Photochromic derivatives of indigo: historical overview of development, challenges and applications

• Gökhan Kaplan,
• Zeynel Seferoğlu and
• Daria V. Berdnikova

Beilstein J. Org. Chem. 2024, 20, 228–242, doi:10.3762/bjoc.20.23

• ]. After the determination of the molecular structure of indigo in 1883, various precursors such as isatin (1), cinnamic acid (2), 2-nitrobenzaldehyde (3), aniline (4), 2-aminobenzoic acid (5), phenylglycine (6), 1-(1H-indol-1-yl)ethan-1-one (7) and indole (8) have been used in the synthesis (Figure 1) [4

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

• , serine, and norvaline to give products 11a–f in 53–88% yields with greater than 8.5 dr (Scheme 7). The reactions with leucine and phenylglycine (R2 = iPr and Ph) as amino acids gave mainly mono-cycloaddition products and very little double cycloaddition products 11g and 11h due to the steric hindrance of

• -aminoisobutyric acid, phenylglycine and valine with Ph or iPr groups could also be used for the synthesis of the monocycloaddition products for the post-condensation reactions. It is worth noting that in the one-pot synthesis involving an intramolecular click reaction, no Cu catalyst was used. A similar reaction

Palladium-catalyzed enantioselective three-component synthesis of α-arylglycine derivatives from glyoxylic acid, sulfonamides and aryltrifluoroborates

• Bastian Jakob,
• Nico Schneider,
• Luca Gengenbach and
• Georg Manolikakes

Beilstein J. Org. Chem. 2023, 19, 719–726, doi:10.3762/bjoc.19.52

• afforded the Pbf-protected [23] phenylglycine derivative 10a in high yield and enantioselectivity, an almost racemic mixture of 10b was obtained from the corresponding (p-methoxyphenyl)boronic acid (2b, Scheme 2a). This decrease in enantioselectivity can be attributed to a faster racemic background

Unsaturated fatty acids and a prenylated tryptophan derivative from a rare actinomycete of the genus Couchioplanes

• Shun Saito,
• Kanji Indo,
• Naoya Oku,
• Hisayuki Komaki,
• Masashi Kawasaki and
• Yasuhiro Igarashi

Beilstein J. Org. Chem. 2021, 17, 2939–2949, doi:10.3762/bjoc.17.203

• -7 to C-1' and from H-1' to C-6. The absolute configuration was determined by chiral anisotropy analysis after derivatization with each of the phenylglycine methyl ester (PGME) enantiomers [27], which gave positive ΔδH(S-R) values for NH-1, H-2, H-4, H-5 and H-8 and negative values for H-9, NH-11 and

Synthesis of new substituted 7,12-dihydro-6,12-methanodibenzo[c,f]azocine-5-carboxylic acids containing a tetracyclic tetrahydroisoquinoline core structure

• Agnieszka Grajewska,
• Maria Chrzanowska and
• Wiktoria Adamska

Beilstein J. Org. Chem. 2021, 17, 2511–2519, doi:10.3762/bjoc.17.168

• , several acids have been prepared in satisfactory yields. An unprecedented chemical behavior of a Petasis reaction product in diluted HCl solution leading to the formation of a phenylglycine derivative has been observed and the mechanism explaining such reactivity has been proposed. Keywords: amino acids

• phenylglycine derivative 8 as the sole product with 87% yield (Scheme 7). When we decreased the concentration of HCl to 2% in the reaction with 6a, the substrate was isolated unchanged even after prolonged reaction time. In light of these results, we investigated the chemical behavior of compound 12, the

• studies. The unusual interesting behavior of Petasis reaction product 6a in diluted HCl solution leading to phenylglycine derivative 8 has been detected and the mechanism explaining this reactivity has been proposed. Natural isopavine alkaloids and synthetic derivatives of isopavine. The structure and

Towards new NIR dyes for free radical photopolymerization processes

• Haifaa Mokbel,
• Guillaume Noirbent,
• Didier Gigmes,
• Frédéric Dumur and
• Jacques Lalevée

Beilstein J. Org. Chem. 2021, 17, 2067–2076, doi:10.3762/bjoc.17.133

• and the tertiary aromatic amines 3-(dimethylamino)benzyl alcohol (DABA) and N-phenylglycine (NPG), respectively, for the polymerization of a benchmark monomer (PETIA, Scheme 2). The polymerization profiles were recorded by real-time Fourier transform infrared spectroscopy (FTIR, the procedure is

