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

• .). The protein was eluted using a stepwise gradient of imidazole in lysis buffer (20–500 mM imidazole). The buffer was replaced with lysis buffer using an Amicon Ultra centrifugal filter with a suitable molecular mass cutoff (Merck Millipore). Recombinant AvaA1 and AvaA3 obtained in our previous study

Long oligodeoxynucleotides: chemical synthesis, isolation via catching-by-polymerization, verification via sequencing, and gene expression demonstration

• Yipeng Yin,
• Reed Arneson,
• Alexander Apostle,
• Adikari M. D. N. Eriyagama,
• Komal Chillar,
• Emma Burke,
• Martina Jahfetson,
• Yinan Yuan and
• Shiyue Fang

Beilstein J. Org. Chem. 2023, 19, 1957–1965, doi:10.3762/bjoc.19.146

• results further confirmed that ODN damage by radicals during CBP purification is unlikely. Another concern for long ODN synthesis is the perceived low quantity of product [29]. For example, for a 400 nt ODN synthesis, if the average stepwise yield is 99.0% as usually observed in trityl assay for the

• ) indicated that it contained about 40 ng (0.14 pmol) ODN, which corresponds to a total yield of about 1% for the entire process of ODN synthesis, deprotection and cleavage, CBP purification, and other steps. The result is consistent with a stepwise yield of about 98.9% for ODN synthesis. According to trityl

• assay, the stepwise yield was 99.7%. This indicates that some ODNs were lost during CBP purification and other steps, which is reasonable. It is remarkable that we were successful in using only 1/1600 of the total ODNs we synthesized and purified by CBP (theoretically 1.5625 pmol) for PCR amplification

Decarboxylative 1,3-dipolar cycloaddition of amino acids for the synthesis of heterocyclic compounds

• Xiaofeng Zhang,
• Xiaoming Ma and
• Wei Zhang

Beilstein J. Org. Chem. 2023, 19, 1677–1693, doi:10.3762/bjoc.19.123

• -type AMYs in multicomponent, one-pot, and stepwise reactions for the synthesis of diverse heterocycles related to some bioactive compounds and natural products. Keywords: [3 + 2] cycloaddition; decarboxylation; 1,3-dipolar; double cycloaddition; one-pot synthesis; multicomponent reaction; semi

• aldehydes and alkenes. The first cycloaddition products 3c or 3d can also be used as intermediates for other transformations to synthesize novel heterocyclic rings via multicomponent, one-pot, and stepwise synthesis [63][64]. Presented in the following sections is our work on the development of amino acid

• -based decarboxylative [3 + 2] cycloadditions of N–H-type AMYs B3 and B4 for double cycloadditions. The stereochemistry of the cycloadditions and the combination of the cycloaddition with other transformations to be one-pot or stepwise reactions are also presented. Perspective One-step synthesis of

Sulfur-containing spiroketals from Breynia disticha and evaluations of their anti-inflammatory effect

• Ken-ichi Nakashima,
• Naohito Abe,
• Masayoshi Oyama,
• Hiroko Murata and
• Makoto Inoue

Beilstein J. Org. Chem. 2023, 19, 1604–1614, doi:10.3762/bjoc.19.117

• were concentrated in vacuo to yield the ethyl acetate fraction (11.8 g) and n-butanol fraction (7.4 g), respectively. The ethyl acetate fraction was separated by silica gel CC with CHCl3/MeOH (stepwise gradient of 100:1, 50:1, 30:1, 20:1, 15:1, 10:1, 8:1, and 0:1, v/v) as the eluent. The fractions were

• fractions were pooled by TLC analysis to yield four combined fractions (Frs. B1–B4). Fr. B2 was further separated on an ODS column eluted with MeOH/H2O (stepwise gradient of 2:3, 1:1, 3:2, and 1:0, v/v) to yield four combined subfractions. The second subfraction was separated by silica gel CC with ethyl

Secondary metabolites of Diaporthe cameroonensis, isolated from the Cameroonian medicinal plant Trema guineensis

• Bel Youssouf G. Mountessou,
• Élodie Gisèle M. Anoumedem,
• Blondelle M. Kemkuignou,
• Yasmina Marin-Felix,
• Frank Surup,
• Marc Stadler and
• Simeon F. Kouam

Beilstein J. Org. Chem. 2023, 19, 1555–1561, doi:10.3762/bjoc.19.112

• of this extract was subjected to a silica gel (230–400 mesh) column chromatography using a stepwise gradient of CH2Cl2/MeOH (ranging from 0 to 100% of MeOH, v/v), to afford a total of 8 main series (A–H) obtained on the basis of TLC analyses. However, series A (2.5 g) obtained with pure CH2Cl2 and

