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

• ) by using an organocatalyst was reported by Wang and co-workers (Scheme 35) [67]. Several orgnocatalysts, such as piperidine, and pyrrolidine derivatives were evaluated for the coupling reaction, in which pyrrolidine trifluoromethanesulfonamide A was selected as the best catalyst for this purpose. It

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

• -promoted three-component reaction of ammonium acetate, isatins and in situ-generated 3-isatyl-1,4-dicarbonyl compounds. The piperidine-promoted three-component reaction of ammonium acetate, isatins and the in situ-generated dimedone adducts of 3-ethoxycarbonylmethyleneoxindoles afforded mutlifunctionalized

• nitrostyrenes with previously prepared oxindole-functionalized dihydrobenzofuranones (reaction 2 in Scheme 1) [52]. We reported a piperidine-promoted domino reaction of thiophenols and two molecules of 3-phenacylideneoxindoles to give multifunctionalized dispirocyclopentanebisoxindoles (reaction 3 in Scheme 1

• Scheme 1) [12]. In the presence of piperidine, the reaction in methanol at room temperature did not yield the product (Table 1, entry 1). However, the reaction in methanol at elevated temperature gave the expected spiro compound 3a in 51% and 48% yields, respectively (Table 1, entries 2 and 3). The

Enabling artificial photosynthesis systems with molecular recycling: A review of photo- and electrochemical methods for regenerating organic sacrificial electron donors

• Grace A. Lowe

Beilstein J. Org. Chem. 2023, 19, 1198–1215, doi:10.3762/bjoc.19.88

Photoredox catalysis harvesting multiple photon or electrochemical energies

• Mattia Lepori,
• Simon Schmid and
• Joshua P. Barham

Beilstein J. Org. Chem. 2023, 19, 1055–1145, doi:10.3762/bjoc.19.81

Facile access to 3-sulfonylquinolines via Knoevenagel condensation/aza-Wittig reaction cascade involving ortho-azidobenzaldehydes and β-ketosulfonamides and sulfones

• Ksenia Malkova,
• Andrey Bubyrev,
• Stanislav Kalinin and
• Dmitry Dar’in

Beilstein J. Org. Chem. 2023, 19, 800–807, doi:10.3762/bjoc.19.60

• of the target compound 5a estimated by NMR (Table 1, entry 1). Different organic bases were tested, with piperidine performing most efficiently (Table 1, entry 4). Next it was found out that using o-azidobenzaldehyde (1a), PPh3, and an excess of piperidine in relation to ketosulfonamide 2a resulted

CuAAC-inspired synthesis of 1,2,3-triazole-bridged porphyrin conjugates: an overview

• Dileep Kumar Singh

Beilstein J. Org. Chem. 2023, 19, 349–379, doi:10.3762/bjoc.19.29

• (56) in piperidine as shown in Scheme 10. To prepare these conjugates, a porphyrin with a pentafluorophenyl ring (because of its strong electron-withdrawing ability) was chosen and used in the synthesis of azidoporphyrin 51 by replacing the para-fluoro atom with an azide group. Interestingly, the

Synthesis, α-mannosidase inhibition studies and molecular modeling of 1,4-imino-ᴅ-lyxitols and their C-5-altered N-arylalkyl derivatives

• Martin Kalník,
• Sergej Šesták,
• Juraj Kóňa,
• Maroš Bella and
• Monika Poláková

Beilstein J. Org. Chem. 2023, 19, 282–293, doi:10.3762/bjoc.19.24

• hydroxyethylene part of the piperidine ring of swainsonine. This indicates that the (R)-1-hydroxyethyl group of 29 could mimic the interactions of the hydroxypiperidinyl moiety of swainsonine in the active site of dGMII. To evaluate the inhibitory effect of the (R)-1-hydroxyethyl substituent of 29 and other

Identification and determination of the absolute configuration of amorph-4-en-10β-ol, a cadinol-type sesquiterpene from the scent glands of the African reed frog Hyperolius cinnamomeoventris

• Angelique Ladwig,
• Markus Kroll and
• Stefan Schulz

Beilstein J. Org. Chem. 2023, 19, 167–175, doi:10.3762/bjoc.19.16

• by Taber and Gunn [13], using a Diels–Alder reaction as the key step, as it would allow access to several cadinol diastereomers, in line with a diversity-oriented synthetic plan. The synthesis began with enamine formation of isovaleraldehyde (1) and piperidine (2) to give enamine 3 that was reacted

