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

• conjugates (99a–d, 103a,b) were utilized for the preparation of porphyrin-fullerene dyads 100a–d and 104a,b in 30–70% yield by the reaction with C60 and sarcosine in toluene under microwave conditions. The photophysical and computational studies of these ZnP-Tri-C60 conjugates revealed that the 1,2,3

Chemical synthesis of tripeptide thioesters for the biotechnological incorporation into the myxobacterial secondary metabolite argyrin via mutasynthesis

• David C. B. Siebert,
• Roman Sommer,
• Domen Pogorevc,
• Michael Hoffmann,
• Silke C. Wenzel,
• Rolf Müller and
• Alexander Titz

Beilstein J. Org. Chem. 2019, 15, 2922–2929, doi:10.3762/bjoc.15.286

• sarcosine (Sar) and derivatives. Chemical synthesis of the native sequence ᴅ-Ala-Dha-Sar thioester required revision of the sequential peptide synthesis into a convergent strategy where the thioester with sarcosine was formed before coupling to the Dha-containing dipeptide. Keywords: antibiotic; argyrin

• possibility resides in the dehydroalanine-sarcosine motif and modification seems possible as deduced from the crystal structure [11] of argyrin with elongation factor G1. Despite the successful implementation of total syntheses of argyrin derivatives, a more rapid access towards diversity in the argyrins and

• relatively small structural changes to probe the biosynthetic machinery: the native sequence ᴅ-alanine-dehydroalanine-sarcosine was varied in a small library by replacing dehydroalanine (Dha) with ᴅ- or ʟ-alanine and sarcosine with glycine (Figure 3). The synthesis of these biosynthesis analogs 9–14 was

Fluorinated maleimide-substituted porphyrins and chlorins: synthesis and characterization

• Valentina A. Ol’shevskaya,
• Elena G. Kononova and
• Andrei V. Zaitsev

Beilstein J. Org. Chem. 2019, 15, 2704–2709, doi:10.3762/bjoc.15.263

• ylide, generated in situ from sarcosine and paraformaldehyde. The reaction of chlorin 9 with the excess of NaN3 in DMF/DMSO resulted in tetraazide chlorin 10 in 85% yield after the purification. The reduction of azide groups in chlorin 10 with SnCl2 in MeOH gave tetraamino-substituted chlorin 11 which

The enzymes of microbial nicotine metabolism

• Paul F. Fitzpatrick

Beilstein J. Org. Chem. 2018, 14, 2295–2307, doi:10.3762/bjoc.14.204

• succinate semialdehyde and methylamine, mao. The expression of both proteins is regulated by nicotine [38][39], suggesting that both contribute in vivo. Mabo (γ-N-methylaminobutyrate demethylating oxidase) is similar in sequence to sarcosine dehydrogenase, and characterization of purified Mabo showed that

• it contains covalently-bound FAD and produces hydrogen peroxide as a product in addition to 4-aminobutryate [5][38]. Mabo also catalyzes the oxidative demethylation of sarcosine. Based on these results, the mechanism of the enzyme is similar to that of sarcosine oxidase, direct oxidation of the C–N

Multicomponent synthesis of spiropyrrolidine analogues derived from vinylindole/indazole by a 1,3-dipolar cycloaddition reaction

• Manjunatha Narayanarao,
• Lokesh Koodlur,
• Vijayakumar G. Revanasiddappa,
• Subramanya Gopal and
• Susmita Kamila

Beilstein J. Org. Chem. 2016, 12, 2893–2897, doi:10.3762/bjoc.12.288

• stereospecific cyclic adducts. Keywords: L-proline; ninhydrin; sarcosine; spiropyrrolidine; 5-vinylindazole; 5-vinylindole; Introduction The [3 + 2] cycloaddition between azomethine ylides and olefins/acetylene as dipolarophiles is an important reaction to access a number of novel heterocyclic spiro scaffolds

• in the construction of functionalized spiro compounds. We report herein the facile synthesis of novel spiropyrrolidine compounds through a one-pot three-component reaction involving N-substituted vinylindole/indazole, ninhydrin and sarcosine/L-proline. The present multicomponent reaction (MCR) leads