• : deionized water (H2O) + 0.1% formic acid (FA) and solvent B: acetonitrile (ACN) + 0.1% formic acid. The binary gradient was: linear of 5% B for 5 min, automatic stepwise gradient from 5 to 100% B for 5–105 min, followed by 100% B for 10 min wash, and finally by 80% ACN + 20% H2O for 10 min re-equilibration

Unraveling the role of prenyl side-chain interactions in stabilizing the secondary carbocation in the biosynthesis of variexenol B

• Moe Nakano,
• Rintaro Gemma and
• Hajime Sato

Beilstein J. Org. Chem. 2023, 19, 1503–1510, doi:10.3762/bjoc.19.107

• hyperconjugation determines whether the reaction proceeds in a stepwise or concerted manner. The second interesting aspect of the biosynthesis of variexenol B is that the biosynthetic pathway involves an intermediate with an exomethylene group. A terpene with an exomethylene group as a starting material is rare

• interacts with the secondary carbocation at C10, reducing the activation energy of the first step by approximately 4.7 kcal/mol. Moreover, due to the stabilization of the secondary carbocation-like intermediate IM2, the reaction proceeds stepwise rather than concertedly [7]. It was found that the final

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

• synthesis of 1,2,5-trisubstituted 7-azaindoles [34]. Inspired by the coupling–cyclization–alkylation sequence and the stepwise Sonogashira coupling–cyclization–iodination protocol to give valuable 3-iodoindoles by Amjad and Knight [35], we reasoned that the interception by an electrophilic iodination step

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

• intramolecular cyclopropanation of iodonium ylides (left); and, stepwise intermolecular cycloadditions with olefins (right). Concerted cycloaddition pathway for the metal-free, intramolecular cyclopropanation of iodonium ylides. Nucleophilic (top) and electrophilic (bottom) addition pathways proposed by Koser

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

• elimination of nitrous acid, accompanied by aromatization, yielded furan 13. In addition to the stepwise mechanism, a concerted ring-expansion can be also acceptable [25]. Conclusion Although nitrocyclopropanedicarboxylic acid esters 1a have been used in organic syntheses, nitrocyclopropanes possessing an

Construction of hexabenzocoronene-based chiral nanographenes

• Ranran Li,
• Di Wang,
• Shengtao Li and
• Peng An

Beilstein J. Org. Chem. 2023, 19, 736–751, doi:10.3762/bjoc.19.54

• stepwise Scholl reaction from 0 °C to room temperature by removing 84 hydrogens total. NG 128 is composed of seven HBCs and exhibit an extraordinary size, which reaches 3.50 nm in width and 1.25 nm in height. Single crystals X-ray diffraction indicates only one form (M or P) of enantiomer which can be

Synthesis of medium and large phostams, phostones, and phostines

• Jiaxi Xu

Beilstein J. Org. Chem. 2023, 19, 687–699, doi:10.3762/bjoc.19.50

• phostams, phostones, and phostines are summarized. They include cyclizations and annulations. Cyclizations achieve ring construction through the formations of C–C, C–O, P–C, and P–O bonds in the rings, while annulations build the rings via [5 + 2], [6 + 1], and [7 + 1] fashions with the stepwise formation

• , and phostine derivatives through a stepwise bond formation fashion. To date, [5 + 2], [6 + 1], and [7 + 1] annulations have been developed for the synthesis of medium phostams and phostones. 2.1 Synthesis via [5 + 2] annulation A mixture of 2-phenyl/ethoxy-1-phenyl-1,2-dihydro-4H-benzo[d][1,3,2

Nostochopcerol, a new antibacterial monoacylglycerol from the edible cyanobacterium Nostochopsis lobatus

• Naoya Oku,
• Saki Hayashi,
• Yuji Yamaguchi,
• Hiroyuki Takenaka and
• Yasuhiro Igarashi

Beilstein J. Org. Chem. 2023, 19, 133–138, doi:10.3762/bjoc.19.13

• MeOH to adjust its concentration to 60% (v/v). This was extracted with CH2Cl2 for three times, and the CH2Cl2-soluble layer was partitioned between aqueous 90% MeOH and n-hexane. The most active aqueous MeOH layer (113.3 mg) was subjected to ODS flash chromatography with a stepwise elution by MeCN/50

