Recent applications of porphyrins as photocatalysts in organic synthesis: batch and continuous flow approaches

• Rodrigo Costa e Silva,
• Luely Oliveira da Silva,
• Aloisio de Andrade Bartolomeu,
• Timothy John Brocksom and
• Kleber Thiago de Oliveira

Beilstein J. Org. Chem. 2020, 16, 917–955, doi:10.3762/bjoc.16.83

• biologically active compounds [104]. These compounds can be trapped with nucleophiles to produce the α-amino-substituted compounds, and be employed as substrates for a variety of chemical transformations such as Ugi- and Mannich-type reactions. In this regard, Seeberger and co-workers reported the primary

Preparation of 2-phospholene oxides by the isomerization of 3-phospholene oxides

• Péter Bagi,
• Réka Herbay,
• Nikolett Péczka,
• Zoltán Mucsi,
• István Timári and
• György Keglevich

Beilstein J. Org. Chem. 2020, 16, 818–832, doi:10.3762/bjoc.16.75

• importance for biologically active compounds, as specific functional groups are necessary to have a desired biological activity. Considering the functionalization of the five-membered P-heterocycles, the derivatives containing double bond(s) (i.e., phospholenes or phospholes) are of special importance, as a

Efficient synthesis of piperazinyl amides of 18β-glycyrrhetinic acid

• Dong Cai,
• ZhiHua Zhang,
• Yufan Meng,
• KaiLi Zhu,
• LiYi Chen,
• ChangXiang Yu,
• ChangWei Yu,
• ZiYi Fu,
• DianShen Yang and
• YiXia Gong

Beilstein J. Org. Chem. 2020, 16, 798–808, doi:10.3762/bjoc.16.73

• %) without the formation of byproducts [21]. Given the flexible 18β-glycyrrhetinic acid scaffold in the design of biologically active compounds, a novel and efficient method was reported to prepare C3 ester derivatives or/and C30 piperazinyl amides (c). 18β-Glycyrrhetinic acid belongs to the class of ursane

Efficient synthesis of dipeptide analogues of α-fluorinated β-aminophosphonates

• Marcin Kaźmierczak and
• Henryk Koroniak

Beilstein J. Org. Chem. 2020, 16, 756–762, doi:10.3762/bjoc.16.69

• biologically active compounds. As an example, we can consider peptide bond formation between an amine and a carboxylic acid. This transformation is a very important reaction in organic synthesis and therefore, many coupling reagents are available on the market [25][26][27][28][29]. Our previous studies have

Synthesis of 4-(2-fluorophenyl)-7-methoxycoumarin: experimental and computational evidence for intramolecular and intermolecular C–F···H–C bonds

• Vuyisa Mzozoyana,
• Fanie R. van Heerden and
• Craig Grimmer

Beilstein J. Org. Chem. 2020, 16, 190–199, doi:10.3762/bjoc.16.22

• of biologically active compounds as it imparts a variety of properties such as enhanced binding interaction, metabolic stability, and reaction selectivity by changing physical and chemical properties [23][24][25][26]. Hydrogen bonds (HBs) are associated with highly electronegative atoms (oxygen

Rapid, two-pot procedure for the synthesis of dihydropyridinones; total synthesis of aza-goniothalamin

• Thomas J. Cogswell,
• Craig S. Donald and
• Rodolfo Marquez

Beilstein J. Org. Chem. 2020, 16, 135–139, doi:10.3762/bjoc.16.15

• biologically active compounds. As a result, their synthesis has received extensive research and wide spread publication in the literature [1][2][3][4][5][6]. Dihydropyridinones are an important subclass of heterocycles, which often feature both as useful intermediates, and as interesting species in their own

Extension of the 5-alkynyluridine side chain via C–C-bond formation in modified organometallic nucleosides using the Nicholas reaction

• Renata Kaczmarek,
• Dariusz Korczyński,
• James R. Green and
• Roman Dembinski

Beilstein J. Org. Chem. 2020, 16, 1–8, doi:10.3762/bjoc.16.1

• warranted, which at the same time may provide biologically active compounds. Results and Discussion Preparation of 5-alkynyluridines was carried out from acyl-protected 5-iodouridines (1a,b) [8][63] and the appropriate terminal alkyne in the presence of catalytic amounts of Pd(PPh3)4, copper(I) iodide

Why do thioureas and squaramides slow down the Ireland–Claisen rearrangement?

