Catalytic trifluoromethylation of iodoarenes by use of 2-trifluoromethylated benzimidazoline as trifluoromethylating reagent

• Tatsuhiro Uchikura,
• Nanami Kamiyama,
• Taisuke Ishikawa and
• Takahiko Akiyama

Beilstein J. Org. Chem. 2020, 16, 2442–2447, doi:10.3762/bjoc.16.198

• (I)–CF3 species, generated through the reaction of benzimidazoline 2 with CuI under basic conditions, underwent an oxidative addition reaction with the aryl iodide to generate a Cu(III) complex. A subsequent reductive elimination furnished the trifluoromethylarene and Cu(I). Because an electron

Recent developments in enantioselective photocatalysis

• Callum Prentice,
• James Morrisson,
• Andrew D. Smith and
• Eli Zysman-Colman

Beilstein J. Org. Chem. 2020, 16, 2363–2441, doi:10.3762/bjoc.16.197

• synthesise the corresponding RCA products 283 in excellent yields and enantioselectivities (22 examples, up to >99:1 er) (Scheme 45) [111]. Huang et al. applied a similar catalytic system to that reported by Yoon et al. to a different radical addition reaction between nitrones 284 and aldehydes 285 (Scheme

A complementary approach to conjugated N-acyliminium formation through photoredox-catalyzed intermolecular radical addition to allenamides and allencarbamates

• Olusesan K. Koleoso,
• Matthew Turner,
• Felix Plasser and
• Marc C. Kimber

Beilstein J. Org. Chem. 2020, 16, 1983–1990, doi:10.3762/bjoc.16.165

• undergoes an addition reaction with a suitable nucleophile (Scheme 1). Importantly, the electrophilic mediated formation of this key intermediate 2 have been the cornerstone for allenamide chemistry over the past 15 years. Therefore, given the importance of the allenamide building block we sought a new

Pauson–Khand reaction of fluorinated compounds

• Jorge Escorihuela,
• Daniel M. Sedgwick,
• Alberto Llobat,
• Mercedes Medio-Simón,
• Pablo Barrio and
• Santos Fustero

Beilstein J. Org. Chem. 2020, 16, 1662–1682, doi:10.3762/bjoc.16.138

• this sense, while the addition of hard organometallic nucleophiles, such as lithium dialkylcuprates or Grignard reagents, failed, softer nucleophiles such as nitroalkanes cleanly added to the β-position, providing the Michael adduct 61. Unexpectedly, the conjugate addition reaction resulted in

The McKenna reaction – avoiding side reactions in phosphonate deprotection

• Katarzyna Justyna,
• Joanna Małolepsza,
• Damian Kusy,
• Waldemar Maniukiewicz and
• Katarzyna M. Błażewska

Beilstein J. Org. Chem. 2020, 16, 1436–1446, doi:10.3762/bjoc.16.119

• storage and/or use of BTMS, which exposes it to traces of water. As mentioned in the previous section, compounds having multiple bonds could undergo an addition reaction upon exposure to HBr [42]. We studied this problem using 1H NMR spectroscopy with the model acrylamide 11 (Scheme 3), representing a

An overview on disulfide-catalyzed and -cocatalyzed photoreactions

• Yeersen Patehebieke

Beilstein J. Org. Chem. 2020, 16, 1418–1435, doi:10.3762/bjoc.16.118

• fluorine-containing groups can effectively change the physical and chemical properties and biological activities of organic molecules [21][22]. The addition reaction using disulfide as the visible-light catalyst is an effective and atom-economic method for introducing fluorine-containing groups. In 2016

Disposable cartridge concept for the on-demand synthesis of turbo Grignards, Knochel–Hauser amides, and magnesium alkoxides

• Mateo Berton,
• Kevin Sheehan,
• Andrea Adamo and
• D. Tyler McQuade

Beilstein J. Org. Chem. 2020, 16, 1343–1356, doi:10.3762/bjoc.16.115

• possible to directly use the hygroscopic LiCl in a solid form. The back-pressure control allows a high-temperature oxidative addition reaction and enables the quantitative conversion of less reactive but more cost-effective alkyl chlorides. Furthermore, a low-cost pod-style synthesizer prototype has been

A simple and easy to perform synthetic route to functionalized thienyl bicyclo[3.2.1]octadienes

• Dragana Vuk,
• Irena Škorić,
• Valentina Milašinović,
• Krešimir Molčanov and
• Željko Marinić

