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

• light yellow oil by chromatography with a yield of 64%. The yield of the transetherification product was influenced by two factors. Substrate concentrations below 0.5 M resulted in much less polymerization, leaving more diols for transetherification. However, still lower concentrations of less than 0.1

• % could be obtained, but this would not be sufficient for large scale production, besides considering the environmental impact of requiring a halogenated solvent. Comparing the structural difference between diols 2 and 7, these results emphasized that the isolation of the alkyne from the ethylenediol by

Formose reaction controlled by boronic acid compounds

• Toru Imai,
• Tomohiro Michitaka and
• Akihito Hashidzume

Beilstein J. Org. Chem. 2016, 12, 2668–2672, doi:10.3762/bjoc.12.263

• optimizing the conditions of the formose reaction [6][7][8][9][10][11][12][13][14][15]. However, the selective formose reaction is still an important subject of investigation [16]. It is known that boronic acid compounds form esters with diols, e.g., sugars [17][18]. Boronic acid compounds may thus stabilize

Synthesis of polyhydroxylated decalins via two consecutive one-pot reactions: 1,4-addition/aldol reaction followed by RCM/syn-dihydroxylation

• Michał Malik and
• Sławomir Jarosz

Beilstein J. Org. Chem. 2016, 12, 2602–2608, doi:10.3762/bjoc.12.255

• ]. After desilylation followed by protection of the free hydroxy with a benzoyl group and deprotection of the isopropylidene moiety, diols 20 and 24 were obtained. With α,β-unsaturated ketones 17 and 18 and two enantiomeric, optically pure aldehydes (R)- and (S)-10 in hand, we started to study the 1,4

• the subsequent syn-dihydroxylation with NaIO4 as a stoichiometric oxidant in the presence of catalytic amounts of CeCl3 (15 mol %). As a result, in the case of diolefin 25 as substrate, a separable mixture of diols (dr = 8:1; 27 being the major isomer) was obtained in fair yield (56%). The same

Isosorbide and dimethyl carbonate: a green match

• Fabio Aricò and
• Pietro Tundo

Beilstein J. Org. Chem. 2016, 12, 2256–2266, doi:10.3762/bjoc.12.218

• isosorbide was almost quantitative (95.2%). Similarly poly(aliphaticdiol-co-isosorbide carbonate)s were prepared via melt polycondensation of DMC with isosorbide and several aliphatic diols employing Li(acac) and the TiO2/SiO2-based catalyst (Scheme 4) [85]. High-molecular-weight (Mw = 32,600) and optically

The direct oxidative diene cyclization and related reactions in natural product synthesis

• Juliane Adrian,
• Leona J. Gross and
• Christian B. W. Stark

Beilstein J. Org. Chem. 2016, 12, 2104–2123, doi:10.3762/bjoc.12.200

• prepared from commercially available neryl acetate (15). The auxiliary-controlled, permanganate-promoted oxidation of diene 16 proceeded selectively at low temperatures, affording the corresponding diastereomeric THF diols as an inseparable mixture (dr 7:1, major stereoisomer shown in Scheme 6). Compound

• [84]. Thus, the corresponding THF diols were obtained in 55% yield. In addition to the desired THF diol 28a for the total synthesis of cis-solamin A (29), small amounts of its diastereoisomer 28b were isolated (dr 10:1, Scheme 8 left). Similar permanganate-mediated oxidative cyclizations were also

• [92][97]. In this case, two permanganate-promoted type A oxidative cyclization reactions were used to establish the two THF rings of this acetogenin (Scheme 11). Both THF diols 43 and 47 were isolated as pure diastereoisomers with high diastereocontrol (dr 9:1 for 43 and dr 8.7:1 for 47, respectively

Ionic liquids as transesterification catalysts: applications for the synthesis of linear and cyclic organic carbonates

• Maurizio Selva,
• Alvise Perosa,
• Sandro Guidi and
• Lisa Cattelan

Beilstein J. Org. Chem. 2016, 12, 1911–1924, doi:10.3762/bjoc.12.181

• should therefore implement greener reactions, such as the direct carboxylation of diols by CO2, for which however, effective catalysts are currently not available. The Asahi Kasei process also highlights that the synthesis of DMC by transesterification of ethylene carbonate with methanol does not

• synthesize organic carbonates consists in the acid or base-catalyzed transesterification of dimethyl carbonate (DMC), the simplest organic carbonate, with alcohols R–OH or diols to yield either acyclic organic carbonates or cyclic carbonates, respectively (Scheme 8). A literature survey on the synthesis of

• diols can be carried out in the presence of basic (e.g., tertiary phosphines and amines, alkali metal hydroxides, alkoxides, halides, carbonates, alkali metal exchanged faujasites and hydrotalcites) or acidic catalysts or co-catalysts, and under thermal (non-catalytic) conditions. All applicable

