A selective removal of the secondary hydroxy group from ortho-dithioacetal-substituted diarylmethanols

• Anna Czarnecka,
• Emilia Kowalska,
• Agnieszka Bodzioch,
• Joanna Skalik,
• Marek Koprowski,
• Krzysztof Owsianik and
• Piotr Bałczewski

Beilstein J. Org. Chem. 2018, 14, 1229–1237, doi:10.3762/bjoc.14.105

• bond and consequently the reduction of the former should a priori occur preferentially [53][54][55]. According to the best of our knowledge, there are no literature reports concerning selective reductions of dibenzylic hydroxy groups in the presence of ortho-acetal or ortho-thioacetal functions. Such

• reductions may give an access to new series of ortho-formyl-protected diarylmethanes as well as their formyl-modified derivatives, obtained after deprotection of the 1,3-dithianyl group with one of the available methods [56]. Herein, we present the first example of a selective and efficient reduction of

Mechanochemistry of nucleosides, nucleotides and related materials

• Olga Eguaogie,
• Joseph S. Vyle,
• Patrick F. Conlon,
• Manuela A. Gîlea and
• Yipei Liang

Beilstein J. Org. Chem. 2018, 14, 955–970, doi:10.3762/bjoc.14.81

• arduous ion-exchange and drying processes required to render these materials soluble in organic solvents. Likewise, significant reductions in solvent processing (especially if these are high boiling and often toxic and/or carcinogenic) is an attractive green chemistry target. In this context, Thorwith et

High-yielding continuous-flow synthesis of antimalarial drug hydroxychloroquine

• Eric Yu,
• Hari P. R. Mangunuru,
• Nakul S. Telang,
• Caleb J. Kong,
• Jenson Verghese,
• Stanley E. Gilliland III,
• Saeed Ahmad,
• Raymond N. Dominey and
• B. Frank Gupton

Beilstein J. Org. Chem. 2018, 14, 583–592, doi:10.3762/bjoc.14.45

• to limited solubility of ammonia in THF. H2/Raney-nickel reductions are often carried out in alcoholic media where much higher concentrations of ammonia are achievable but would require a solvent exchange. There are many reports of continuous-flow chemistry methods for reductive amination of ketones

Addition of dithi(ol)anylium tetrafluoroborates to α,β-unsaturated ketones

• Yu-Chieh Huang,
• An Nguyen,
• Simone Gräßle,
• Sylvia Vanderheiden,
• Nicole Jung and
• Stefan Bräse

Beilstein J. Org. Chem. 2018, 14, 515–522, doi:10.3762/bjoc.14.37

• demonstrated by examples including the use of additional electrophiles (13a, 13b) or nucleophiles (9i, 9j), the use of a chiral auxiliary (15) or reductions of the obtained products 4 (16a, 16b). aCH2Cl2, 1 equiv Me2AlCl, rt; 13a: 1 h, 13b: 18 h. bdr was calculated from the 1H NMR results. Synthesis of diene

Conformational preferences of α-fluoroketones may influence their reactivity

• Graham Pattison

Beilstein J. Org. Chem. 2017, 13, 2915–2921, doi:10.3762/bjoc.13.284

• atoms on the reactivity. The reactivity of α-fluoroacetophenone was compared to α-chloro- and α-bromoacetophenone in sodium borohydride reductions, using 0.2 equiv of NaBH4 to 1.0 equiv of α-fluoroacetophenone and 1.0 equiv of the second α-haloacetophenone to ensure the reaction stopped at low

Homologated amino acids with three vicinal fluorines positioned along the backbone: development of a stereoselective synthesis

• Raju Cheerlavancha,
• Ahmed Ahmed,
• Yun Cheuk Leung,
• Aggie Lawer,
• Qing-Quan Liu,
• Marina Cagnes,
• Hee-Chan Jang,
• Xiang-Guo Hu and
• Luke Hunter

Beilstein J. Org. Chem. 2017, 13, 2316–2325, doi:10.3762/bjoc.13.228

• reductions to arylamines were successful, an alternative approach was investigated in which the nitroarene group would be converted into the corresponding acetanilide 43. If this approach were successful, it was envisaged that the acetanilide 43 could be directly oxidised to carboxylic acid 44, thereby

Synthesis of benzannelated sultams by intramolecular Pd-catalyzed arylation of tertiary sulfonamides

• Valentin A. Rassadin,
• Mirko Scholz,
• Anastasiia A. Klochkova,
• Armin de Meijere and
• Victor V. Sokolov

