Nucleophile-induced ring contraction in pyrrolo[2,1-c][1,4]benzothiazines: access to pyrrolo[2,1-b][1,3]benzothiazoles

• Ekaterina A. Lystsova,
• Maksim V. Dmitriev,
• Andrey N. Maslivets and
• Ekaterina E. Khramtsova

Beilstein J. Org. Chem. 2023, 19, 646–657, doi:10.3762/bjoc.19.46

• (Scheme 12) by an earlier procedure developed by us [51] in order to investigate the reaction optimization by HPLC–UV. Then, the reactant scope of the reaction was explored by involving to the reaction APBTTs 1a–h, bearing various aroyl substituents, and benzylamine (Scheme 13) [55]. As a result, we found

• us [51] in order to investigate the reaction optimization by HPLC-UV. After that, the reactant scope of the reaction was explored by involving to the reaction APBTTs 1a–h, bearing various aroyl substituents, and arylamines 11a–d, bearing aryl substituents with various electronic effects (Scheme 18

Strategies to access the [5-8] bicyclic core encountered in the sesquiterpene, diterpene and sesterterpene series

• Cécile Alleman,
• Charlène Gadais,
• Laurent Legentil and
• François-Hugues Porée

Beilstein J. Org. Chem. 2023, 19, 245–281, doi:10.3762/bjoc.19.23

• only in modest amounts even after extensive reaction times (more than 3 days) and high catalyst loadings (30–35 mol %). After reaction optimization, use of G-II catalyst allowed formation of cyclooctene 58 in excellent 90% yield. This compound could ultimately be advanced to 59 in 8 steps. Exhibiting a

NaI/PPh₃-catalyzed visible-light-mediated decarboxylative radical cascade cyclization of N-arylacrylamides for the efficient synthesis of quaternary oxindoles

• Dan Liu,
• Yue Zhao and
• Frederic W. Patureau

Beilstein J. Org. Chem. 2023, 19, 57–65, doi:10.3762/bjoc.19.5

• Discussion Key elements of reaction optimization are summarized in Table 1. With NaI (20 mol %) and PPh3 (20 mol %), acrylamide 1a and redox-active ester 2a were used as model substrates to react for 36 h in acetonitrile (MeCN) under blue LEDs irradiation and N2 atmosphere, delivering the desired oxindole

One-pot double annulations to confer diastereoselective spirooxindolepyrrolothiazoles

• Juan Lu,
• Bin Yao,
• Desheng Zhan,
• Zhuo Sun,
• Yun Ji and
• Xiaofeng Zhang

Beilstein J. Org. Chem. 2022, 18, 1607–1616, doi:10.3762/bjoc.18.171

• olefinic oxindole 4a shown in Table 1. In our continuous effort on the reaction optimization of benign solvents, we firstly evaluated the influence of reaction time and protic solvents such as EtOH, iPrOH and MeOH at 25 °C for 6 h, which only results in slightly different LC yield (93–95%) of compound 3a

Synthesis of meso-pyrrole-substituted corroles by condensation of 1,9-diformyldipyrromethanes with pyrrole

• Baris Temelli and
• Pinar Kapci

Beilstein J. Org. Chem. 2022, 18, 1403–1409, doi:10.3762/bjoc.18.145

• mono- and dipyrrole-substituted compounds. The reaction of 5-phenyl-1,9-diformyldipyrromethane (1a) with pyrrole. [2 + 2] Mac Donald type condensation reaction. Optimization of reaction conditions.a Synthesis of pyrrole-substituted corroles.a Supporting Information Supporting Information File 274

Heterogeneous metallaphotoredox catalysis in a continuous-flow packed-bed reactor

• Wei-Hsin Hsu,
• Susanne Reischauer,
• Peter H. Seeberger,
• Bartholomäus Pieber and
• Dario Cambié