Rearrangements of organic peroxides and related processes

• Ivan A. Yaremenko,
• Vera A. Vil’,
• Dmitry V. Demchuk and
• Alexander O. Terent’ev

Beilstein J. Org. Chem. 2016, 12, 1647–1748, doi:10.3762/bjoc.12.162

• treatment of unsubstituted bicyclic endoperoxides 229 by bases affords 4-hydroxyenones 230 [344] which are useful precursors in asymmetric organic syntheses. Alternative synthetic methods towards this class of compounds normally require a metal-catalyzed or biocatalyzed oxidation of diols 231 in an

Efficient syntheses of climate relevant isoprene nitrates and (1R,5S)-(−)-myrtenol nitrate

• Sean P. Bew,
• Glyn D. Hiatt-Gipson,
• Graham P. Mills and
• Claire E. Reeves

Beilstein J. Org. Chem. 2016, 12, 1081–1095, doi:10.3762/bjoc.12.103

• application to the synthesis of high-boiling diols is more difficult due to their low-vapour pressures. Recently Cohen et al. synthesised mixtures of IPNs via the reaction of (±)-isoprene epoxide with pre-ground bismuth(III) nitrate [19]. Using a preliminary ’flash’ purification (silica gel) afforded an

• the diols or execute a regioselective 1° or 2° mono-O-nitration was not. Eliminating the former problem Hodgson et al. [26] reported rac-17 could be generated from cheap, commercially available 2,5-dihydrofuran which, after epoxidation with meta-chloroperbenzoic acid (mCPBA), afforded epoxide 21 in a

Catalytic asymmetric synthesis of biologically important 3-hydroxyoxindoles: an update

• Bin Yu,
• Hui Xing,
• De-Quan Yu and
• Hong-Min Liu

Beilstein J. Org. Chem. 2016, 12, 1000–1039, doi:10.3762/bjoc.12.98

• asymmetric aldol reaction of trifluoromethyl α-fluorinated β-keto gem-diols with isatins, generating 3-hydroxyoxindoles in high yields (up to 99%) and with excellent enantioselectivities (up to 98% ee, Scheme 28) [45]. The reaction was performed at room temperature using AcOH as the additive in the presence

• of 10% of catalyst loading. Interestingly, the protocol employed gem-diols as equivalents of fluorinated aryl/alkyl methyl ketone enolates for the C–C bond formation accompanied the release of trifluoroacetate. This method showed a broad substrate scope including gem-diols with phenyl rings

• , heterocyclic groups and aliphatic groups. A plausible mechanism was proposed as shown in Scheme 29. The thiourea NH moieties and the tertiary amino group of the catalyst activated the carbonyl groups of isatin and the α-protons of gem-diols, respectively through hydrogen bond interactions. The α-proton of gem

One-pot synthesis of enantiomerically pure N-protected allylic amines from N-protected α-amino esters

• Gastón Silveira-Dorta,
• Sergio J. Álvarez-Méndez,
• Víctor S. Martín and
• José M. Padrón

Beilstein J. Org. Chem. 2016, 12, 957–962, doi:10.3762/bjoc.12.94

• . Disappointingly, the product (E)-4a was obtained in low yield although in excellent (dia)stereoselectivity. In the synthesis of anti-2-amino-1,3-diols, we reported earlier that the addition of DIBAL-H must be done necessarily in two portions [16]. Thus, fine-tuning of the reduction conditions was required in

Scope and mechanism of the highly stereoselective metal-mediated domino aldol reactions of enolates with aldehydes

• M. Emin Cinar,
• Bernward Engelen,
• Martin Panthöfer,
• Hans-Jörg Deiseroth,
• Jens Schlirf and
• Michael Schmittel

Beilstein J. Org. Chem. 2016, 12, 813–824, doi:10.3762/bjoc.12.80

• aldehydes in the presence of metal halides to furnish tetrahydro-2H-pyran-2,4-diols in a highly diastereoselective manner, is investigated thoroughly by experiments and computations. The reaction was also successfully implemented on a flow micro reactor system. Keywords: DFT; diastereoselective reaction

• the years [31]. We have already reported a domino aldol–aldol–hemiacetal process that furnishes racemic tetrahydro-2H-pyran-2,4-diols in a highly stereoselective manner (Scheme 1) [30][31][32][33][34][35][36][37]. In this paper, the domino aldol–aldol–hemiacetal reaction involving several metals (Al

• . The larger the amount of aldehyde in the reaction, the higher is the yield of monoaldol product 6a, which supports a thermodynamically controlled equilibrium as further confirmed by the following observations: (1) with gallium(III) two diastereomeric tetrahydro-2H-pyran-2,4-diols are formed at 0 °C

Iridium/N-heterocyclic carbene-catalyzed C–H borylation of arenes by diisopropylaminoborane