Beilstein J. Org. Chem. 2020, 16, 1092–1099, doi:10.3762/bjoc.16.96

• functionalization. These functionalizations, beside the addition reaction, could involve photooxygenation reactions (Scheme 5) [1][22][23][24][25], previously studied in our laboratory. These reactions could result in a completely new spectrum of products, with preserved bicyclo[3.2.1.]octadiene skeleton, crucial

Aldehydes as powerful initiators for photochemical transformations

• Maria A. Theodoropoulou,
• Nikolaos F. Nikitas and
• Christoforos G. Kokotos

Beilstein J. Org. Chem. 2020, 16, 833–857, doi:10.3762/bjoc.16.76

• of the benzophenone 172 to the triplet state 173 by UV irradiation, followed by HAT from the aldehyde 170 to 173 and the formation of the acyl radical 175. At the same time, the nickel(0) complex 176 performs an oxidative addition reaction to the aryl bromide 171, and the nickel(II) complex 177

Synthesis of C₇₀-fragment buckybowls bearing alkoxy substituents

• Yumi Yakiyama,
• Shota Hishikawa and
• Hidehiro Sakurai

Beilstein J. Org. Chem. 2020, 16, 681–690, doi:10.3762/bjoc.16.66

• the preparative TLC (PTLC) purification was conducted using Wakogel B-5F PTLC plates. Elemental analyses were measured on a J-Science Micro corder JM10 at the Analysis Center at Osaka University. General experimental procedure for the addition reaction In a similar manner as described in [18], to a

Regio- and stereoselective synthesis of new ensembles of diversely functionalized 1,3-thiaselenol-2-ylmethyl selenides by a double rearrangement reaction

• Svetlana V. Amosova,
• Andrey A. Filippov,
• Nataliya A. Makhaeva,
• Alexander I. Albanov and
• Vladimir A. Potapov

Beilstein J. Org. Chem. 2020, 16, 515–523, doi:10.3762/bjoc.16.47

• -ylmethylselanyl heterocycles connected by a carbon bridge was demonstrated (e.g., compound 6k containing two 1,3-thiaselenol-2-ylmethylselanyl heterocycles connected by a six-carbon bridge). The 1,3-thiaselenol-2-ylmethylselenolate anion generated from selenocyanate 4 was also subjected to a nucleophilic addition

• reaction with activated acetylenes (Scheme 9). The reaction of the 1,3-thiaselenol-2-ylmethylselenolate anion with alkyl propiolates proceeded in a regio- and stereoselective manner affording alkyl 3-[(1,3-thiaselenol-2-ylmethyl)selanyl]-2-propenoates 7a (Z/E = 94:6) and 7b (Z/E = 93:7) in 94% and 90

Controlling alkyne reactivity by means of a copper-catalyzed radical reaction system for the synthesis of functionalized quaternary carbons

• Goki Hirata,
• Yu Yamane,
• Naoya Tsubaki,
• Reina Hara and
• Takashi Nishikata

Beilstein J. Org. Chem. 2020, 16, 502–508, doi:10.3762/bjoc.16.45

• alkene derivatives. Because an alkyne undergoes addition reaction at a C–C triple bond or cross-coupling at a terminal C–H bond. Combining those reaction patterns could realize a new reaction methodology to synthesize complex molecules including C–C multiple bonds. In this report, we found that the

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

• conjugated to a cystein residue of serum albumin via a Michael addition reaction. At the same time, it is well known that 5,10,15,20-tetrakis(pentafluorophenyl)porphyrin and its chlorin derivatives generate singlet oxygen by the light irradiation under atmospheric oxygen [31]. These tetrapyrrole macrocycles

Synthesis and biological evaluation of truncated derivatives of abyssomicin C as antibacterial agents

• Leticia Monjas,
• Peter Fodran,
• Johanna Kollback,
• Carlo Cassani,
• Thomas Olsson,
• Maja Genheden,
• D. G. Joakim Larsson and
• Carl-Johan Wallentin

Beilstein J. Org. Chem. 2019, 15, 1468–1474, doi:10.3762/bjoc.15.147

• carbonyl addition reaction between aldehyde 3 and the tetronate derivatives 4 and 5, followed by a ring-closing metathesis (Scheme 1). Since both enantiomers of AbC have similar activity [25], we pursued racemic synthesis of the targeted compounds. We synthesized the common building block 3 in six steps