Beilstein J. Org. Chem. 2022, 18, 1123–1130, doi:10.3762/bjoc.18.115

• point for applications in large-scale synthesis or automated reaction optimization. Based on literature precedents on catalyst leaching in packed-bed reactors [37][38], we assumed that the decreased activity could be linked to nickel leaching. Based on ICP results on the reactor outlet collected in the

• )-proline. Optimization of temperature and light intensity for the coupling of 4-iodobenzotrifluoride and sodium p-toluenesulfinate. Comparison of different reactors. Supporting Information Supporting Information File 104: Details of packed-bed assembly, experimental procedures, reaction optimization and

Electrogenerated base-promoted cyclopropanation using alkyl 2-chloroacetates

• Kouichi Matsumoto,
• Yuta Hayashi,
• Kengo Hamasaki,
• Mizuki Matsuse,
• Hiyono Suzuki,
• Keiji Nishiwaki and
• Norihito Kawashita

Beilstein J. Org. Chem. 2022, 18, 1116–1122, doi:10.3762/bjoc.18.114

• cyclopropanetricarboxylates. Previous reports (reactions 1–3) and this work (reaction 4). Plausible reaction mechanism. EGB = electrogenerated base. Reaction optimization. Effect of electricity around 1 F/mol and type of electrochemical cell. Scope and limitations. Scale-up experiments. Supporting Information Supporting

Electrochemical vicinal oxyazidation of α-arylvinyl acetates

• Yi-Lun Li,
• Zhaojiang Shi,
• Tao Shen and
• Ke-Yin Ye

Beilstein J. Org. Chem. 2022, 18, 1026–1031, doi:10.3762/bjoc.18.103

• (Ecell = 2.3 V, carbon cloth anode, and Pt cathode) of 1-phenylvinyl acetate (1) with azidotrimethylsilane was performed and the desired α-azidoketone (2) was obtained in 68% yield (Table 1, entry 1, for details of the reaction optimization see Supporting Information File 1). The cyclic voltammetry

On Reuben G. Jones synthesis of 2-hydroxypyrazines

• Pierre Legrand and
• Yves L. Janin

Beilstein J. Org. Chem. 2022, 18, 935–943, doi:10.3762/bjoc.18.93

• alanine amide (2{1})) was secured. As listed in Table 2, some of the results of the reaction optimization studies using compounds 1{1} and 2{2} followed the trends reported in Table 1. But for entries 16 and 17 in Table 2, a slow addition of the base, at −78 °C, was always used and we also checked that an

Copper-catalyzed multicomponent reactions for the efficient synthesis of diverse spirotetrahydrocarbazoles

• Shao-Cong Zhan,
• Ren-Jie Fang,
• Jing Sun and
• Chao-Guo Yan

Beilstein J. Org. Chem. 2022, 18, 796–808, doi:10.3762/bjoc.18.80

• . Synthesis of 3,3'-(arylmethylene)bis(2-methyl-1H-indole). Reaction conditions: 2-methylindole (1.0 mmol), aromatic aldehyde (0.5 mmol), CuSO4 (0.1 mmol), toluene (6.0 mL), 110 °C, 3 h. Isolated yields are shown. Proposed reaction mechanism for the multicomponent reaction. Optimization of reaction

Complementarity of solution and solid state mechanochemical reaction conditions demonstrated by 1,2-debromination of tricyclic imides

• Petar Štrbac and
• Davor Margetić

Beilstein J. Org. Chem. 2022, 18, 746–753, doi:10.3762/bjoc.18.75

• envisaged that the absence of solvent under mechanochemical conditions should prevent the formation of products from tetrahydrofuran and therefore allow cycloaddition to take place. Results and Discussion Reaction optimization Anthracene addition to dibromide 10 (Scheme 1) was used as the model reaction

Bioinspired tetraamino-bisthiourea chiral macrocycles in catalyzing decarboxylative Mannich reactions