Beilstein J. Org. Chem. 2017, 13, 1932–1939, doi:10.3762/bjoc.13.187

• , sultams have been prepared employing Diels–Alder reactions, radical cyclizations, reductions of sulfonylimines, ring-closing metatheses, nucleophilic aromatic substitutions and Heck cyclizations [14][15][16]. Earlier on, our group has developed versatile syntheses of sultams based on the transformation of

Total synthesis of elansolids B1 and B2

• Liang-Liang Wang and
• Andreas Kirschning

Beilstein J. Org. Chem. 2017, 13, 1280–1287, doi:10.3762/bjoc.13.124

• first synthesis of elansolid B2 (3). The key for improvement was to abandon the two Sonogashira reactions along with the syn-reductions of the two alkynes. Instead, we planned to utilize the Suzuki–Miyaura and the Stille reactions and two Z-configured vinyl iodides to assemble the (Z,E,Z)-triene unit

Synthesis of alkynyl-substituted camphor derivatives and their use in the preparation of paclitaxel-related compounds

• M. Fernanda N. N. Carvalho,
• Rudolf Herrmann and
• Gabriele Wagner

Beilstein J. Org. Chem. 2017, 13, 1230–1238, doi:10.3762/bjoc.13.122

• group and the sulfonylimine. One way to achieve this could be in the chemoselective reduction of the C=N group of oxoimide 3, addition of the alkynyl moiety to the carbonyl group, and re-oxidation of the sultam to the sulfonimide (see Scheme 4). There are a number of reductions of oxoimide 3 reported in

The reductive decyanation reaction: an overview and recent developments

• Jean-Marc R. Mattalia

Beilstein J. Org. Chem. 2017, 13, 267–284, doi:10.3762/bjoc.13.30

• reduction of radical probes (no rearranged products formed from 25d,l,m) and deuterium-labelling experiments (no deuterium incorporation using THF-d8 and quenching with D2O) discard the possibility of a single-electron transfer pathway. Other reductions suggest a hydride addition with formation of an iminyl

A versatile route to polythiophenes with functional pendant groups using alkyne chemistry

• Xiao Huang,
• Li Yang,
• Rikard Emanuelsson,
• Jonas Bergquist,
• Maria Strømme,
• Martin Sjödin and
• Adolf Gogoll

Beilstein J. Org. Chem. 2016, 12, 2682–2688, doi:10.3762/bjoc.12.265

• both EDOT-based oxidation and MV-centered reductions. The build-up of the MV-centered redox peaks is clearly evident at −0.8 V vs Fc+/Fc0 and −1.2 V vs Fc+/Fc0 corresponding to the MV2+/+ redox reaction and the MV+/0 redox reaction, respectively. The CVs of these polymers can be found in Supporting

Interactions between cyclodextrins and cellular components: Towards greener medical applications?

• Loïc Leclercq

Beilstein J. Org. Chem. 2016, 12, 2644–2662, doi:10.3762/bjoc.12.261

Useful access to enantiomerically pure protected inositols from carbohydrates: the aldohexos-5-uloses route

• Felicia D’Andrea,
• Giorgio Catelani,
• Lorenzo Guazzelli and
• Venerando Pistarà

Beilstein J. Org. Chem. 2016, 12, 2343–2350, doi:10.3762/bjoc.12.227

• stereoseries, allowed for the rationalisation of a mechanism of the reaction based on open-transition-state models and electron-withdrawing inductive effects. Complementary reductions of the intermediate inososes were possible by changing the reaction conditions, and two isomeric inositol derivatives were

• structure of every inosose obtained allows for complementary stereoselective reductions by choosing the proper reaction conditions. In fact (Table 1), the substituents α to the keto function (2 and 6) and the axial OH in position 3 have always a cis orientation which would favour an equatorially directed

• ] (condition B). The axial OH function would be able to coordinate the reducing agent and thus give an internal hydride transfer from the same side through a six membered cyclic transition state (Figure 3). In Table 2, the results of the complementary reductions (conditions A and B) are summarised (see

Robust C–C bonded porous networks with chemically designed functionalities for improved CO₂ capture from flue gas