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

• alcohol 66 can be lithitated and reacted with a range of electrophiles, even without the need for a Lewis acid catalyst, and good levels of stereoinduction can be achieved. The method was used for the synthesis of a range of hexose sugars, as well as iminosugars (viz 66 → 67 → 68), wherein the piperidine

Combining the best of both worlds: radical-based divergent total synthesis

• Kyriaki Gennaiou,
• Antonios Kelesidis,
• Maria Kourgiantaki and
• Alexandros L. Zografos

Beilstein J. Org. Chem. 2023, 19, 1–26, doi:10.3762/bjoc.19.1

• ], psychotropic activity, and antiplasmodic activity [64]. Their structural diversity, consisting of different connectivities between piperidine and decalin domains, is especially difficult to be divergently accessed. Shenvi’s group recognized that an aromatic congener within this class could be traced back to

Synthesis of (−)-halichonic acid and (−)-halichonic acid B

• Keith P. Reber and
• Emma L. Niner

Beilstein J. Org. Chem. 2022, 18, 1629–1635, doi:10.3762/bjoc.18.174

• aminobisabolene sesquiterpenoid halichonic acid ((+)-1) from the sponge Halichondra sp. (Figure 1) [4]. This amino acid natural product features a rigid 3-azabicyclo[3.3.1]nonane ring system containing four stereogenic centers within the piperidine ring. In 2021, the same group re-isolated (+)-1 from the sponge

• Axinyssa sp. along with the structurally related compound halichonic acid B ((+)-2) [5]. Structurally, (+)-2 is a pipecolic acid derivative containing a cyclohexenyl ring as a substituent group. This compound also features four stereogenic centers (three of which are located within the piperidine ring) and

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

• synthesized the necessary building blocks, we turned our attention to construct resin-bound peptide 5 (Scheme 4). The assembly of this hexapeptide started with the loading of Fmoc-ᴅ-Trp(Boc)-OH (6) onto 2-chlorotrityl resin with iPr2NEt, which was followed by piperidine treatment to liberate resin-bound amine

• 29. Then, five rounds of DIC/Oxyma-mediated amidation [22] and Nα-deprotection with piperidine led to resin-bound peptide 5. Treatment of 5 with TFA/CH2Cl2 1:99 released 30 into the solution without unmasking the acid-labile protecting groups of the side chains. Subsequently, peptide 30 was cyclized

Vicinal ketoesters – key intermediates in the total synthesis of natural products

• Marc Paul Beller and
• Ulrich Koert

Beilstein J. Org. Chem. 2022, 18, 1236–1248, doi:10.3762/bjoc.18.129

• ]. The major trans-isomer 73 was further converted to the natural products corynoxine and rychnophylline. The minor cis-isomer 74 was used in an intramolecular Tsuji–Trost reaction, where the ketoester served as a nucleophile, which build up the piperidine ring and selectively set the desired cis

Cholyl 1,3,4-oxadiazole hybrid compounds: design, synthesis and antimicrobial assessment

• Anas J. Rasras,
• Mohamed El-Naggar,
• Nesreen A. Safwat and
• Raed A. Al-Qawasmeh

Beilstein J. Org. Chem. 2022, 18, 631–638, doi:10.3762/bjoc.18.63

• were obtained from piperidine and pyrrolidine, respectively, as secondary cyclic amine component (Figure 2). The structures of the newly synthesized compounds were confirmed on the basis of their spectral data in particular nuclear magnetic resonance (NMR) and mass spectrometry (MS) techniques. The 1H

Heteroleptic metallosupramolecular aggregates/complexation for supramolecular catalysis

• Prodip Howlader and
• Michael Schmittel

Beilstein J. Org. Chem. 2022, 18, 597–630, doi:10.3762/bjoc.18.62

Synthesis of piperidine and pyrrolidine derivatives by electroreductive cyclization of imine with terminal dihaloalkanes in a flow microreactor

