotriazole-based coupling reagent HATU [42] or via the formation of an acid chloride with thionyl chloride, we turned

Novel library synthesis of 3,4-disubstituted pyridin-2(1H)-ones via cleavage of pyridine-2-oxy-7-azabenzotriazole ethers under ionic hydrogenation conditions at room temperature

• Romain Pierre,
• Anne Brethon,
• Sylvain A. Jacques,
• Aurélie Blond,
• Sandrine Chambon,
• Sandrine Talano,
• Catherine Raffin,
• Branislav Musicki,
• Claire Bouix-Peter,
• Loic Tomas,
• Gilles Ouvry,
• Rémy Morgentin,
• Laurent F. Hennequin and
• Craig S. Harris

Beilstein J. Org. Chem. 2021, 17, 156–165, doi:10.3762/bjoc.17.16

• -azabenzotriazole; hinge-binder; ionic hydrogenation; library; pyridine-2(1H)-one; Introduction During a recent medicinal chemistry program targeting a kinase to treat skin disorders, we identified the 4-amino-3-carboxamide disubstituted pyridine-2(1H)-one motif (1) as an interesting starting point. Recently, both

• -azabenzotriazole ring to the 7-azabenzotriazoline ring 18 and cleavage of the N–O bond through delocalization of the lone pair at N-2 to liberate 1 and 1H-[1,2,3]triazolo[4,5-b]pyridine as the byproduct. The second pathway occurs through 4 key steps: a) activation of the pyridine in the acidic media; b) ring

Progress in the total synthesis of inthomycins

• Bidyut Kumar Senapati

Beilstein J. Org. Chem. 2021, 17, 58–82, doi:10.3762/bjoc.17.7

• . Finally, hydrolysis of the ester (+)-11 followed by hexafluorophosphate azabenzotriazole tetramethyl uranium (HATU)-mediated coupling with ammonia gave inthomycin C ((+)-3) in 33% yield, containing inseparable tetramethylurea as byproduct (ca. 20%). In 2010, Senapati, Ryu et al. [50] described the first

Synthesis and conformational preferences of short analogues of antifreeze glycopeptides (AFGP)

• Małgorzata Urbańczyk,
• Michał Jewgiński,
• Joanna Krzciuk-Gula,
• Jerzy Góra,
• Rafał Latajka and
• Norbert Sewald

Beilstein J. Org. Chem. 2019, 15, 1581–1591, doi:10.3762/bjoc.15.162

• -diazabicyclo[5.4.0]undec-7-ene (DBU) in NMP, which were shaken with the resin for 2 hours, and the reaction was repeated. Modified PS-Sieber resin was loaded manually with Fmoc-ʟ-Ala-OH or Fmoc-ᴅ-Ala-OH (4 equiv), 1-hydroxy-7-azabenzotriazole (HOAt, 4 equiv), O-(7-azabenzotriazol-1-yl)-N,N,N’,N

Position-dependent impact of hexafluoroleucine and trifluoroisoleucine on protease digestion

• Susanne Huhmann,
• Anne-Katrin Stegemann,
• Kristin Folmert,
• Damian Klemczak,
• Johann Moschner,
• Michelle Kube and
• Beate Koksch

Beilstein J. Org. Chem. 2017, 13, 2869–2882, doi:10.3762/bjoc.13.279

• for 1 h each. The fluorinated amino acids and coupling reagents 1-hydroxy-7-azabenzotriazole (HOAt)/DIC were used in 1.2-fold excess, and the coupling was carried out manually one time overnight. In the case of an insufficient coupling, the coupling was repeated for 3 h with 0.5 equivalents. Prior to

Mycothiol synthesis by an anomerization reaction through endocyclic cleavage

• Shino Manabe and
• Yukishige Ito

Beilstein J. Org. Chem. 2016, 12, 328–333, doi:10.3762/bjoc.12.35

• during column chromatography (CHCl3/MeOH/AcOH), and azabenzotriazole from HATU was difficult to remove. Instead, ethyl (hydroxyimino)cyanoacetate (COMU) [34] coupling gave product 9 in 80% yield after reversed-phase column chromatography purification (H2O/MeOH). Finally, Boc removal and subsequent acetyl

(2R,1'S,2'R)- and (2S,1'S,2'R)-3-[2-Mono(di,tri)fluoromethylcyclopropyl]alanines and their incorporation into hormaomycin analogues

• Armin de Meijere,
• Sergei I. Kozhushkov,
• Dmitrii S. Yufit,
• Christian Grosse,
• Marcel Kaiser and
• Vitaly A. Raev

Beilstein J. Org. Chem. 2014, 10, 2844–2857, doi:10.3762/bjoc.10.302

• = 4-dimethylaminopyridine, EDC = N'-(3-dimethylaminopropyl)-N-ethylcarbodiimide hydrochloride, HATU = O-(7-azabenzotriazole-1-yl)-N,N,N',N'-tetramethyluronium hexafluorophosphate, HOAt = 7-aza-1-hydroxybenzotriazole, MeZ = (4-methylbenzyl)oxycarbonyl, Z = benzyloxycarbonyl. Synthesis of hormaomycin