• Hao Guo,
• Yu-Fei Ao,
• De-Xian Wang and
• Qi-Qiang Wang

Beilstein J. Org. Chem. 2022, 18, 486–496, doi:10.3762/bjoc.18.51

• and activation ability. Catalytic reaction optimization The synthesized macrocycles were then applied as catalysts in the decarboxylative addition of malonic acid half thioesters (MAHTs) to isatin-derived ketimines [48]. The reaction between ketimine 6a and MAHT 7a was initially performed in THF at

Recent advances in the syntheses of anthracene derivatives

• Giovanni S. Baviera and
• Paulo M. Donate

Beilstein J. Org. Chem. 2021, 17, 2028–2050, doi:10.3762/bjoc.17.131

• the direct synthesis of 9,10-dicyanoanthracenes from 9,10-anthraquinones [49]. Despite the challenges presented by the different substrates, a long study of reaction optimization allowed the authors to synthesize 9,10-dicyanoanthracene (70a), 2,6-dibromo- (70b), and 2,6-diiodo-9,10-dicyanoanthracene

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

• with various heterocyclic C–H acids, resulting in the synthesis of coumarin/quinolinone fused dihydropyranones and dihydropyridinones 47. The reaction optimization and the scope and limitations study were carried out using an achiral NHC, but the enantioselective version was also performed using 4

Copper-mediated oxidative C−H/N−H activations with alkynes by removable hydrazides

• Feng Xiong,
• Bo Li,
• Chenrui Yang,
• Liang Zou,
• Wenbo Ma,
• Linghui Gu,
• Ruhuai Mei and
• Lutz Ackermann

Beilstein J. Org. Chem. 2021, 17, 1591–1599, doi:10.3762/bjoc.17.113

• alkyne 2a and a stoichiometric amount of Cu(OAc)2 in DMSO (Table 1, entries 1–3). Reaction optimization revealed that the most appropriate temperature was 90 °C (Table 1, entries 3–6). An evaluation of bases showed that Na2CO3 was optimal (Table 1, entries 7–11). The best result was obtained when Cu(OAc

Metal-free glycosylation with glycosyl fluorides in liquid SO₂

• Krista Gulbe,
• Jevgeņija Lugiņina,
• Edijs Jansons,
• Artis Kinens and
• Māris Turks

Beilstein J. Org. Chem. 2021, 17, 964–976, doi:10.3762/bjoc.17.78

• ; reaction optimization data; reactivity of other glycosyl donors; proposed structures of side-products; detailed description of 19F NMR studies; stability tests for various glycosyl donors. Supporting Information File 145: Copies of NMR spectra. Supporting Information File 146: DFT calculations. Funding

Azidophosphonium salt-directed chemoselective synthesis of (E)/(Z)-cinnamyl-1H-triazoles and regiospecific access to bromomethylcoumarins from Morita–Baylis–Hillman adducts

• Soundararajan Karthikeyan,
• Radha Krishnan Shobana,
• Kamarajapurathu Raju Subimol,
• J. Helen Ratna Monica and
• Ayyanoth Karthik Krishna Kumar

Beilstein J. Org. Chem. 2020, 16, 1579–1587, doi:10.3762/bjoc.16.130

• : phosphonium salt-catalysed triazolation of MBH adducts. Scope of the one-pot cascade reaction of the unprotected Morita–Baylis–Hillman adducts 3a–q. Comparative analysis of the sequential one-pot reaction. Optimization of the triazolation of the MBH adduct 1a. Optimization of the reaction conditions for 3

Photocatalytic trifluoromethoxylation of arenes and heteroarenes in continuous-flow

• Alexander V. Nyuchev,
• Ting Wan,
• Borja Cendón,
• Carlo Sambiagio,
• Job J. C. Struijs,
• Michelle Ho,
• Moisés Gulías,
• Ying Wang and
• Timothy Noël