• Mamoru Tobisu,
• Takuya Igarashi and
• Naoto Chatani

Beilstein J. Org. Chem. 2016, 12, 654–661, doi:10.3762/bjoc.12.65

• ) complex with 1,3-dicyclohexylimidazol-2-ylidene is found to efficiently catalyze the borylation of arenes and heteroarenes. The resulting aminoborylated products can be converted to the corresponding boronic acid derivatives simply by treatment with suitable diols or diamines. Keywords: boronic acid; C–H

• the synthetic advantage of allowing various substituents to be introduced onto the boron atom during the work-up stage simply by changing the reagents added. For example, addition of different diols delivered the corresponding boronic esters 10-Bnep and 10-Bmep (Scheme 2, bottom). It was also possible

Self and directed assembly: people and molecules

• Tony D. James

Beilstein J. Org. Chem. 2016, 12, 391–405, doi:10.3762/bjoc.12.42

• elements and developed an AND logic system for “cations” and “diols” (Figure 6) [51][52]. In 1998 Michael Bell from Beckman Coulter approached me about working together on a fluorescent glucose sensor system. Therefore, in July and few weeks after the birth of my son Joseph “Joey” Hiro Furukawa James, I

• the enantiomeric excess of the original scalemic mixture of binol (diol) or amine (Figure 15). The three-component system was very versatile and we could use the complexes to determine the enantiomeric excess (ee) of amines [69][70], diamines [71], amino alcohols [72], hydroxylamines [73] and diols

Highly stable and reusable immobilized formate dehydrogenases: Promising biocatalysts for in situ regeneration of NADH

• Barış Binay,
• Dilek Alagöz,
• Deniz Yildirim,
• Ayhan Çelik and
• S. Seyhan Tükel

Beilstein J. Org. Chem. 2016, 12, 271–277, doi:10.3762/bjoc.12.29

• [30]. In this study, Immobead 150 support was kept in 1 M acetic acid solution to produce vicinal diols and then the formed diols were oxidatively cleaved with NaIO4 to produce aldehyde groups onto the support (Figure 1c). The amount of bound protein was determined as 90% of the initial loading

Spiro-fused carbohydrate oxazoline ligands: Synthesis and application as enantio-discrimination agents in asymmetric allylic alkylation

• Jochen Kraft,
• Martin Golkowski and
• Thomas Ziegler

Beilstein J. Org. Chem. 2016, 12, 166–171, doi:10.3762/bjoc.12.18

• acidic conditions gave the corresponding diols 3 [20] and 4 as anomeric mixtures. Condensation of the latter with thiocyanic acid in a Ritter-type reaction according to a slightly modified procedure described by Tatibouët et al. [21] gave an anomeric mixture of 1,3-oxazolidin-2-thiones 5 and 6

Assembly of synthetic Aβ miniamyloids on polyol templates

• Sebastian Nils Fischer and
• Armin Geyer

Beilstein J. Org. Chem. 2015, 11, 2646–2653, doi:10.3762/bjoc.11.284

• avoided only when two different reactive groups are employed; that is why the reversible esterification between boronic acids and diols appeared an attractive solution to us. In a first approach, we planned to condense short peptide boronic acids with polyol templates for the assembly of an Aβ-dimer. The

• diols on the template must be separated from each other far enough to exclude the simultaneous formation of mixtures of 5- and 6-membered boronic esters. However, the oligosaccharides, which are available with a consistent oligomerization degree of dimer, trimer, tetramer and higher, are known to have

Recent advances in copper-catalyzed asymmetric coupling reactions

• Fengtao Zhou and
• Qian Cai

Beilstein J. Org. Chem. 2015, 11, 2600–2615, doi:10.3762/bjoc.11.280

• -halophenoxyl)-1,3-diols by the same group [54]. However, the palladium catalytic systems suffered from limited substrate scope and poor efficiency and enantioselectivity for the formation of quaternary stereocenters. Recently, Cai et al. carried out such couplings using a CuI/cyclized diamine catalytic system

Cu(I)-catalyzed N,N’-diarylation of natural diamines and polyamines with aryl iodides

• Svetlana P. Panchenko,
• Alexei D. Averin,
• Maksim V. Anokhin,
• Olga A. Maloshitskaya and
• Irina P. Beletskaya

Beilstein J. Org. Chem. 2015, 11, 2297–2305, doi:10.3762/bjoc.11.250

• the literature. One of them employs an iridium-based catalyst with amidophosphonate as the ligand which allows to convert aminoalcohols into N-monoaryl-substituted diamines by the reaction with arylamines [20]. Another method uses a bimetallic catalyst (Pt–Sn/γ-Al2O3) in the reactions of diols with

Design and synthesis of propellane derivatives and oxa-bowls via ring-rearrangement metathesis as a key step