• Dominika Krištofíková,
• Juraj Filo,
• Mária Mečiarová and
• Radovan Šebesta

Beilstein J. Org. Chem. 2019, 15, 2948–2957, doi:10.3762/bjoc.15.290

• base [1][2][3]. The products of the Ireland–Claisen rearrangement, γ,δ-unsaturated acids, are useful precursors of biologically active compounds and natural products [4][5][6][7][8][9][10][11]. The ready availability of allylic esters, the ability to control the E/Z geometry of enolates as well as its

Facile regiodivergent synthesis of spiro pyrrole-substituted pseudothiohydantoins and thiohydantoins via reaction of [e]-fused 1H-pyrrole-2,3-diones with thiourea

• Aleksandr I. Kobelev,
• Nikita A. Tretyakov,
• Ekaterina E. Stepanova,
• Maksim V. Dmitriev,
• Michael Rubin and
• Andrey N. Maslivets

Beilstein J. Org. Chem. 2019, 15, 2864–2871, doi:10.3762/bjoc.15.280

• good yields, and the products were isolated without applying preparative chromatography methods. Keywords: diversity-oriented synthesis; hydantoin; nitrogen heterocycles; rearrangement; thiourea; Introduction Hydantoin (imidazolidine-2,4-dione) derivatives are omnipresent among biologically active

• compounds [1]. Many of them are commercially available drugs, for example, anticonvulsants phenytoin [2] and albutoin [3], the muscle relaxant dantrolene [4], or the nonsteroidal antiandrogen agent enzalutamide [5] (Figure 1). Despite this fact, hydantoin derivatives belong to a special group of scaffolds

Skeletocutins M–Q: biologically active compounds from the fruiting bodies of the basidiomycete Skeletocutis sp. collected in Africa

• Tian Cheng,
• Clara Chepkirui,
• Cony Decock,
• Josphat C. Matasyoh and
• Marc Stadler

Beilstein J. Org. Chem. 2019, 15, 2782–2789, doi:10.3762/bjoc.15.270

Diversity-oriented synthesis of spirothiazolidinediones and their biological evaluation

• Sambasivarao Kotha,
• Gaddamedi Sreevani,
• Lilya U. Dzhemileva,
• Milyausha M. Yunusbaeva,
• Usein M. Dzhemilev and
• Vladimir A. D’yakonov

Beilstein J. Org. Chem. 2019, 15, 2774–2781, doi:10.3762/bjoc.15.269

• represent an important class of nitrogen-containing biologically active compounds which exhibit various biological properties, such as antiviral, antibacterial and anticancer, etc. [55][56][57][58]. Recently, the use of 1,2,3-triazole derivatives as drug candidates has been increased for clinical therapy of

Friedel–Crafts approach to the one-pot synthesis of methoxy-substituted thioxanthylium salts

• Kenta Tanaka,
• Yuta Tanaka,
• Mami Kishimoto,
• Yujiro Hoshino and
• Kiyoshi Honda

Beilstein J. Org. Chem. 2019, 15, 2105–2112, doi:10.3762/bjoc.15.208

• . Keywords: Friedel–Crafts reaction; metal-free conditions; one-pot synthesis; photoredox catalyst; thioxanthylium salt; Introduction Thioxanthylium salts are one of the important structural motifs found in biologically active compounds and photochemical materials [1][2][3][4][5][6][7][8]. Owing to these

Installation of -SO₂F groups onto primary amides

• Jing Liu,
• Shi-Meng Wang,
• Njud S. Alharbi and
• Hua-Li Qin

Beilstein J. Org. Chem. 2019, 15, 1907–1912, doi:10.3762/bjoc.15.186

• , and a vast number of synthetic structures, such as polymers, biologically active compounds and pharmaceutical products [32][33][34][35]. However, the installation of sulfonyl fluoride (SO2F) onto nitrogen atoms of amides has not been achieved, which, if accomplished, would provide a very important

N-(1-Phenylethyl)aziridine-2-carboxylate esters in the synthesis of biologically relevant compounds

• Iwona E. Głowacka,
• Aleksandra Trocha,
• Andrzej E. Wróblewski and
• Dorota G. Piotrowska

Beilstein J. Org. Chem. 2019, 15, 1722–1757, doi:10.3762/bjoc.15.168

Recent advances on the transition-metal-catalyzed synthesis of imidazopyridines: an updated coverage