Ugi reaction-derived prolyl peptide catalysts grafted on the renewable polymer polyfurfuryl alcohol for applications in heterogeneous enamine catalysis

• Alexander F. de la Torre,
• Gabriel S. Scatena,
• Oscar Valdés,
• Daniel G. Rivera and
• Márcio W. Paixão

Beilstein J. Org. Chem. 2019, 15, 1210–1216, doi:10.3762/bjoc.15.118

• employ a three-component, diastereoselective variant of the Ugi reaction for the synthesis of a prolyl pseudo-peptide catalyst, which proved effective in an organocatalytic conjugate addition reaction [6]. Later, our groups developed an Ugi reaction-based multicomponent approach enabling the structure

Electrophilic oligodeoxynucleotide synthesis using dM-Dmoc for amino protection

• Shahien Shahsavari,
• Dhananjani N. A. M. Eriyagama,
• Bhaskar Halami,
• Vagarshak Begoyan,
• Marina Tanasova,
• Jinsen Chen and
• Shiyue Fang

Beilstein J. Org. Chem. 2019, 15, 1116–1128, doi:10.3762/bjoc.15.108

• the nucleophiles on ODNs including hydroxy and amino groups. Even the reaction took place, a hindered four-substituted carbon center would be formed. Because the Michael addition reaction is reversible, the adducts would easily fall apart to give back un-modified ODNs. Indeed, due to the use of dM

An anomalous addition of chlorosulfonyl isocyanate to a carbonyl group: the synthesis of ((3aS,7aR,E)-2-ethyl-3-oxo-2,3,3a,4,7,7a-hexahydro-1H-isoindol-1-ylidene)sulfamoyl chloride

• Aytekin Köse,
• Aslı Ünal,
• Ertan Şahin,
• Uğur Bozkaya and
• Yunus Kara

Beilstein J. Org. Chem. 2019, 15, 931–936, doi:10.3762/bjoc.15.89

• study, we developed a new addition reaction of chlorosulfonyl isocyanate (CSI), starting from 2-ethyl-3a,4,7,7a-tetrahydro-1H-isoindole-1,3(2H)-dione. The addition reaction of CSI with 2-ethyl-3a,4,7,7a-tetrahydro-1H-isoindole-1,3(2H)-dione resulted in the formation of ylidenesulfamoyl chloride, whose

• exact configuration was determined by X-ray crystal analysis. We explain the mechanism of product formation supported by theoretical calculations. Keywords: addition reaction; chlorosulfonyl isocyanate; sulfamoyl chloride; theoretical calculations; Introduction Since its identification in 1959 [1

• mechanism of the addition product. Such an addition reaction is one of the unique examples that define the addition of CSI. Furthermore, the chemical transformation of chlorosulfonyl isocyanate to the related compounds is currently under investigation. Experimental General All reagents and substrates were

Diastereo- and enantioselective preparation of cyclopropanol derivatives

• Marwan Simaan and
• Ilan Marek

Beilstein J. Org. Chem. 2019, 15, 752–760, doi:10.3762/bjoc.15.71

• ). First, we checked that the carbometalation reaction was regio- and diastereoselective by addition of lower order cyanocuprate, easily obtained from the corresponding organolithium and a stoichiometric amount of CuCN (Scheme 4) [68][69][70]. The addition reaction proceeds similarly for the addition of

The LANCA three-component reaction to highly substituted β-ketoenamides – versatile intermediates for the synthesis of functionalized pyridine, pyrimidine, oxazole and quinoxaline derivatives

• Tilman Lechel,
• Roopender Kumar,
• Mrinal K. Bera,
• Reinhold Zimmer and
• Hans-Ulrich Reissig

Beilstein J. Org. Chem. 2019, 15, 655–678, doi:10.3762/bjoc.15.61

• the solvent methanol to the double bond provided compound PO27 as major product (Scheme 17) [32]. It was not studied whether the use of other solvents can suppress this addition reaction. The allyl-substituted β-ketoenamide KE7 was converted under the standard conditions into condensation product PO28

Nucleofugal behavior of a β-shielded α-cyanovinyl carbanion

• Rudolf Knorr and
• Barbara Schmidt

Beilstein J. Org. Chem. 2018, 14, 3018–3024, doi:10.3762/bjoc.14.281

• and a carbonyl compound (R1)2C=O. Such a C–C fission (retro-addition reaction) can occur already near room temperature (rt) if the nucleofugal carbanion proves to be an electronically stabilized N≡C–CH2– [1] or allylic [2] species or a short-lived equilibrium component [3]. A cleavable alkoxide A1M1

