Generation of multimillion chemical space based on the parallel Groebke–Blackburn–Bienaymé reaction

• Evgen V. Govor,
• Vasyl Naumchyk,
• Ihor Nestorak,
• Dmytro S. Radchenko,
• Dmytro Dudenko,
• Yurii S. Moroz,
• Olexiy D. Kachkovsky and
• Oleksandr O. Grygorenko

Beilstein J. Org. Chem. 2024, 20, 1604–1613, doi:10.3762/bjoc.20.143

• ., 3-aminopyrazole (1{1}), 3-aminoisoxazole (1{2}), 2-aminothiazole (1{3}), 2-amino-1,3,4-thiadiazole (1{4}), or 2-aminotetrazole (1{5}) demonstrated poor conversion to the target products; 2-aminopyrimidines either gave isomeric mixtures (e.g., parent compound 1{6}, alkyl-substituted derivatives 1{7

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

Double-headed nucleosides: Synthesis and applications

• Vineet Verma,
• Jyotirmoy Maity,
• Vipin K. Maikhuri,
• Ritika Sharma,
• Himal K. Ganguly and
• Ashok K. Prasad

Beilstein J. Org. Chem. 2021, 17, 1392–1439, doi:10.3762/bjoc.17.98

• -triazolo[3,4-b](1,3,4)-thiadiazole moieties [21]. Additionally, selected examples of double-headed nucleosides comprising aromatic/polyaromatic/carbocyclic moieties such as phenyl [13][14][15][22], pyrene [23][24][25], adamant-1-yl [24], cholesteryl [24], perylen-3-yl [24], 4-(tert-butyldimethylsilyloxy

Synthesis of ([1,2,4]triazolo[4,3-a]pyridin-3-ylmethyl)phosphonates and their benzo derivatives via 5-exo-dig cyclization

• Aleksandr S. Krylov,
• Artem A. Petrosian,
• Julia L. Piterskaya,
• Nataly I. Svintsitskaya and
• Albina V. Dogadina

Beilstein J. Org. Chem. 2019, 15, 1563–1568, doi:10.3762/bjoc.15.159

• when using C,N-, N,S- and N,N-dinucleophiles. It is characterized by a selective 5-endo-dig cyclization to the corresponding five-membered rings. The obtained new compounds are of special interest due to the practical utility of the formed fused heterocycles, such as indoles [1], thiazolo[2,3-b][1,3,4

• ]thiadiazole [2], and benzo[4,5]imidazo[2,1-b]thiazole [3], as well as due to the simultaneous presence of a biologically active phosphorus function in the molecules. Recently, we have shown that the reaction of chloroethynylphosphonates with 2-aminopyridines proceeds through a 5-endo-dig cyclization to form

Dialkyl dicyanofumarates and dicyanomaleates as versatile building blocks for synthetic organic chemistry and mechanistic studies

• Grzegorz Mlostoń and
• Heinz Heimgartner

Beilstein J. Org. Chem. 2017, 13, 2235–2251, doi:10.3762/bjoc.13.221

• similar transfer of a carbene unit was presented to explain the formation of cyclopropanes 15 in the reaction of E- and Z-1b with the in situ generated thiocarbonyl S-isopropanide 16a. The latter is formed through a thermal N2 elimination from 2,5-dihydro-1,3,4-thiadiazole 17a [24][25] (Scheme 5). The

• cyclopropane derivatives. The treatment of methyl 3-methyl-2-oxodithiobutanoate with diazomethane at −80 °C in hexane/CH2Cl2 afforded the expected 2-sulfanyl-2-isobutanoyl-2,5-dihydro-1,3,4-thiadiazole. After the addition of E-1a and warming of the mixture to room temperature, the corresponding thiolane as the

A novel application of 2-silylated 1,3-dithiolanes for the synthesis of aryl/hetaryl-substituted ethenes and dibenzofulvenes

• Grzegorz Mlostoń,
• Paulina Pipiak,
• Róża Hamera-Fałdyga and
• Heinz Heimgartner

Beilstein J. Org. Chem. 2017, 13, 1900–1906, doi:10.3762/bjoc.13.185

• ]. For example, in contrast to thiobenzophenone (1a), phenyl selenophen-2-yl thioketone (1b) does not form the corresponding 2,5-dihydro-1,3,4-thiadiazole of type 2, and even at −70 °C spontaneous elimination of N2 was observed. As products of this reaction, dimer 4 of the intermediate thiocarbonyl S

Synthesis and optical properties of new 5'-aryl-substituted 2,5-bis(3-decyl-2,2'-bithiophen-5-yl)-1,3,4-oxadiazoles

• Anastasia S. Kostyuchenko,
• Tatyana Yu. Zheleznova,
• Anton J. Stasyuk,
• Aleksandra Kurowska,
• Wojciech Domagala,
• Adam Pron and
• Alexander S. Fisyuk

Beilstein J. Org. Chem. 2017, 13, 313–322, doi:10.3762/bjoc.13.34

• enables the preparation of linear D–A–D compounds with one or two 1,3,4-oxadiazole [16][17][18][19], 1,3,4-thiadiazole [16][18][19][20][21][22] or 1,2,4-triazole [16][18] central rings symmetrically disubstituted with alkylbithiophene 1, 2 as well as star-shaped molecules with D–A arms 3 (Figure 1) [23

Synthesis of ferrocenyl-substituted 1,3-dithiolanes via [3 + 2]-cycloadditions of ferrocenyl hetaryl thioketones with thiocarbonyl S-methanides

• Grzegorz Mlostoń,
• Róża Hamera-Fałdyga,
• Anthony Linden and
• Heinz Heimgartner