Three new O-isocrotonyl-3-hydroxybutyric acid congeners produced by a sea anemone-derived marine bacterium of the genus Vibrio

• Dandan Li,
• Enjuro Harunari,
• Tao Zhou,
• Naoya Oku and
• Yasuhiro Igarashi

Beilstein J. Org. Chem. 2020, 16, 1869–1874, doi:10.3762/bjoc.16.154

• , respectively (Figure 1). A database search identified the planar structure of 4 in a patent that described 5 (Figure 1) from marine obligate Vibrio sp. C-984 [9]. To determine the absolute configuration of C3 in 1–4, an anisotropy-based chiral analysis using a chiral derivatization reagent, phenylglycine

• mg; tR 9.8 min). Preparation of the (S)- and (R)-phenylglycine methyl ester amides To a solution of 4 (1.7 mg, 10 μmol) in anhydrous CH2Cl2 (0.5 mL) in a dried vial were added (S)-phenylglycine methyl ester (PGME, 3.3 mg, 16.4 μmol), DMAP (1.2 mg, 10 μM), and DIC (3.0 μL, 19.5 μmol), and the mixture

A cyclopeptide and three oligomycin-class polyketides produced by an underexplored actinomycete of the genus Pseudosporangium

• Shun Saito,
• Kota Atsumi,
• Tao Zhou,
• Keisuke Fukaya,
• Daisuke Urabe,
• Naoya Oku,
• Md. Rokon Ul Karim,
• Hisayuki Komaki and
• Yasuhiro Igarashi

Beilstein J. Org. Chem. 2020, 16, 1100–1110, doi:10.3762/bjoc.16.97

• absolute configuration of the Trp residue was determined using a chiral derivatizing reagent, phenylglycine methyl ester (PGME) [21]. Compound 1 was reacted with both enantiomers of PGME to give (R)- and (S)-PGME amides 5a and 5b, and the difference of the 1H NMR chemical shifts ΔδS−R was calculated around

• a solution of 1 (1.0 mg, 2.0 μmol) in dry DMF (100 μL) and N,N-diisopropylethylamine (10 μL) were added (R)-phenylglycine methyl ester [(R)-PGME, 1.6 mg, 7.9 μmol], PyBOP (3.8 mg, 7.3 μmol), and HOBt (1.0 mg, 7.4 μmol) at room temperature. After stirring for 3 h, ice-water was added to the reaction

Recent advances in photocatalyzed reactions using well-defined copper(I) complexes

• Mingbing Zhong,
• Xavier Pannecoucke,
• Philippe Jubault and
• Thomas Poisson

Beilstein J. Org. Chem. 2020, 16, 451–481, doi:10.3762/bjoc.16.42

• -phenylglycine ester, and the alkylated products were obtained in good to excellent yields. In addition, various glycine derivatives were also alkylated in good yields. Finally, the authors demonstrated the synthetic interest of their methodology through the alkylation of di- and tripeptides. The authors studied

Synthesis of nonracemic hydroxyglutamic acids

• Dorota G. Piotrowska,
• Iwona E. Głowacka,
• Andrzej E. Wróblewski and
• Liwia Lubowiecka

Beilstein J. Org. Chem. 2019, 15, 236–255, doi:10.3762/bjoc.15.22

• employing the same methodology. From N-Boc-D-phenylglycinal Since the phenyl group has been applied for many occasions as a precursor of the carboxylic function selection of D-phenylglycine as a starting material in the synthesis of the N-Boc-protected (2S,3R)-2 makes a useful addition to the existing

• ; c) t-BuMe2SiCl, TEA, DMAP, CH2Cl2; d) AcOH, CH2Cl2; e) H2, 10% Pd(OH)2, Boc2O, MeOH; f) KOH, EtOH; g) NaIO4, RuCl3, CCl4/MeCN/H2O; h) MeI, KHCO3, DMF. Synthesis of N-Boc-protected (2S,3R)-2 from D-phenylglycine. Reagents and conditions: a) BnMgCl, ether; b) Me2C(OMe)2, PPTS, toluene; c) NaIO4, RuCl3

Green synthesis of new chiral 1-(arylamino)imidazo[2,1-a]isoindole-2,5-diones from the corresponding α-amino acid arylhydrazides in aqueous medium

• Nadia Bouzayani,
• Jamil Kraїem,
• Sylvain Marque,
• Yakdhane Kacem,
• Abel Carlin-Sinclair,
• Jérôme Marrot and
• Béchir Ben Hassine