• Gagandeep Kour Reen,
• Ashok Kumar and
• Pratibha Sharma

Beilstein J. Org. Chem. 2019, 15, 1612–1704, doi:10.3762/bjoc.15.165

• heterocycles have blossomed in the last many years. These heterocyclic scaffolds occupy a pivotal role in the realm of both natural products and synthetic organic chemistry. Their importance as precursors to many biologically active compounds has created a tremendous amount of focused attention on developing

Synthesis of aryl cyclopropyl sulfides through copper-promoted S-cyclopropylation of thiophenols using cyclopropylboronic acid

• Emeline Benoit,
• Ahmed Fnaiche and
• Alexandre Gagnon

Beilstein J. Org. Chem. 2019, 15, 1162–1171, doi:10.3762/bjoc.15.113

• thiophenol was also accomplished using potassium cyclopropyl trifluoroborate. Keywords: aryl cyclopropyl sulfides; copper(II) acetate; copper catalysis; cyclopropylboronic acid; thiophenols; Introduction Aryl cyclopropyl sulfides are present in many biologically active compounds, mainly in their oxidized

Multicomponent reactions (MCRs): a useful access to the synthesis of benzo-fused γ-lactams

• Edorta Martínez de Marigorta,
• Jesús M. de Los Santos,
• Ana M. Ochoa de Retana,
• Javier Vicario and
• Francisco Palacios

Beilstein J. Org. Chem. 2019, 15, 1065–1085, doi:10.3762/bjoc.15.104

• -oxindoles; Introduction Pyrrolidin-2-ones (I, Figure 1) are heterocycles that contain a γ-lactam ring that can be found in many biologically active compounds with natural or synthetic origin [1]. When an aryl group is fused to the 3- and 4-positions of the five-membered heterocycle, isoindolinones (II

• using simple substrates and reagents. γ-Lactam-derived structures considered in this review. Alkaloids containing an isoindolinone moiety. Alkaloids containing the 2-oxindole ring system. Drugs and biological active compounds containing an isoindolinone moiety. Drugs and biologically active compounds

New sesquiterpenoids from the South China Sea soft corals Clavularia viridis and Lemnalia flava

• Qihao Wu,
• Yuan Gao,
• Meng-Meng Zhang,
• Li Sheng,
• Jia Li,
• Xu-Wen Li,
• Hong Wang and
• Yue-Wei Guo

Beilstein J. Org. Chem. 2019, 15, 695–702, doi:10.3762/bjoc.15.64

• ; Introduction Marine soft corals are important sources of biologically active compounds, which made them attractive targets for natural product chemists. Soft corals of the genus Clavularia (class Octocorallia, order Alcyonacea, family Clavulariidea), are prolific sources of numerous biologically active

• compounds [1][2][3][4]. A variety of structurally unique sesquiterpenes, including aromadendranes [5], maalianes [5], elemanes [6], and trinor-guaianes [7][8][9], have been isolated since the early 1980s from several species of Clavularia. Soft corals of the genus Lemnalia are also a rich source of

Synthesis of 2H-furo[2,3-c]pyrazole ring systems through silver(I) ion-mediated ring-closure reaction

• Vaida Milišiūnaitė,
• Rūta Paulavičiūtė,
• Eglė Arbačiauskienė,
• Vytas Martynaitis,
• Wolfgang Holzer and
• Algirdas Šačkus

Beilstein J. Org. Chem. 2019, 15, 679–684, doi:10.3762/bjoc.15.62

• systems possessing a pyrazole ring fused to an oxygen-containing six-membered heterocycle are present in a wide variety of biologically active compounds. For example, the 1,4- and 2,4-dihydropyrano[2,3-c]pyrazole ring systems [1] often represent the main structural motifs of anticancer [2][3][4], anti

• alkoxide [11]. Notably, the 2H-furo[2,3-c]pyrazole ring system is structurally similar to the benzo[b]furan system, which is a privileged motif in natural products and biologically active compounds [13][14]. As a result, numerous strategies have been developed for the construction of benzo[b]furan and its

Asymmetric synthesis of a high added value chiral amine using immobilized ω-transaminases