1,4-Dithianes: attractive C2-building blocks for the synthesis of complex molecular architectures

• Bram Ryckaert,
• Ellen Demeyere,
• Frederick Degroote,
• Hilde Janssens and
• Johan M. Winne

Beilstein J. Org. Chem. 2023, 19, 115–132, doi:10.3762/bjoc.19.12

• reported far less commonly than their use in (4 + 3) cycloadditions [94]. Simple hydrocarbon allyl cations can also undergo (3 + 2) cycloadditions through a purely stepwise cation olefin cyclization-type pathway, but these generally give complex mixtures and low yields and show unpredictable substrate

• suppress homodimerization, via a stepwise (3 + 2) cycloaddition of the initially generated cumyl cation across the olefin in amylene. Our group became intrigued by the potential of dihydrodithiins to act as carbocation-stabilizing groups, as these would represent a synthetic equivalent of ‘naked’ allyl

One-pot double annulations to confer diastereoselective spirooxindolepyrrolothiazoles

• Juan Lu,
• Bin Yao,
• Desheng Zhan,
• Zhuo Sun,
• Yun Ji and
• Xiaofeng Zhang

Beilstein J. Org. Chem. 2022, 18, 1607–1616, doi:10.3762/bjoc.18.171

•  2C). Results and Discussion The optimized reaction conditions of stepwise, one-pot and cascade (two-step with one operational step) processes for N,S-acetalation and decarboxylative 1,3-dipolar cycloaddition were developed by using two equivalents of 4-bromobenzaldehyde (1a), ʟ-cysteine (2) and

• purification from N,S-acetalation with 1.0:1.15 of 1a/2 at 25 °C for 6 h with EtOH as solvent, in situ followed by addition of 1.1:1.0 of 1a/4a for [3 + 2] cycloaddition at 90 °C for 9 h gave compound 5a with the 81% of LC yield. Next, the stepwise process was also carried out by using the thioproline 3a (1

• stereocenters and two heterocycles in a diastereoselective fashion, and without intermediate purification. The one-pot four-component synthesis in green metrics analysis is compared with the stepwise reaction process to pinpoint the overwhelming advantages of the one-pot approach in the CE, MP, PMI, and SI by

Comparison of crystal structure and DFT calculations of triferrocenyl trithiophosphite’s conformance

• Ruslan P. Shekurov,
• Mikhail N. Khrizanforov,
• Ilya A. Bezkishko,
• Tatiana P. Gerasimova,
• Almaz A. Zagidullin,
• Daut R. Islamov and
• Vasili A. Miluykov

Beilstein J. Org. Chem. 2022, 18, 1499–1504, doi:10.3762/bjoc.18.157

• describe the London dispersion interactions as implemented in the Gaussian 16 program. Results and Discussion Previous electrochemical studies for triferrocenyl trithiophosphite revealed in their cyclovoltammograms three reversible one-electron peaks corresponding to stepwise oxidation of the three

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

• reaction coordinates (IRCs) were performed at the same level of theory to determine two local minima through transition states in each stepwise [50]. Besides, the rate constant of reaction based on the transitional state theory method and quantum tunneling effect was calculated by the following expression

New azodyrecins identified by a genome mining-directed reactivity-based screening

• Atina Rizkiya Choirunnisa,
• Kuga Arima,
• Yo Abe,
• Noritaka Kagaya,
• Kei Kudo,
• Hikaru Suenaga,
• Junko Hashimoto,
• Manabu Fujie,
• Noriyuki Satoh,
• Kazuo Shin-ya,
• Kenichi Matsuda and
• Toshiyuki Wakimoto

Beilstein J. Org. Chem. 2022, 18, 1017–1025, doi:10.3762/bjoc.18.102

• stepwise HMM-based search using models for “VlmA'' (PF09924: LPG_synthase_C) and the amino acid sequence of VlmH identified 179 pairs of VlmA/VlmH, indicating that approximately 5.7% of the actinobacteria present in the NCBI Refseq database are potential producers of aliphatic azoxy natural products. The

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

• -(alkylamino)glycine units is investigated. We demonstrate that N-(methylamino)glycine homooligomers can be readily synthesized in solution using N-Boc-N-methylhydrazine as a peptoid submonomer and stepwise or segment coupling methodologies. Their structures were analyzed in solution by 1D and 2D NMR, in the