Beilstein J. Org. Chem. 2018, 14, 2923–2930, doi:10.3762/bjoc.14.271

• (Scheme 2, Table 1) in a sealed tube in the presence of Et3N and under solvent-free conditions. From green chemistry point of view, this enhanced procedure appears to be a good alternative of the precedents for the synthesis of hydrazides 3a–m [26][27][28][29]. Moreover, the phenylglycine phenylhydrazide

• (3d), (L)-cysteine phenylhydrazide (3g), (L)-tyrosine phenylhydrazide (3j), (L)-alanine 4-chlorophenylhydrazide (3k), (L)-phenylglycine 4-chlorophenylhydrazide (3l) and (L)-phenylalanine 4-chlorophenylhydrazide (3m) were synthesized for the first time in this work. Verardo et al. [29] have shown that

Defining the hydrophobic interactions that drive competence stimulating peptide (CSP)-ComD binding in Streptococcus pneumoniae

• Bimal Koirala,
• Robert A. Hillman,
• Erin K. Tiwold,
• Michael A. Bertucci and
• Yftah Tal-Gan

Beilstein J. Org. Chem. 2018, 14, 1769–1777, doi:10.3762/bjoc.14.151

• and 13). Aliphatic hydrophobic side-chains, namely Leu or Ile, were replaced with proteogenic and non-proteogenic aliphatic residues (Ile, Leu, Val, norleucine (Nle), or norvaline (Nva)), while aromatic hydrophobic residues (Phe) were replaced with other aromatic residues (phenylglycine (Phg

• . All the CSP1 analogs were synthesized on a 4-benzyloxybenzyl alcohol (Wang) resin (0.65 mmol/g) pre-loaded with Fmoc-L-Lys(Boc). With the exception of the phenylglycine and norvaline derivatives, the CSP1 analogs were synthesized using standard Fmoc-based solid-phase peptide synthesis (SPPS

• ) procedures [34]. Phenylglycine and norvaline derivatives were prepared on a CEM Discover microwave synthesizer, with diisopropyl carbodiimide (DIC) as the coupling reagent along with Oxyma Pure. The ratio of DIC:Oxyma Pure:AA was 3.6:3:3 dissolved in N,N-dimethylformamide (DMF) for a final DIC concentration

[3 + 2]-Cycloaddition reaction of sydnones with alkynes

• Veronika Hladíková,
• Jiří Váňa and
• Jiří Hanusek

Beilstein J. Org. Chem. 2018, 14, 1317–1348, doi:10.3762/bjoc.14.113

• applications. Moreover, a further improvement was later devised by the same authors, which avoids the highly toxic N-nitroso-N-phenylglycine, (precursor of sydnone) and involves a three-step one-pot transformation of starting N-phenylglycine to the corresponding pyrazole [118]. There are several limitations of

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

• Boc-Tyr-ψ[(Z)-CF=CH]-Gly using a diastereoselective Reformatsky–Honda condensation, a (E)-selective HWE olefination and a SmI2 reduction as key steps (Scheme 12) [41]. First, Reformatsky–Honda reaction of TIPS-protected phenylacetaldehyde 57 with the chiral auxiliary (L)-phenylglycine derivative 58

Asymmetric synthesis of propargylamines as amino acid surrogates in peptidomimetics

• Matthias Wünsch,
• David Schröder,
• Tanja Fröhr,
• Lisa Teichmann,
• Sebastian Hedwig,
• Nils Janson,
• Clara Belu,
• Jasmin Simon,
• Shari Heidemeyer,
• Philipp Holtkamp,
• Jens Rudlof,
• Lennard Klemme,
• Alessa Hinzmann,
• Beate Neumann,
• Hans-Georg Stammler and
• Norbert Sewald

Beilstein J. Org. Chem. 2017, 13, 2428–2441, doi:10.3762/bjoc.13.240

• , phenylglycine and tyrosine) have been prepared using a large excess (4 equivalents) of [(trimethylsilyl)ethynyl]dimethylaluminum as the nucleophile [14][48][52]. The reaction of the sulfinylimines 5 with (trimethylsilyl)ethynyllithium provided the crude intermediates 6, which were converted into the N-sulfinyl

• additionally increase the acidity of the α-proton. Nevertheless, glycine derivatives with electron-withdrawing substituents like formylglycine [58][59], phenylglycine [60][61] and fluorinated alanine [62][63][64] have attracted great attention as peptidomimetics, drugs or in the bioorthogonal functionalization