• Yuki Naito,
• Naoki Shida and
• Mahito Atobe

Beilstein J. Org. Chem. 2022, 18, 350–359, doi:10.3762/bjoc.18.39

• Yuki Naito Naoki Shida Mahito Atobe Graduate School of Science and Engineering, Yokohama National University, Yokohama, Kanagawa 240-8501, Japan 10.3762/bjoc.18.39 Abstract We have successfully synthesized piperidine and pyrrolidine derivatives by electroreductive cyclization using readily

• . Furthermore, piperidine and pyrrolidine derivatives could be obtained on preparative scale by continuous electrolysis for approximately 1 hour. Keywords: electrochemical synthesis; electrocyclization; flow microreactor; heterocyclic amines; imine; Introduction Heterocycles are a very important class of

• compounds and make up more than half of all known organic chemicals [1]. Among them, heterocyclic amines, particularly pyrrolidine and piperidine derivatives, have attracted considerable attention because these are important structural motifs in a wide variety of applications including pharmaceuticals

Regioselective synthesis of methyl 5-(N-Boc-cycloaminyl)-1,2-oxazole-4-carboxylates as new amino acid-like building blocks

• Jolita Bruzgulienė,
• Greta Račkauskienė,
• Aurimas Bieliauskas,
• Vaida Milišiūnaitė,
• Miglė Dagilienė,
• Gita Matulevičiūtė,
• Vytas Martynaitis,
• Sonata Krikštolaitytė,
• Frank A. Sløk and
• Algirdas Šačkus

Beilstein J. Org. Chem. 2022, 18, 102–109, doi:10.3762/bjoc.18.11

• blocks was developed. Regioisomeric methyl 5-(N-Boc-cycloaminyl)-1,2-oxazole-4-carboxylates were prepared by the reaction of β-enamino ketoesters (including azetidine, pyrrolidine or piperidine enamines) with hydroxylamine hydrochloride. Unambiguous structural assignments were based on chiral HPLC

• characteristic signals of the 1,2-oxazole ring skeleton carbons at δ 108.3 (C-4), 150.2 (C-3), and 179.5 (C-5) ppm. The 15N NMR spectrum of 4h exhibited characteristic resonances of nitrogen atoms at δ −294.6 (piperidine) and δ −3.1 (1,2-oxazole) ppm, respectively. Next, we studied the reaction of compounds 4b

Recent advances and perspectives in ruthenium-catalyzed cyanation reactions

• Thaipparambil Aneeja,
• Cheriya Mukkolakkal Abdulla Afsina,
• Padinjare Veetil Saranya and
• Gopinathan Anilkumar

Beilstein J. Org. Chem. 2022, 18, 37–52, doi:10.3762/bjoc.18.4

• such as piperidine, tetrahydroisoquinoline derivatives, and pyrrolidine were also tolerated well in this reaction. The use of the non-toxic and inexpensive acetone cyanohydrin makes this method more advantageous compared to the known methods. 2 Cyanation of arenes and heteroarenes 2.1 Cyanation of

First total synthesis of hoshinoamide A

• Haipin Zhou,
• Zihan Rui,
• Yiming Yang,
• Shengtao Xu,
• Yutian Shao and
• Long Liu

Beilstein J. Org. Chem. 2021, 17, 2924–2931, doi:10.3762/bjoc.17.201

• -OH (4 equiv), HATU/coupling reagent (4 equiv) and DIPEA (8 equiv) in DMF (20 mL). The coupling mixture was filtered and the resin was washed with CH2Cl2 (10 mL × 5) and CH3OH (10 mL × 5). General procedures for deprotection of Fmoc: The loaded resin was treated with a solution of 20 vol % piperidine

• MeOH (3 × 20 mL) and DCM (3 × 20 mL). The unreacted resin was capped with MeOH in a mixture of MeOH/DIPEA/DCM (1:2:7, 10 mL) for 3 h. The resin-bound peptide was added to a mixture of 20% piperidine in DMF (20 mL), and the mixture was shaken for 30 minutes. Then the mixture was filtered, and the resin

• mL) and DCM (3 × 20 mL) to afford the resin-bound dipeptide. The resin-bound dipeptide was added to a mixture of 20% piperidine in DMF (20 mL), and the mixture was shaken for 30 minutes. Then the mixture was filtered, and the resin was washed with MeOH (3 × 20 mL) and DCM (3 × 20 mL). Fmoc-Val-OH