Continuous flow synthesis of azobenzenes via Baeyer–Mills reaction

• Jan H. Griwatz,
• Anne Kunz and
• Hermann A. Wegner

Beilstein J. Org. Chem. 2022, 18, 781–787, doi:10.3762/bjoc.18.78

• the temperature and the residence time were successively changed to achieve the highest conversion to AB. The residence time was increased from 5.0 to 50.0 min and the temperature was raised stepwise from 25 °C up to 90 °C (Figure 1). After the set residence time an aliquot was collected, diluted with

Bioinspired tetraamino-bisthiourea chiral macrocycles in catalyzing decarboxylative Mannich reactions

• Hao Guo,
• Yu-Fei Ao,
• De-Xian Wang and
• Qi-Qiang Wang

Beilstein J. Org. Chem. 2022, 18, 486–496, doi:10.3762/bjoc.18.51

• ][46][47][48][49][50][51][52]. Results and Discussion Synthesis of macrocycles The tetraamino-bisthiourea chiral macrocycles were synthesized by a stepwise strategy (Scheme 1). The easily available chiral diamines including 1,2-cyclohexanediamines and 1,2-diphenylethylenediamines were chosen as the

A Se···O bonding catalysis approach to the synthesis of calix[4]pyrroles

• Qingzhe Tong,
• Zhiguo Zhao and
• Yao Wang

Beilstein J. Org. Chem. 2022, 18, 325–330, doi:10.3762/bjoc.18.36

• , several synthetic methods to access these compounds have been reported [54][55]. The classical approaches to synthesis of calix[4]pyrrole derivatives mainly involved a stepwise synthesis and Lewis acid as well as Brønsted acid catalysis [54][55]. Notably, a noncovalent catalysis approach to accessing

Trichloroacetic acid fueled practical amine purifications

• Aleena Thomas,
• Baptiste Gasch,
• Enzo Olivieri and
• Adrien Quintard

Beilstein J. Org. Chem. 2022, 18, 225–231, doi:10.3762/bjoc.18.26

• Aleena Thomas Baptiste Gasch Enzo Olivieri Adrien Quintard Aix-Marseille Univ, CNRS, Centrale Marseille, iSm2, Marseille, France 10.3762/bjoc.18.26 Abstract Amine purification have for long been dominated by tedious stepwise processes involving the generation of large amounts of undesired waste

Stepwise PEG synthesis featuring deprotection and coupling in one pot

• Logan Mikesell,
• Dhananjani N. A. M. Eriyagama,
• Yipeng Yin,
• Bao-Yuan Lu and
• Shiyue Fang

Beilstein J. Org. Chem. 2021, 17, 2976–2982, doi:10.3762/bjoc.17.207

• Logan Mikesell Dhananjani N. A. M. Eriyagama Yipeng Yin Bao-Yuan Lu Shiyue Fang Department of Chemistry, Michigan Technological University, 1400 Townsend Drive, Houghton, MI 49931, USA ChampionX, 11177 South Stadium Drive, Sugar Land, TX 77478, USA 10.3762/bjoc.17.207 Abstract The stepwise

• one pot. The deprotonation step, and the isolation and purification of the intermediate product after deprotection using existing approaches are no longer needed when the one-pot approach is used. Because the stepwise PEG synthesis usually requires multiple PEG elongation cycles, the new PEG synthesis

• peptides, proteins and nucleic acids and to evade undesired immune responses, monodisperse PEGs are required or highly desired [12][13]. To meet the needs of monodisperse PEGs, significant efforts have been made to develop stepwise methods for their synthesis [14][15][16][17][18][19][20][21][22][23][24][25

Iron-catalyzed domino coupling reactions of π-systems

• Austin Pounder and
• William Tam

Beilstein J. Org. Chem. 2021, 17, 2848–2893, doi:10.3762/bjoc.17.196

• substantial improvements in efficient synthesis because of domino reactions. These protocols are more atom-economic, produce less waste, and demand less time compared to a classical stepwise reaction. Although iron-catalyzed domino reactions require a mindset that differs from the more routine noble-metal

α-Ketol and α-iminol rearrangements in synthetic organic and biosynthetic reactions

• Scott Benz and
• Andrew S. Murkin

Beilstein J. Org. Chem. 2021, 17, 2570–2584, doi:10.3762/bjoc.17.172

• -xylulose-5-phosphate reductoisomerase (DXR), uses a different mechanism to accomplish the carbon-skeleton rearrangement of its substrate 63 [19]; kinetic isotope effect experiments have excluded an α-ketol rearrangement and instead support a stepwise retro-aldol/aldol sequence for formation of intermediate