• out by reacting N-alkylvinyl products 3 with azomethine ylide, generated in situ through decarboxylative condensation of ninhydrin (4) and sarcosine (5). The 1,3-dipolar cycloaddition of the ylide with the olefin 3 yielded spiropyrrolidines 7 with regiospecificity (Table 1, entries 1–4). The formation

An effective one-pot access to polynuclear dispiroheterocyclic structures comprising pyrrolidinyloxindole and imidazothiazolotriazine moieties via a 1,3-dipolar cycloaddition strategy

• Alexei N. Izmest’ev,
• Galina A. Gazieva,
• Natalya V. Sigay,
• Sergei A. Serkov,
• Valentina A. Karnoukhova,
• Vadim V. Kachala,
• Alexander S. Shashkov,
• Igor E. Zanin,
• Angelina N. Kravchenko and
• Nina N. Makhova

Beilstein J. Org. Chem. 2016, 12, 2240–2249, doi:10.3762/bjoc.12.216

• -triazine moieties has been developed. The method relies on a 1,3-dipolar cycloaddition of azomethine ylides generated in situ from isatin derivatives and sarcosine to 6-benzylideneimidazo[4,5-e]thiazolo[3,2-b]-1,2,4-triazine-2,7-diones. Keywords: azomethine ylides; cycloaddition; diastereoselectivity

• combined the imidazothiazolotriazine and 3,3’-spiropyrrolidinyloxindole moieties by a 1,3-dipolar cycloaddition of an azomethine ylide generated in situ from paraformaldehyde and sarcosine to oxoindolylidene derivatives of imidazothiazolotriazine. During this work we have found that the “small” azomethine

• ylide generated from paraformaldehyde and sarcosine approaches the double bond plane in (oxoindolylidene)imidazothiazolotriazines mainly from the side of the imidazolidine ring opposite to the phenyl groups (syn attack) (Scheme 1) [5]. To further expand the spectrum of biological activity, it is of

The regioselective synthesis of spirooxindolo pyrrolidines and pyrrolizidines via three-component reactions of acrylamides and aroylacrylic acids with isatins and α-amino acids

• Tatyana L. Pavlovskaya,
• Fedor G. Yaremenko,
• Victoria V. Lipson,
• Svetlana V. Shishkina,
• Oleg V. Shishkin,
• Vladimir I. Musatov and
• Alexander S. Karpenko

Beilstein J. Org. Chem. 2014, 10, 117–126, doi:10.3762/bjoc.10.8

• azomethine ylides, generated in situ via decarboxylative condensation of isatins and N-substituted α-amino acids (sarcosine, proline and thiazolidine-4-carboxilic acid) in a three-component fashion. Results and Discussion The three-component condensation of equimolar amounts of isatins 1, α-amino acids 2 and

• acrylamides 3 in boiling aqueous methanol (1:3) afforded the spirooxindoles 4a–4g in moderate to excellent yields (Table 1). The reaction times largely depend on the reactivity of the employed α-amino acid. The longest reaction time (7 h) was found for sarcosine, while the fastest reaction (40 min) was found

• dipolarophiles 5 with non-stabilized azomethine ylides generated from isatins 1 and sarcosine/proline has led to spiropyrrolidines 6a,6b and spiropyrrolizidines 6c–6h in moderate to good yields. In this reaction also two regioisomers can be expected, but in all experiments solely the regioisomer 6 is isolated

The chemistry of isoindole natural products

• Klaus Speck and
• Thomas Magauer

Beilstein J. Org. Chem. 2013, 9, 2048–2078, doi:10.3762/bjoc.9.243

• extensive NMR studies and unambiguously confirmed by a four-step synthesis. In 1991, a more concise and elegant route to this antimicrobial metabolite was established by Schubert-Zsilavecz [11]. The reaction was initiated by heating paraformaldehyde (13) and sarcosine (14) in the presence of benzoquinone 16