• Damien Thirion,
• Joo S. Lee,
• Ercan Özdemir and
• Cafer T. Yavuz

Beilstein J. Org. Chem. 2016, 12, 2274–2279, doi:10.3762/bjoc.12.220

• different routes, either by reduction to the corresponding amine or reaction with hydroxylamine into an amidoxime. For the reduction, three reagents (LiAlH4, BH3–THF and BH3–Me2S) were screened. All reductions were chemically successful, but the textural properties of the modified networks were noticeably

Synthesis and characterization of fluorinated azadipyrromethene complexes as acceptors for organic photovoltaics

• Forrest S. Etheridge,
• Roshan J. Fernando,
• Sandra Pejić,
• Matthias Zeller and
• Geneviève Sauvé

Beilstein J. Org. Chem. 2016, 12, 1925–1938, doi:10.3762/bjoc.12.182

• cases of Zn(L1)2 and Zn(L4)2, fluorine has a similar stabilizing effect on both the cation and anion. The differences between the first and second reduction potentials of each compound were similar, indicating that fluorine influences both reductions equally. For the fluorinated BF2+ complexes, the

Practical synthetic strategies towards lipophilic 6-iodotetrahydroquinolines and -dihydroquinolines

• David R. Chisholm,
• Garr-Layy Zhou,
• Ehmke Pohl,
• Roy Valentine and
• Andrew Whiting

Beilstein J. Org. Chem. 2016, 12, 1851–1862, doi:10.3762/bjoc.12.174

• corresponding 1,4-DHQ of scaffold 1 has not been synthesised to our knowledge. Similar DHQs are typically prepared by methods such as ring-closing metathesis, or by controlled Birch-type reductions of the corresponding quinoline [10][11][12]. Very few instances of iodine-containing THQs or DHQs exist in the

• addition of DIBAL to 20a.a DIBAL reductions of quinolin-2-ones 23a–e using the optimised method to synthesise 22.a Comparing the reactivity of 6-iodo-THQ 21 and 6-bromo-THQ 26 in a typical Suzuki reaction with boronic ester 27 to give biaryl 28. Supporting Information Supporting information features full

Enabling technologies and green processes in cyclodextrin chemistry

• Giancarlo Cravotto,
• Marina Caporaso,
• Laszlo Jicsinszky and
• Katia Martina

Beilstein J. Org. Chem. 2016, 12, 278–294, doi:10.3762/bjoc.12.30

• friendly technique that is well suited to the selective chemical modification of CDs from native α-, β- and γ-CD. The use of this method in heterogeneous phase reactions, such as reductions and “click reactions” [14], is well known, as is its use in full CD derivatization in combination with MW irradiation

Biocatalysis for the application of CO₂ as a chemical feedstock

• Apostolos Alissandratos and
• Christopher J. Easton

Beilstein J. Org. Chem. 2015, 11, 2370–2387, doi:10.3762/bjoc.11.259

• converted into a wide range of fuels and commodity chemicals, through the multitude of known enzymatic reactions. The required reducing equivalents for the net carbon reductions may be drawn from solar energy, electricity or chemical oxidation, and delivered in vitro or through cellular mechanisms, while

Effective ascorbate-free and photolatent click reactions in water using a photoreducible copper(II)-ethylenediamine precatalyst

• Redouane Beniazza,
• Natalia Bayo,
• Florian Molton,
• Carole Duboc,
• Stéphane Massip,
• Nathan McClenaghan,
• Dominique Lastécouères and
• Jean-Marc Vincent

Beilstein J. Org. Chem. 2015, 11, 1950–1959, doi:10.3762/bjoc.11.211

• experiments were carried out in quartz cuvettes to follow the disappearance of the low-energy visible light absorption band (550–600 nm) ascribed to a d–d electronic transition, which is typical for CuII complexes (d9). The reductions were typically conducted under strictly anaerobic conditions, deaeration of

• the water-soluble alkynes 5, 6 or 7 were added (50 equiv with respect to Cu) and the aqueous solution irradiated, a decrease of the intensity of the EPR signal was observed, in agreement with a reduction process (Figure 3c–e). In the presence of propargyl alcohol 5 or propargyl ether 6 the reductions

Fates of imine intermediates in radical cyclizations of N-sulfonylindoles and ene-sulfonamides

• Hanmo Zhang,
• E. Ben Hay,
• Stephen J. Geib and
• Dennis P. Curran

Beilstein J. Org. Chem. 2015, 11, 1649–1655, doi:10.3762/bjoc.11.181

• radical 17 that may be too stable to rapidly abstract a hydrogen atom from tin hydride (Figure 3b). Thus, imine 11 survives to isolation. That said, we cannot rule out ionic (hydride-type) reduction of imine 14 by tin hydride. Simple imines are not easily reduced by Bu3SnH alone, but ionic reductions can