Beilstein J. Org. Chem. 2016, 12, 1421–1427, doi:10.3762/bjoc.12.136

• -Tetramethyl-8-thia-5,6-diazaspiro[3.4]oct-5-en-2-one (3c) [20] and spiro[1,3,4-thiadiazole-2(5H),2’-tricyclo[3.3.1.13,7]decane] (3d) [21] were obtained by known methods according to the literature protocols. Diazomethane was prepared in a 5 mmol scale either from N-nitroso-N-methylurea or from N

Facile synthesis of 1H-imidazo[1,2-b]pyrazoles via a sequential one-pot synthetic approach

• András Demjén,
• Márió Gyuris,
• János Wölfling,
• László G. Puskás and
• Iván Kanizsai

Beilstein J. Org. Chem. 2014, 10, 2338–2344, doi:10.3762/bjoc.10.243

• -aminoazoles, including thiazole [13][14] and 1,3,4-thiadiazole [15][16] derivatives, or 2-aminoazine-based heterocycles, such as pyridines [17][18][19], pyrimidines [20][21][22][23][24] and pyrazines [25][26][27], have recently been utilized as Groebke–Blackburn–Bienaymé three-component reaction (GBB-3CR

Multicomponent reactions in nucleoside chemistry

• Mariola Koszytkowska-Stawińska and
• Włodzimierz Buchowicz

Beilstein J. Org. Chem. 2014, 10, 1706–1732, doi:10.3762/bjoc.10.179

• was conducted under solvent-free microwave irradiation conditions. Products 114 were isolated by crystallization in yields exceeding 80%. Siddiqui et al. developed the method for the preparation of nucleoside analogs 116 with the 1,3,4-thiadiazole-derived nucleobase. This method involved the microwave

Synthesis of new, highly luminescent bis(2,2’-bithiophen-5-yl) substituted 1,3,4-oxadiazole, 1,3,4-thiadiazole and 1,2,4-triazole

• Anastasia S. Kostyuchenko,
• Vyacheslav L.Yurpalov,
• Aleksandra Kurowska,
• Wojciech Domagala,
• Adam Pron and
• Alexander S. Fisyuk

Beilstein J. Org. Chem. 2014, 10, 1596–1602, doi:10.3762/bjoc.10.165

• functionalised oligothiophenes, coupled to other heteroaromatic cores. Keywords: bithiophene; donor–acceptor; luminescence; 1,3,4-oxadiazole; 1,3,4-thiadiazole; 4H-1,2,4-triazole; Introduction In the past two decades oligo- and polythiophenes gained a significant research interest due to their wide application

• that 1,3,4-oxadiazoles [26], 1,3,4-thiadiazole [27] and 1,2,4-triazoles [28][29][30] can be obtained from diacylhydrazines. Thus, 11 and 12 were converted to 2,5-bis(3-decyl-2,2'-bithiophen-5-yl)-1,3,4-oxadiazole (13) and 2,5-bis[4-(hexyloxy)-2,2'-bithiophen-5-yl]-1,3,4-oxadiazole (14) by the reaction

• photoluminescence quantum yields are indicated together with the formulae of the corresponding compounds. In the case of 18 (4-phenyl-4H-1,2,4-triazole ring) the photoluminescence quantum yield is almost three times higher than that measured for 15 (1,3,4-thiadiazole ring). The obtained results clearly demonstrate

Liquid-crystalline heterodimesogens and ABA-heterotrimesogens comprising a bent 3,5-diphenyl-1,2,4-oxadiazole central unit

• Govindaswamy Shanker,
• Marko Prehm and
• Carsten Tschierske

Beilstein J. Org. Chem. 2012, 8, 472–485, doi:10.3762/bjoc.8.54

• terminally connected ABA-heterotrimesogens and heterodimesogens, composed of a bent 3,5-diphenyl-1,2,4-oxadiazole central unit and one or two rod-shaped 4-cyanobiphenyl cores or one 2-phenyl-1,3,4-thiadiazole core, connected by flexible spacers, have been synthesized, and their mesomorphic behavior was

• -1,3,4-thiadiazole unit is incorporated (Scheme 3). All compounds form nematic phases over wide temperature ranges, in some cases accompanied by additional nontilted (CybA) or tilted (SmC) mesophases at lower temperatures. Results and Discussion Synthesis and characterization The dimesogens and

• distinct from that of compounds CB-Ox/n. Firstly, they have alkyl tails at both ends, and secondly, they incorporate a 1,3,4-thiadiazole unit, which is not strictly linear (bending angle 162°) [80] and within which the direction of the major dipole moment is perpendicular to the molecular long axis [80][81

Low temperature enantiotropic nematic phases from V-shaped, shape-persistent molecules

• Matthias Lehmann and
• Jens Seltmann

Beilstein J. Org. Chem. 2009, 5, No. 73, doi:10.3762/bjoc.5.73

• stirred for 2 h at room temperature. Subsequently, the solvent is removed in vacuo and the products are isolated by column chromatography using a mixture of EtOAc/hexane. 2-{4-[4-{4-[4-(Ethoxycarbonyl)butoxy]phenylethynyl}-2,5-bis(hexyloxy)phenyl]ethynylphenyl}-5-(4-bromophenyl)-1,3,4-thiadiazole (3a

• -(ethoxycarbonyl)butoxy]phenylethynyl}-2,5-bis(hexyloxy)phenyl]ethynylphenyl}-1,3,4-thiadiazole (1a) Hexane/EtOAc = 6/1 (Rf = 0.1), yellow solid; yield 120 mg (74%). 1H NMR (400 MHz, CDCl3): δ = 8.00 (4H, AA′BB′), 7.64 (4H, AA′BB′), 7.46 (4H, AA′BB′), 7.02 (s, 2H), 7.01 (s, 2H), 6.86 (4H, AA′BB′), 4.13 (q, 4H