Inclusion complexes of 2-methoxyestradiol with dimethylated and permethylated β-cyclodextrins: models for cyclodextrin–steroid interaction

• Mino R. Caira,
• Susan A. Bourne,
• Halima Samsodien and
• Vincent J. Smith

Beilstein J. Org. Chem. 2015, 11, 2616–2630, doi:10.3762/bjoc.11.281

• oil and heated from 30 °C at 10 K/min, were initially clear. Bubbles appearing at ≈80 °C indicated commencement of the release of included water. This process appeared to be continuous, posing difficulty in estimating the temperature corresponding to complete dehydration. The anhydrous phase began to

• discolour at ≈290 °C, indicating the onset of slow decomposition. Vigorous bubbling and the dark brown colour that developed at ≈400 °C signified the onset of rapid final complex decomposition. Corresponding to these events, the DSC trace displayed an endotherm for dehydration in the approximate range 54

• –105 °C (peak temperature 80 °C), and a sequence of two small endotherms, a large exotherm, and a small endotherm, all of them spanning the range ≈255–350 °C, attributed to final dehydration and the onset of complex decomposition. The absence of any endothermic effect for the fusion of pure 2ME was

Synthesis of Xenia diterpenoids and related metabolites isolated from marine organisms

• Tatjana Huber,
• Lara Weisheit and
• Thomas Magauer

Beilstein J. Org. Chem. 2015, 11, 2521–2539, doi:10.3762/bjoc.11.273

• literature-known procedure [47]. Regioselective reduction with sodium borohydride, followed by dehydration under Mitsunobu conditions and silylation of the tertiary alcohol furnished trimethylsiloxy ketone 78. The ketone functionality was then diastereoselectively reduced under Corey–Bakshi–Shibata

• function in bicycle 93. The side chain of blumiolide C was introduced by an aldol reaction between lactone 93 and aldehyde 94. In the final sequence, blumiolide C (11) was obtained via stereospecific dehydration, removal of the para-methoxybenzyl ether and oxidation. In summary, the total synthesis of

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

• , the archetypal super-enzyme for which catalytic rates reach the limits of diffusion [30][31]. CO2 consumed by enzymes is therefore efficiently replenished through rapid HCO3− dehydration (Figure 2). Living organisms have developed various mechanisms to increase the effective concentration of CO2

• . Zeolite systems utilising Ge or Si, recently described, were able to efficiently dehydrogenate formic acid. This was guided through computational calculations, allowing the design of a zeolite catalyst displaying over 94% selectivity over the counter-productive formate dehydration reaction [145]. The

Fe(II)/Et₃N-Relay-catalyzed domino reaction of isoxazoles with imidazolium salts in the synthesis of methyl 4-imidazolylpyrrole-2-carboxylates, its ylide and betaine derivatives

• Ekaterina E. Galenko,
• Olesya A. Tomashenko,
• Alexander F. Khlebnikov,
• Mikhail S. Novikov and
• Taras L. Panikorovskii

Beilstein J. Org. Chem. 2015, 11, 1732–1740, doi:10.3762/bjoc.11.189

• complexes of pyrrole-2-carboxylic acid [23][24][25]. In some cases these complexes were prepared via dehydration of the corresponding proline complexes [25]. Substituted pyrrole-2-carboxylic acids as ligands of complexes are seldom used and are only exemplified by complexes of indole-2-carboxylic acid [26

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

• benzene taken from an activated alumina column. The primary sulfur product of the reaction is probably benzenesulfinic acid, which is thermally unstable, self-condensing with dehydration [29]. Thus, it is possible that either water or a reactive equivalent of water (such as Bu3SnOH) is formed during the

Synthesis of alpha-tetrasubstituted triazoles by copper-catalyzed silyl deprotection/azide cycloaddition

• Zachary L. Palchak,
• Paula T. Nguyen and
• Catharine H. Larsen

Beilstein J. Org. Chem. 2015, 11, 1425–1433, doi:10.3762/bjoc.11.154

• ketimine is followed by stoichiometric alkynylation with a trimethylsilyl-protected alkynyllithium reagent. Removal of the silyl and sulfinyl protecting groups allows for CuAAC with a resin-bound azide. Acylation of the amine followed by dehydration yields the active alpha-tetrasubstituted triazole [7

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

• treated with LAH to generate diol 266 (72–92%). The dehydration of diol 266 with pyridinium p-toluenesulfonate in benzene gave diolefin 267. [2 + 2] Photocycloaddition of diolefin 267 was carried out by irradiation with a 400 W high-pressure Hg lamp (Pyrex filter) in benzene for 26–92 h. After evaporation

The synthesis of active pharmaceutical ingredients (APIs) using continuous flow chemistry

• Marcus Baumann and
• Ian R. Baxendale

Beilstein J. Org. Chem. 2015, 11, 1194–1219, doi:10.3762/bjoc.11.134

• the scaled synthesis of NBI-75043 (3) [41], a continuous dehydration process to deliver over 5 kg of dehydropristane 4, a precursor of the immunoactivating agent pristane [42] or the flow synthesis of hydroxamic acids by a procedure that was also applied to the preparation of suberoylanilide