Development of a method for the synthesis of 2,4,5-trisubstituted oxazoles composed of carboxylic acid, amino acid, and boronic acid

• Kohei Yamada,
• Naoto Kamimura and
• Munetaka Kunishima

Beilstein J. Org. Chem. 2017, 13, 1478–1485, doi:10.3762/bjoc.13.146

• substitution pattern at the 4-position of the oxazole. The one-pot oxazole synthesis with phenylalanine (2b), valine (2c), leucine (2d), methionine (2e), and phenylglycine (2f) proceeded to give the corresponding intermediates in good yields (Table 1, entries 6–10). Despite the existence of highly polar

Phosphated cyclodextrins as water-soluble chiral NMR solvating agents for cationic compounds

• Cira Mollings Puentes and
• Thomas J. Wenzel

Beilstein J. Org. Chem. 2017, 13, 43–53, doi:10.3762/bjoc.13.6

• )cyclohexanemethanol (13), alanine methyl ester (14), 2-phenylglycine methyl ester (15), phenylalanine methyl ester (16), tyrosine (17), 4-chlorophenylalanine methyl ester (18), 4-chlorophenylalanine ethyl ester (19), carbobenzyloxy serine (20), 2-methylindoline (21), trans-1-amino-2-indanol (22), cis-1-amino-2

Synthesis, fluorescence properties and the promising cytotoxicity of pyrene–derived aminophosphonates

• Jarosław Lewkowski,
• Maria Rodriguez Moya,
• Anna Wrona-Piotrowicz,
• Janusz Zakrzewski,
• Renata Kontek and
• Gabriela Gajek

Beilstein J. Org. Chem. 2016, 12, 1229–1235, doi:10.3762/bjoc.12.117

• phosphonic analogues of phenylglycine, exhibited their herbicidal activity [10], and are used as plant growth regulators [10], agrochemical fungicides [11][12] and glutamate receptor modulators [13]. It is therefore expectable that C-pyrene derivatives may have similar or even more promising biological

Organocatalytic asymmetric Henry reaction of 1H-pyrrole-2,3-diones with bifunctional amine-thiourea catalysts bearing multiple hydrogen-bond donors

• Ming-Liang Zhang,
• Deng-Feng Yue,
• Zhen-Hua Wang,
• Yuan Luo,
• Xiao-Ying Xu,
• Xiao-Mei Zhang and
• Wei-Cheng Yuan

Beilstein J. Org. Chem. 2016, 12, 295–300, doi:10.3762/bjoc.12.31

• bifunctional, thiourea-tertiary amine catalyst 3b, derived from quinine and L-valine, furnished a similar result to catalyst 3a (Table 1, entry 2). Next, the reaction was attempted with catalyst 3c derived from L-phenylalanine and catalyst 3d derived from L-phenylglycine, and improvements in enantioselectivity

A novel family of (1-aminoalkyl)(trifluoromethyl)- and -(difluoromethyl)phosphinic acids – analogues of α-amino acids

• Natalia V. Pavlenko,
• Tatiana I. Oos,
• Yurii L. Yagupolskii,
• Igor I. Gerus,
• Uwe Doeller and
• Lothar Willms

Beilstein J. Org. Chem. 2014, 10, 722–731, doi:10.3762/bjoc.10.66

• proteinogenic and nonproteinogenic α-amino acids were prepared. The synthetic methodology was based on nucleophilic addition of (trifluoromethyl)phosphinic acid or (difluoromethyl)phosphinic acid or its ethyl ester to substrates with C=N or activated C=C double bonds. Analogues of glycine, phenylglycine

• . This resulted in the preparation of the analogues of glycine 14a and phenylglycine 14b (Scheme 3). The three-component reaction with formaldehyde gave the best results and N-protected aminophosphinic acid 13a was isolated in a moderate yield, alongside phosphonic acid 10. The analogous reaction with

• (1) to a series of N-benzylimines 16a–e in order to obtain fluorinated phosphorus analogues of glycine 14a, phenylglycine 14b, alanine 14c, valine 14d and proline 14e (Table 1). The transformations were mildly exothermic and were monitored by 31P NMR. Acid 1 undergoes the typical P–C bond forming

Concise, stereodivergent and highly stereoselective synthesis of cis- and trans-2-substituted 3-hydroxypiperidines – development of a phosphite-driven cyclodehydration