The facile construction of the phthalazin-1(2H)-one scaffold via copper-mediated C–H(sp²)/C–H(sp) coupling under mild conditions

• Wei Zhu,
• Bao Wang,
• Shengbin Zhou and
• Hong Liu

Beilstein J. Org. Chem. 2015, 11, 1624–1631, doi:10.3762/bjoc.11.177

• to dramatic reductions in yields (Table 1, entries 16 and 17). Gratifyingly, the temperature screening showed that the transformation yield was further enhanced by reducing the reaction temperature to 80 °C (Table 1, entry 18). The reaction could also be conducted under the atmosphere of air (Table 1

Star-shaped tetrathiafulvalene oligomers towards the construction of conducting supramolecular assembly

• Masahiko Iyoda and
• Masashi Hasegawa

Beilstein J. Org. Chem. 2015, 11, 1596–1613, doi:10.3762/bjoc.11.175

• the color at −70 °C is purple. On the other hand, as shown in Figure 11, a solution of 33 exhibits deep green in CS2 but purple in CH2Cl2 [69]. CV analysis of 28–34 in solution showed different behaviors (Table 4). The [12]annulenes 28, 29, and 33 exhibited two reversible one-electron reductions due

• oxidation potential splited in two with the strong intermolecular interaction in 31•+. TTF-functionalized radiaannulenes (RAs) 34 and 35 also exhibit multiple redox states [70]. CV analysis of 34 shows the two reversible one-electron reductions as the reduction of the RA core, whereas the three reversible

Preparative semiconductor photoredox catalysis: An emerging theme in organic synthesis

• David W. Manley and
• John C. Walton

Beilstein J. Org. Chem. 2015, 11, 1570–1582, doi:10.3762/bjoc.11.173

• components, decarboxylative arylations of amino acids, diastereoselective preparations of cis-cyclobutanes via [2 + 2] cycloadditions of enones, selective reductions of benzylic and α-carbonyl halides and, with fac-Ir(ppy)3, reductions of unactivated alkyl iodides [5][6][7][8]. Furthermore, the value of

• reductions and protonations. The ROS generated in these ways oxidize any organic components or pollutants, by well-known oxidation and autoxidation processes, eventually leading to complete mineralization with production of CO2, water and mineral acids. Research in this area has been extensive [17] and as a

• transformations an excess of a sacrificial electron donor (reductive quencher) is needed to scavenge the VB holes and prevent e−/h+ recombination. Alcohols and amines have been successfully deployed in this role. Reductions of nitroaromatics took place effectively in photoactivated aqueous TiO2 slurries, with

Reactions of nitroxides 15. Cinnamates bearing a nitroxyl moiety synthesized using a Mizoroki–Heck cross-coupling reaction

• Jerzy Zakrzewski and
• Bogumiła Huras

Beilstein J. Org. Chem. 2015, 11, 1155–1162, doi:10.3762/bjoc.11.130

• recognized (e.g., reductions, acidic medium, carbene addition, etc.). Because we would like to check the possibility of performing the Mizoroki–Heck cross-coupling reaction with nitroxides, herein the synthesis of cinnamates bearing a nitroxyl moiety is presented using aryl iodides as exemplary test

Interactions between tetrathiafulvalene units in dimeric structures – the influence of cyclic cores

• Huixin Jiang,
• Virginia Mazzanti,
• Christian R. Parker,
• Søren Lindbæk Broman,
• Jens Heide Wallberg,
• Karol Lušpai,
• Adam Brincko,
• Henrik G. Kjaergaard,
• Anders Kadziola,
• Peter Rapta,
• Ole Hammerich and
• Mogens Brøndsted Nielsen

Beilstein J. Org. Chem. 2015, 11, 930–948, doi:10.3762/bjoc.11.104

• radiaannulene 8 underwent reversible reductions at −1.12 V and −1.51 V. The readiness of the first reduction may again be explained by the generation of a 14 πz aromatic core of the radical anion as shown in Figure 7. Thus, again the first reduction occurred at much less negative potential than that of its

• an intramolecular origin of the NIR absorptions. Finally, the different radiaannulene cores also present redox-active units, undergoing reversible and ready reductions, which we ascribe to some gain in aromaticity upon reduction. On account of these electron-accepting properties, the neutral TTF