• Antonella Petri,
• Valeria Colonna and
• Oreste Piccolo

Beilstein J. Org. Chem. 2019, 15, 60–66, doi:10.3762/bjoc.15.6

• sustainable approach to an industrial scale. Keywords: asymmetric catalysis; biotransformations; chiral amine; immobilized enzymes; ω-transaminases; Introduction Enantiomerically pure amines are important precursors to biologically active compounds with different industrial applications, including

• intermediates for the synthesis of a large number of biologically active compounds used for the treatment of obesity, type-I and II diabetes mellitus or as psychotropic drugs against depression and schizophrenia [15][16][17][18][19]. In particular (R)-3-amino-1-Boc-piperidine is a useful precursor of compounds

A tutorial review of stereoretentive olefin metathesis based on ruthenium dithiolate catalysts

• Daniel S. Müller,
• Olivier Baslé and
• Marc Mauduit

Beilstein J. Org. Chem. 2018, 14, 2999–3010, doi:10.3762/bjoc.14.279

• stereochemical purity. We applied the in situ generated catalyst to several reactions including cross metathesis, self-metathesis and RCM reactions. The selectivities are in general very high (Z/E = 98:2 or higher). 8 Applications in the synthesis of biologically active compounds Several biologically active

• compounds, fragrance molecules and natural products were synthesized utilizing stereoretentive metathesis based on Ru-dithiolate catalysts, for example (+)-neopeltolide (53, Figure 6) [24]. For each of the examples the catalyst loading of the Ru-dithiolate catalyst which was required to forge the

D-Fructose-based spiro-fused PHOX ligands: synthesis and application in enantioselective allylic alkylation

• Michael R. Imrich,
• Jochen Kraft,
• Cäcilia Maichle-Mössmer and
• Thomas Ziegler

Beilstein J. Org. Chem. 2018, 14, 2082–2089, doi:10.3762/bjoc.14.182

• acetate as model substrate. Keywords: Fürst–Plattner rule; oxazoline; Ritter reaction; Tsuji–Trost reaction; Ullmann coupling; Introduction The vast majority of biologically active compounds like vitamins and natural products occur as single enantiomers in nature. Usually only one enantiomer generates

Applications of organocatalysed visible-light photoredox reactions for medicinal chemistry

• Michael K. Bogdos,
• Emmanuel Pinard and
• John A. Murphy

Beilstein J. Org. Chem. 2018, 14, 2035–2064, doi:10.3762/bjoc.14.179

• oxidant (Scheme 22) [67]. Heterocycles in drugs are not only restricted to five-membered rings. Pyridines, pyrazines, pyrimidines, pyridazines are all common functional groups in biologically active compounds. Liu et al. have published the visible light-catalysed oxidation of dihydropyrimidines (DHPMs

Cationic cobalt-catalyzed [1,3]-rearrangement of N-alkoxycarbonyloxyanilines

• Itaru Nakamura,
• Mao Owada,
• Takeru Jo and
• Masahiro Terada

Beilstein J. Org. Chem. 2018, 14, 1972–1979, doi:10.3762/bjoc.14.172

• catalyst; concerted reaction; N–O bond; rearrangement; Introduction The 2-aminophenol moiety is ubiquitously found as a core structure of biologically active compounds, such as tigecycline [1], iguratimod [2], and phosalone (Scheme 1) [3]. The scaffolds have also been frequently utilized as synthetic

Synthesis of pyrimido[1,6-a]quinoxalines via intermolecular trapping of thermally generated acyl(quinoxalin-2-yl)ketenes by Schiff bases

• Svetlana O. Kasatkina,
• Ekaterina E. Stepanova,
• Maksim V. Dmitriev,
• Ivan G. Mokrushin and
• Andrey N. Maslivets

Beilstein J. Org. Chem. 2018, 14, 1734–1742, doi:10.3762/bjoc.14.147

• (quinoxaline fused by a six-membered heterocycle at the [a]-side) are promising biologically active compounds. Recent research studies revealed that they can act as inhibitors of poly(ADP-ribose) polymerase (PARP) [3], inhibitors of hepatitis C virus [4], 5-HT2C agonists [5][6][7], substances for controlling

• catalysts. The elaborated method might be applicable to the syntheses of pharmaceutically important substances. Quinoxaline-based 6/6/6-angularly fused scaffolds and respective examples of biologically active compounds. Synthetic routes towards the pyrimido[1,6-a]quinoxaline scaffold. Acyl(quinoxalin-2-yl