• under the acidic conditions promotes dehydration. The product is isolated as the in situ formed hydrochloride salt of amitriptyline (127). Solution delivery As the previous examples have demonstrated, the development of an efficient flow process is often the result of designing and implementing a new

Novel carbocationic rearrangements of 1-styrylpropargyl alcohols

• Christine Basmadjian,
• Fan Zhang and
• Laurent Désaubry

Beilstein J. Org. Chem. 2015, 11, 1017–1022, doi:10.3762/bjoc.11.114

• Christine Basmadjian Fan Zhang Laurent Desaubry Laboratory of Therapeutic Innovation (UMR 7200), University of Strasbourg - CNRS, Faculty of Pharmacy, 67401 Illkirch, France 10.3762/bjoc.11.114 Abstract The dehydration and subsequent cyclization reactions of 1-styrylpropargyl alcohols was

A new and convenient synthetic way to 2-substituted thieno[2,3-b]indoles

• Roman A. Irgashev,
• Arseny A. Karmatsky,
• Gennady L. Rusinov and
• Valery N. Charushin

Beilstein J. Org. Chem. 2015, 11, 1000–1007, doi:10.3762/bjoc.11.112

• conventional path [32] (Path C) leading to the aldol adduct 9a (which was further used without purification in all our experiments), its dehydration into 10a, reduction of the latter to indolin-2-ones 11a, and finally cyclization of 11a by action of Lawesson’s reagent (LR), resulting in the formation of the

• the corresponding acetylated (hetero)arenes 8a–m. Dehydration of the initially obtained aldol-type adducts into 3-(2-oxo-2-(hetero)arylethylidene)indolin-2-ones 10 has been carried out in acetic acid solution with addition of hydrochloric acid (method A), or in CH2Cl2 solution with an excess of SOCl2

Trifluoromethyl-substituted tetrathiafulvalenes

• Olivier Jeannin,
• Frédéric Barrière and
• Marc Fourmigué

Beilstein J. Org. Chem. 2015, 11, 647–658, doi:10.3762/bjoc.11.73

• MeOH gives the corresponding primary amide 7 in 63% yield. Its dehydration with POCl3 in sulfolane gives 2ac in 60% yield. A similar phosphite-based cross-coupling reaction between the bis(trifluoromethyl)-1,3-dithiole-2-one derivative 9cc and the diester derivative 10bb gave the TTF 3bc in 15% yield

Further exploration of the heterocyclic diversity accessible from the allylation chemistry of indigo

• Alireza Shakoori,
• John B. Bremner,
• Mohammed K. Abdel-Hamid,
• Anthony C. Willis,
• Rachada Haritakun and
• Paul A. Keller

Beilstein J. Org. Chem. 2015, 11, 481–492, doi:10.3762/bjoc.11.54

• negative charge for subsequent cyclisation onto the carbonyl forming the 7-membered ring. In Path A, dehydration and cyclisation onto the activated iminium cation 25 could form 17. Path B describes the base-induced deprotonation to form the neutral product 26. While dehydration of 26 could conceivably also

Attempts to prepare an all-carbon indigoid system

• Şeref Yildizhan,
• Henning Hopf and
• Peter G. Jones

Beilstein J. Org. Chem. 2015, 11, 363–372, doi:10.3762/bjoc.11.42

• a dehydration reaction. In both cases only minute amounts of products could be obtained. When trying to purify these by column chromatography on silica gel, the stationary phase turned blue, but no defined products could be isolated. Since it might have been the central conjugated butenedione core

Novel biphenyl-substituted 1,2,4-oxadiazole ferroelectric liquid crystals: synthesis and characterization

• Mahabaleshwara Subrao,
• Dakshina Murthy Potukuchi,
• Girish Sharada Ramachandra,
• Poornima Bhagavath,
• Sangeetha G. Bhat and
• Srinivasulu Maddasani

Beilstein J. Org. Chem. 2015, 11, 233–241, doi:10.3762/bjoc.11.26

• The synthesis of 1,2,4-oxadiazoles involves [30] a single stage dehydration of O-acylated amidoximes via a reaction between amidoximes and derivatives of carbonyl compounds (esters, amides, acids, acid chlorides, aldehydes, etc.). Otherwise, the reaction is based on the 1,3-dipolar cycloaddition of N

Inclusion of trans-resveratrol in methylated cyclodextrins: synthesis and solid-state structures

• Lee Trollope,
• Dyanne L. Cruickshank,
• Terence Noonan,
• Susan A. Bourne,
• Milena Sorrenti,
• Laura Catenacci and
• Mino R. Caira

Beilstein J. Org. Chem. 2014, 10, 3136–3151, doi:10.3762/bjoc.10.331

• oil and the DSC trace shows a corresponding broad endotherm accompanying the dehydration. However, a sharp endotherm subsequently developed, peaking at ca. 110 °C, interpreted as commencement of complex fusion which overlaps the dehydration process. This coincides with the melting observed in HSM at