• “normal” C=O addition reaction was obviously faster than the deprotonation of 19 and also apparently irreversible under the reaction conditions, whereas the unobserved C=O addition of 19 to 2Li might be possible yet quickly reversible with a terminating proton transfer from 19 to 2Li as shown in Scheme 5

• blocked by FSiMe3 and hence unsuitable for an analysis of the retro-addition reaction (see Supporting Information File 1). Conclusion (i) The nucleofugal carbanion (α-deprotonated 1) can escape with surprising ease from alkoxides, perhaps with some assistance by a metal cation if present. Conversely

Molecular iodine-catalyzed one-pot multicomponent synthesis of 5-amino-4-(arylselanyl)-1H-pyrazoles

• Camila S. Pires,
• Daniela H. de Oliveira,
• Maria R. B. Pontel,
• Jean C. Kazmierczak,
• Roberta Cargnelutti,
• Diego Alves,
• Raquel G. Jacob and
• Ricardo F. Schumacher

Beilstein J. Org. Chem. 2018, 14, 2789–2798, doi:10.3762/bjoc.14.256

• could be obtained in 90% yield as depicted in Scheme 3. On the basis of previous reports [21][25] a mechanism can be proposed for this reaction as depicted in Scheme 4. Initially, we believe that arylhydrazine 2 reacts with benzoylacetonitrile 1 by a 1,2-addition reaction in the presence of iodine as

Unprecedented nucleophile-promoted 1,7-S or Se shift reactions under Pummerer reaction conditions of 4-alkenyl-3-sulfinylmethylpyrroles

• Takashi Go,
• Akane Morimatsu,
• Hiroaki Wasada,
• Genzoh Tanabe,
• Osamu Muraoka,
• Yoshiharu Sawada and
• Mitsuhiro Yoshimatsu

Beilstein J. Org. Chem. 2018, 14, 2722–2729, doi:10.3762/bjoc.14.250

• TFAA to form sulfonium salt 14, which is characterised by an intramolecular double bond [34][35]. A less substituted double bond easily approaches the sulfonium ion and undergoes an addition reaction to produce intermediate 15. The trifluoroacetate anion attacks the posterior side of the α-carbon of

Learning from B₁₂ enzymes: biomimetic and bioinspired catalysts for eco-friendly organic synthesis

• Keishiro Tahara,
• Ling Pan,
• Toshikazu Ono and
• Yoshio Hisaeda

Beilstein J. Org. Chem. 2018, 14, 2553–2567, doi:10.3762/bjoc.14.232

• reported by many researchers [67][68][69]. 3-1. Methyl transfer to thiols Chemical reductants such as NaBH4 or electrochemical reduction could provide Co(I) species, so that α-methylated and β-methylated B12 could be formed by the oxidative addition reaction with a methyl donor. The supernucleophile Co(I

Stereoselective total synthesis and structural revision of the diacetylenic diol natural products strongylodiols H and I

• Pamarthi Gangadhar,
• Sayini Ramakrishna,
• Ponneri Venkateswarlu and
• Pabbaraja Srihari

Beilstein J. Org. Chem. 2018, 14, 2313–2320, doi:10.3762/bjoc.14.206

• -selective reduction [25] of alkyne 20 was easily achieved with sodium bis(2-methoxyethoxy)aluminum hydride (Red-Al) as a hydride-transfer reagent to furnish the corresponding (E)-allylic alcohol 23. A Swern oxidation of 23 provided the corresponding aldehyde which was subjected to an addition reaction with

Hydroarylations by cobalt-catalyzed C–H activation

• Rajagopal Santhoshkumar and
• Chien-Hong Cheng

Beilstein J. Org. Chem. 2018, 14, 2266–2288, doi:10.3762/bjoc.14.202

• in cobalt-catalyzed C–H functionalizations. In this context, Li and co-workers developed an addition reaction of indoles 7 with activated alkenes using a cobalt(III) catalyst (Scheme 27) [79]. The reaction tolerated a wide range of alkenes including vinyl aldehyde, ketones, and divinyl ketones and a

• -catalyzed hydroarylation of C=X bonds Transition-metal-catalyzed addition of C–H bond to polar π bonds such as imines, isocyanates and carbonyls is one of the efficient methods to incorporate heteroatoms in organic molecules [45]. Yoshikai et al. developed an addition reaction of arylpyridines 3 to imines