• °C, 1 h; v) HATU, DIEA, 2,4,6-collidine, CH2Cl2, 20 °C, 4 h; vi) MgBr2·Et2O, EtSH, CH2Cl2, 20 °C, 3.5 h. DIEA = N,N-diisopropylethylamine, HATU = O-(7-azabenzotriazole-1-yl)-N,N,N',N'-tetramethyluronium hexafluorophosphate, HOAt = 7-aza-1-hydroxybenzotriazole, MeZ = (4-methylbenzyl)oxycarbonyl, MOM

Facile synthesis of 1-alkoxy-1H-benzo- and 7-azabenzotriazoles from peptide coupling agents, mechanistic studies, and synthetic applications

• Mahesh K. Lakshman,
• Manish K. Singh,
• Mukesh Kumar,
• Raghu Ram Chamala,
• Vijayender R. Yedulla,
• Domenick Wagner,
• Evan Leung,
• Lijia Yang,
• Asha Matin and
• Sadia Ahmad

Beilstein J. Org. Chem. 2014, 10, 1919–1932, doi:10.3762/bjoc.10.200

• ][1,2,3]triazole, via in situ formation of pyrrolidine enamines and Pd catalysis. Keywords: alkoxy; azabenzotriazole; benzotriazole; peptide-coupling; phosphonium; Introduction Benzotriazole derivatives are of importance in diverse contexts. As examples, in medicinal chemistry substituted benzotriazoles

• purified material to those reported [35] for 1-methoxy-1H-4-azabenzotriazole (1-methoxy-1H-[1,2,3]triazolo[4,5-b]pyridine) and 1-methoxy-1H-7-azabenzotriazole (3-methoxy-3H-[1,2,3]triazolo[4,5-b]pyridine) did not allow for ready identification. A NOE experiment did not result in observable interactions of

• the OMe resonance with the aromatic system. Because neither experiment allowed for unambiguous discrimination between the two structures, 1-methoxy-1H-7-azabenzotriazole was prepared via a known procedure [35]. The chemical shifts for the aromatic protons in the authentic 1-methoxy-1H-7

Synthesis of the first examples of iminosugar clusters based on cyclopeptoid cores

• Mathieu L. Lepage,
• Alessandra Meli,
• Anne Bodlenner,
• Céline Tarnus,
• Francesco De Riccardis,
• Irene Izzo and
• Philippe Compain

Beilstein J. Org. Chem. 2014, 10, 1406–1412, doi:10.3762/bjoc.10.144

• (11 equiv). * Residual solvent peak for CDCl3. • and X are assigned to protons a or b. Monovalent models 11 and 7-valent DNJ derivatives 12. Sub-monomer approach for the synthesis of cyclopeptoids 2–4: DIPEA = N,N-diisopropylethylamine; DIC = N,N’-diisopropylcarbodiimide; HATU O-(7-azabenzotriazole-1

Automated solid-phase peptide synthesis to obtain therapeutic peptides

• Veronika Mäde,
• Sylvia Els-Heindl and
• Annette G. Beck-Sickinger

Beilstein J. Org. Chem. 2014, 10, 1197–1212, doi:10.3762/bjoc.10.118

• carbodiimides (DCC, DIC), classical auxiliary nucleophiles (HOBt, HOAt (1-hydroxy-7-azabenzotriazole) [56]) to uronium reagents (HATU (N-[(dimethylamino)-1H-1,2,3-triazolo-[4,5-b]pyridin-1-ylmethylene]-N-methylmethanaminium hexafluorophosphate N-oxide) [56], TBTU (N-[(1H-benzotriazol-1-yl)(dimethylamino

Stereoselective synthesis of four possible isomers of streptopyrrolidine

• Debendra K. Mohapatra,
• Barla Thirupathi,
• Pragna P. Das and
• Jhillu S. Yadav

Beilstein J. Org. Chem. 2011, 7, 34–39, doi:10.3762/bjoc.7.6

• lactamization of 8a, almost similar yields were obtained for 8b), afforded (4R,5R)-streptopyrrolidine (1) and (4S,5R)-streptopyrrolidine (2) in good to excellent overall yield (Scheme 3). From all of the conditions investigated, Zr(OtBu)4 in presence of 1-hydroxy-7-azabenzotriazole (HOAt) gave the best result

Synthesis of glycosylated β³-homo-threonine conjugates for mucin-like glycopeptide antigen analogues

• Florian Karch and
• Anja Hoffmann-Röder

Beilstein J. Org. Chem. 2010, 6, No. 47, doi:10.3762/bjoc.6.47

• ′,N′-tetramethyluronium hexafluorophosphate, HOBt = N-hydroxybenzotriazole, DIPEA = diisopropylethylamine, HATU = O-(7-azabenzotriazole-1-yl)-N,N,N′,N′-tetramethyluronium hexafluorophosphate, HOAt = N-hydroxy-7-azabenzotriazole, NMM = N-methylmorpholine, TIS = triisopropylsilane. Supporting