• Peter H. Huy,
• Julia C. Westphal and
• Ari M. P. Koskinen

Beilstein J. Org. Chem. 2014, 10, 369–383, doi:10.3762/bjoc.10.35

• , phenylalanine, phenylglycine and methionine 1a–d were converted to their N-benzyl-N-carbamate-protected derivatives 2a–d (PG = Cbz, Boc) in a practical one pot procedure through combination of Quitt´s reductive benzylation protocol [61] and a Schotten–Baumann acylation [62][63] in 70–95% yield (Scheme 1). While

• and 2d (Et3N/DMAP or NMM as bases; Table 1, entries 1 and 2), the protected phenylglycine derivative 2c showed high configurational lability: Under standard conditions (DCC/Et3N/0.3 equiv DMAP) the amide 5c was obtained in a diminished ee of 49% (Table 1, entry 3). HOBt as nucleophilic catalyst proved

• condensation product 5c was formed in a moderate ee of 74% (Table 1, entry 7). The configurational lability of the phenylglycine derivative was not surprising, as phenylglycine itself is 60 times more prone to racemisation than alanine [68]. The optical purity of amides 5a–c, hydroxyketone 7c and piperidins

Synthesis of conformationally restricted glutamate and glutamine derivatives from carbonylation of orthopalladated phenylglycine derivatives

• Esteban P. Urriolabeitia,
• Eduardo Laga and
• Carlos Cativiela

Beilstein J. Org. Chem. 2012, 8, 1569–1575, doi:10.3762/bjoc.8.179

• results, however, in the formation of the cyclic isoindolinone or the open 2-carboxyphenylglycine methyl esters, with the reaction outcome being driven by the choice of the solvent. Keywords: C–H functionalization; carbonylation; glutamic acid; glutamide; palladium; phenylglycine; Introduction The

• case of alcohols, primary (2a, 2b, 2d, 2e) and secondary (2c) aliphatic alcohols, and even arylic substrates (2f) have been incorporated into the phenylglycine scaffold. Very good yields are obtained with acidic alcohols, such as methanol (2a), ethanol (2b) or even 1,2-ethanediol (2d). These values

• related alkoxycarbonylation reaction [25][26][27][28][29][30]. Once we had determined the reactivity of complex 1, having a N,N-dimethyl-phenylglycine ligand, we focused our attention on complex 3, possessing a triflate as a N-protecting group, in order to study the influence of the substituents at the N

Anthracene appended pyridinium amide–urea conjugate in selective fluorometric sensing of L-N-acetylvaline salt

• Kumaresh Ghosh,
• Tanmay Sarkar and
• Asoke P. Chattopadhyay

Beilstein J. Org. Chem. 2010, 6, 1211–1218, doi:10.3762/bjoc.6.139

• excited state of anthracene is regulated in different ways. We presume that receptor 1 may follow any equilibrium-binding mode A, B or C with valine, alanine and phenylglycine salts in solution as shown in Figure 5. This is also true for the mandelate, pyruvate and proline salts. Relevance of the

• such as the salts of valine, phenylglycine and mandelic acid exhibit the lowest values of ω among all anionic guests considered. This indicates that these guests have higher nucleophilic character compared to the other guests studied. Therefore, receptor 1, in principle, will show strong binding for

Towards racemizable chiral organogelators

• Jian Bin Lin,
• Debarshi Dasgupta,
• Seda Cantekin and
• Albertus P. H. J. Schenning

Beilstein J. Org. Chem. 2010, 6, 960–965, doi:10.3762/bjoc.6.107

• of 0.25 M HCl solution and the aqueous solution extracted two times with 1 mL of CHCl3. The remaining aqueous solution of phenylglycine amide HCl salt was used as such for the ee determination by the following HPLC method. Column; crownether Cr (+) 150 x 4.6 mm ID, eluent; aqueous HClO4 pH = 1.2

Molecular recognition of organic ammonium ions in solution using synthetic receptors

• Andreas Späth and
• Burkhard König

Beilstein J. Org. Chem. 2010, 6, No. 32, doi:10.3762/bjoc.6.32

• salts with binding affinities Kass up to 4.8 × 105 M−1 in CH2Cl2 with 0.25% CH3OH. The bpy-crown macrocycle with n = 1, reflecting the pseudo 18-crown-6 type structure, exhibited the best properties and the highest enantioselectivity towards the S-enantiomer of phenylglycine methyl ester hydrochloride