• Sambasivarao Kotha and
• Rama Gunta

Beilstein J. Org. Chem. 2015, 11, 1727–1731, doi:10.3762/bjoc.11.188

• with a minor amount of compound 9 (8%). The formation of compound 9 may be explained on the basis of a retro-DA reaction [36] followed by reduction and elimination. In the same way, reduction of C-allyl compound 4b under similar reaction conditions gave diol 8b in 88% yield. In the next step, diols 8a

Dicarboxylic esters: Useful tools for the biocatalyzed synthesis of hybrid compounds and polymers

• Ivan Bassanini,
• Karl Hult and
• Sergio Riva

Beilstein J. Org. Chem. 2015, 11, 1583–1595, doi:10.3762/bjoc.11.174

• beginning of the use of lipases in organic solvents. In 1984 Okumura et al. [48] produced oligomers of several dicarboxylic acids (C6 to C14) in combination with several diols (C2 and C3). Since then the use of lipase-catalyzed preparation of polymers has grow very much and has been reviewed many times (see

• -mercaptosuccinate) could be oxidized by air in DMSO to form a cross-linked insoluble material (Figure 12). In a subsequent paper, the same laboratory prepared different mercaptosuccinate polymers with several diols. In addition they showed that the material cross-linked by air oxidation could be reversibly reduced

• by tributylphosphine to recover the reduced soluble polymer [64]. In a recent review, Khan et al. summarized the synthesis of polymers based on C-5-substituted isophthalates (36, Figure 13) and diols [65]. Using hydroxy or amine groups at C-5 afforded polymers, which could be further modified by

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

• representative range of aldehydes and ketones using dispersions of P25 with soft UVA in MeCN/MeOH (9:1) as solvent [79]. Aromatic aldehydes yielded the corresponding primary alcohols along with pinacol byproducts. Control experiments confirmed that these diols were formed by the well-known photochemical coupling

Cross-metathesis reaction of α- and β-vinyl C-glycosides with alkenes

• Ivan Šnajdr,
• Kamil Parkan,
• Filip Hessler and
• Martin Kotora

Beilstein J. Org. Chem. 2015, 11, 1392–1397, doi:10.3762/bjoc.11.150

• -deoxyribosides [15]. Finally, there is also a method utilizing an excess of vinylmagnesium bromide in the reaction with 3,5-bis-O-TBDPS-protected 2-deoxy-D-ribofuranose giving rise to a mixture of diastereoisomeric diols. The diasteroisomers were separated and cyclized in the presence of MsCl to the

Selected synthetic strategies to cyclophanes

• Sambasivarao Kotha,
• Mukesh E. Shirbhate and
• Gopalkrushna T. Waghule

Beilstein J. Org. Chem. 2015, 11, 1274–1331, doi:10.3762/bjoc.11.142

• , dibromide 83 was converted to bis-aldehyde 84. Finally, McMurry coupling of dialdehyde 84 provided the cyclophane derivative 85 (28%). Yamoto and co-workers have reported the synthesis of medium-sized cyclophanes, [2.n]metacyclophane-1,2-diols 86 and 87 by using the McMurry coupling as a key step (Figure 8

• was explained on the basis of a tandem isomerization of a terminal double bond followed by the macrocyclization with G-II (13). Finally, the oxidation of diols 186 and 189 generated cyclophanes 187 and 190, respectively (Scheme 30). Guan and coworkers [154] have reported a novel synthetic approach to

Novel stereocontrolled syntheses of tashiromine and epitashiromine

• Loránd Kiss,
• Enikő Forró and
• Ferenc Fülöp

Beilstein J. Org. Chem. 2015, 11, 596–603, doi:10.3762/bjoc.11.66

• convenient route for the preparation of N-heterocyclic β-amino acid derivatives [40][41] or for the stereocontrolled synthesis of functionalized cispentacins [42] and their acyclic counterparts [43][44] (Figure 5). The oxidative ring cleavage of various vicinal diols and the transformation of the resulting

• dialdehyde intermediates has been efficiently applied in recent years for the synthesis of a series of valuable organic molecules [45][46][47][48][49][50][51][52]. In particular, Davies and co-workers have utilized the oxidative ring opening of cyclic vicinal diols followed by ring closure for access to

Diastereoselective and enantioselective conjugate addition reactions utilizing α,β-unsaturated amides and lactams

• Katherine M. Byrd

Beilstein J. Org. Chem. 2015, 11, 530–562, doi:10.3762/bjoc.11.60

• method to synthesize protected syn-1,3-diols by performing intramolecular conjugate additions to a series of α,β-unsaturated esters and amides [71] (Scheme 8). Upon treatment of 24 with KHMDS and benzyaldehyde, a hemiacetal forms which provides the alkoxide nucleophile for the DCA reaction. These