Beilstein J. Org. Chem. 2020, 16, 1305–1312, doi:10.3762/bjoc.16.111

• isomer is marked with a star. 19F NMR yields are reported. a CH3CN/CH2Cl2 3:2, 0.08 M; b CH3CN/CH2Cl2 1:1, 0.05 M; c CH3CN/CH2Cl2 5:3, 0.05 M; d CH3CN/CH2Cl2 3:2, 0.02 M; e CH3CN/CH2Cl2 5:4, 0.057 M. Reaction optimization under flow conditions. Influence of bases on the photoredox trifluoromethoxylation

A systematic review on silica-, carbon-, and magnetic materials-supported copper species as efficient heterogeneous nanocatalysts in “click” reactions

• Pezhman Shiri and
• Jasem Aboonajmi

Beilstein J. Org. Chem. 2020, 16, 551–586, doi:10.3762/bjoc.16.52

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

• (Scheme 30) [118]. Reaction optimization has shown Cu(OAc)2 to be suitable for this transformation whereas other Lewis acids like CuI, Cu(OTf)2 and FeCl3 gave lower yields, whereas Zn(OAc)2 did not result in any product. The strategy has well tolerated different substituents on pyridine and benzylamine as

Synthesis of 9-O-arylated berberines via copper-catalyzed C_Ar–O coupling reactions

• Qiaoqiao Teng,
• Xinhui Zhu,
• Qianqian Guo,
• Weihua Jiang,
• Jiang Liu and
• Qi Meng

Beilstein J. Org. Chem. 2019, 15, 1575–1580, doi:10.3762/bjoc.15.161

• leading to the failure of direct BBRB cross coupling. 9-O-Aryl berberine scope via cross-coupling reaction. 9-O-Ph-linked berberine dimer through double cross-coupling reaction. Optimization of the reaction conditions.a Supporting Information Supporting Information File 138: Experimental details and

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

• exceeded 15% (Table 1, entry 6). The presence of a base also plays a crucial role in the cyclization described herein, and the transformation of 3a to 4a did not occur in the presence of only the catalyst and without base (Table 1, entry 7). Finally, the reaction optimization experiments showed that the

Enantioselective phase-transfer catalyzed alkylation of 1-methyl-7-methoxy-2-tetralone: an effective route to dezocine

• Ruipeng Li,
• Zhenren Liu,
• Liang Chen,
• Jing Pan and
• Weicheng Zhou

Beilstein J. Org. Chem. 2018, 14, 1421–1427, doi:10.3762/bjoc.14.119

• inferior to the cinchonidine derivatives (C7 and C11). After a suitable catalyst (C7) was identified, further reaction optimization was performed (Table 2). In general, dichloromethane (DCM) was the common solvent for the two-phase reaction, but to our surprise, when the reaction was run in DCM (entry 2 in

Selective carboxylation of reactive benzylic C–H bonds by a hypervalent iodine(III)/inorganic bromide oxidation system

• Toshifumi Dohi,
• Shohei Ueda,
• Kosuke Iwasaki,
• Yusuke Tsunoda,
• Koji Morimoto and
• Yasuyuki Kita

Beilstein J. Org. Chem. 2018, 14, 1087–1094, doi:10.3762/bjoc.14.94

• conditions. Reaction optimization of benzylic C–H acetoxylation using PIDA. Substrate screening for benzylic C–H acetoxylation by the PIDA/NaBr system.a Supporting Information Supporting Information File 134: Starting materials and Copies of 1H and 13C NMR spectra of all products. Acknowledgements This

Bromide-assisted chemoselective Heck reaction of 3-bromoindazoles under high-speed ball-milling conditions: synthesis of axitinib

• Jingbo Yu,
• Zikun Hong,
• Xinjie Yang,
• Yu Jiang,
• Zhijiang Jiang and
• Weike Su

Beilstein J. Org. Chem. 2018, 14, 786–795, doi:10.3762/bjoc.14.66

• = 6 mm, ФMB = 0.293), 500 rpm, 45 min. Optimisation of the reaction conditions for the olefination of 3-bromoindazoles.a Examination of the influence of the grinding auxiliary on the reaction outcomea. Supporting Information Supporting Information File 108: Reaction optimization studies, details of