Silica gel and microwave-promoted synthesis of dihydropyrrolizines and tetrahydroindolizines from enaminones

• Robin Klintworth,
• Garreth L. Morgans,
• Stefania M. Scalzullo,
• Charles B. de Koning,
• Willem A. L. van Otterlo and
• Joseph P. Michael

Beilstein J. Org. Chem. 2021, 17, 2543–2552, doi:10.3762/bjoc.17.170

• with the microwave-assisted synthesis of 2,3-dihydro-1H-pyrrolizines from pyrrolidine-based enaminones suggested that the technique might also be suitable for preparing 5,6,7,8-tetrahydroindolizine analogues from the corresponding piperidine systems. In a preliminary investigation we prepared three

• tetrahydroindolizine formation from the piperidine-containing enaminone, we speculated that a simple polar protic solvent might be sufficiently “acidic” for the necessary E/Z equilibration and cyclization of 25a, even though this solvent was unsuitable for the cyclization of the pyrrolidine enaminones (cf. Table 1

Copper-catalyzed monoselective C–H amination of ferrocenes with alkylamines

• Zhen-Sheng Jia,
• Qiang Yue,
• Ya Li,
• Xue-Tao Xu,
• Kun Zhang and
• Bing-Feng Shi

Beilstein J. Org. Chem. 2021, 17, 2488–2495, doi:10.3762/bjoc.17.165

• ][58]. We then explored the scope of multifarious amines. As displayed in Scheme 3, a range of cyclic amines, such as morpholine 4a,b, piperazine 4c, piperidine 4d–j and thiomorpholine 4l,m, reacted smoothly to give the amination products in 23% to 85% yields. A variety of synthetically useful

Advances in mercury(II)-salt-mediated cyclization reactions of unsaturated bonds

• Sumana Mandal,
• Raju D. Chaudhari and
• Goutam Biswas

Beilstein J. Org. Chem. 2021, 17, 2348–2376, doi:10.3762/bjoc.17.153

• piperidine derivatives were also synthesized by Hg(II)-salt-induced cyclization. N-Isopropyl-1-aminohex-4-ene (23) on treatment with 1 equiv HgCl2 followed by reduction with NaBH4 yielded pyrrolidine 24 and piperidine derivative 25 in the ratio of 7:3 [50]. N-Methylaniline derivative 26 undergoes cyclization

• . Synthesis of β-ᴅ-arabinose derivative 18. Hg(OAc)2-mediated synthesis of tetrahydrofuran derivatives. Synthesis of Hg(TFA)2-mediated bicyclic nucleoside derivative. Synthesis of pyrrolidine and piperidine derivatives. HgCl2-mediated synthesis of diastereomeric pyrrolidine derivatives. HgCl2-mediated

Progress and challenges in the synthesis of sequence controlled polysaccharides

• Giulio Fittolani,
• Theodore Tyrikos-Ergas,
• Denisa Vargová,
• Manishkumar A. Chaube and
• Martina Delbianco

Beilstein J. Org. Chem. 2021, 17, 1981–2025, doi:10.3762/bjoc.17.129

Asymmetric organocatalyzed synthesis of coumarin derivatives

• Natália M. Moreira,
• Lorena S. R. Martelli and
• Arlene G. Corrêa

Beilstein J. Org. Chem. 2021, 17, 1952–1980, doi:10.3762/bjoc.17.128

• hydroquinolinone, chromene, piperidine, peptide, lipid, and glycoside moieties (Scheme 2). Bojanowski and co-workers developed a methodology to synthetize 3,4-dihydrocoumarins 10 through a decarboxylative and dearomatizative cascade reaction [33]. This reaction was carried out using coumarin-3-carboxylic acids 8

Development of N-F fluorinating agents and their fluorinations: Historical perspective

• Teruo Umemoto,
• Yuhao Yang and
• Gerald B. Hammond

Beilstein J. Org. Chem. 2021, 17, 1752–1813, doi:10.3762/bjoc.17.123

• fluorination of pyridine or 2-fluoropyridine in anhydrous hydrogen fluoride [17][18] (Scheme 2). Not surprisingly, 1-1 did not become a popular reagent. In 1967, Banks et al. reported reactions of 1-1 with piperidine and triphenylphosphine, -arsine, and -stibine (Scheme 3, entries 1 and 2) [19]. The former