• molecules per 1:1 complex unit. The endotherm observed over the range of 30–120 °C appears sharper than expected for solvent loss alone, suggesting simultaneous melting of the complex. The HSM photographs confirm that dehydration is accompanied by complex fusion, the latter spanning a wide temperature range

• -precipitation method and fully characterized by thermal and single crystal X-ray diffraction methods. For the complexes containing the fully methylated hosts TMA and TMB, thermal analysis revealed dehydration overlapping with fusion of the anhydrous complex, followed by final decomposition, whereas the DMB

Modification of physical properties of poly(L-lactic acid) by addition of methyl-β-cyclodextrin

• Toshiyuki Suzuki,
• Ayaka Ei,
• Yoshihisa Takada,
• Hiroki Uehara,
• Takeshi Yamanobe and
• Keiko Takahashi

Beilstein J. Org. Chem. 2014, 10, 2997–3006, doi:10.3762/bjoc.10.318

• observed, except for PLLA. For MeCD, this weight loss arises from dehydration [41][42]. For PL-MCD samples, the weight loss begins at higher temperatures than for MeCD. The weight loss is caused by desorption of chloroform from the MeCD cavity. This weight loss may not be observed if PLLA is included in

Encapsulation of biocides by cyclodextrins: toward synergistic effects against pathogens

• Véronique Nardello-Rataj and
• Loïc Leclercq

Beilstein J. Org. Chem. 2014, 10, 2603–2622, doi:10.3762/bjoc.10.273

• , Dong et al. published on the inclusion of ciprofloxacin by grafting β-CD on cellulose fibers (Figure 8) [65]. The β-CD-grafted cellulose was prepared by the formation of CA-β-CD obtained after the dehydration of the two adjacent carboxyl groups of the citric acid (CA) to form a cyclic anhydride, which

Formal total syntheses of classic natural product target molecules via palladium-catalyzed enantioselective alkylation

• Yiyang Liu,
• Marc Liniger,
• Ryan M. McFadden,
• Jenny L. Roizen,
• Jacquie Malette,
• Corey M. Reeves,
• Douglas C. Behenna,
• Masaki Seto,
• Jimin Kim,
• Justin T. Mohr,
• Scott C. Virgil and
• Brian M. Stoltz

Beilstein J. Org. Chem. 2014, 10, 2501–2512, doi:10.3762/bjoc.10.261

• , terminal alcohol silylation, and tertiary alcohol dehydration, affording methylene cyclohexane (−)-20. Treatment of this silyl ether with Jones reagent simultaneously cleaved the silyl group and oxidized the resulting alcohol, furnishing carboxylic acid (−)-12 in 65% yield. With this enantioenriched acid

Phosphinocyclodextrins as confining units for catalytic metal centres. Applications to carbon–carbon bond forming reactions

• Matthieu Jouffroy,
• Rafael Gramage-Doria,
• David Sémeril,
• Dominique Armspach,
• Dominique Matt,
• Werner Oberhauser and
• Loïc Toupet

Beilstein J. Org. Chem. 2014, 10, 2388–2405, doi:10.3762/bjoc.10.249

• in apical (top) or equatorial (bottom) position. Complexation of a "PdCl(dmba)" unit by HUGPHOS ligands. Reaction of HUGPHOS-1 with [MCl2(PhCN)2] complexes (M = Pd, Pt). Only one isomer with a given MeO–M bond has been drawn. Synthesis of complexes 3–5. Dehydration of Pd(II) complex 5. Synthesis of

Visible light photoredox-catalyzed deoxygenation of alcohols

• Daniel Rackl,
• Viktor Kais,
• Peter Kreitmeier and
• Oliver Reiser

Beilstein J. Org. Chem. 2014, 10, 2157–2165, doi:10.3762/bjoc.10.223

• produced by thermal dehydration of acetic acid [12], the overall sequence to the benzoylated starting material 6e does not require any type of activation reagents such as thionyl chloride or DCC that are often used for ester formation, but ultimately only requires energy in form of heat. After the

Photorelease of phosphates: Mild methods for protecting phosphate derivatives

• Sanjeewa N. Senadheera,
• Abraham L. Yousef and
• Richard S. Givens

Beilstein J. Org. Chem. 2014, 10, 2038–2054, doi:10.3762/bjoc.10.212

• the 5- and 8-positions by H–D exchange [19]. Furthermore, dehydration of 5-(1-hydroxyethyl)-1-naphthol (34) is very efficient, leading to quinone methide 35 which is trapped by solvent MeOH (Scheme 8). The corresponding 4-(1-hydroxyethyl)-1-naphthol, however, is unreactive. Comparisons of the two

Five-membered ring annelation in [2.2]paracyclophanes by aldol condensation

• Henning Hopf,
• Swaminathan Vijay Narayanan and
• Peter G. Jones

Beilstein J. Org. Chem. 2014, 10, 2021–2026, doi:10.3762/bjoc.10.210

• dehydration experiment described below. The most plausible mechanism for the above aldol reaction also favors the discussed structural assignments. As shown above in Scheme 2, the starting material 9 favors a conformation in the solid state in which all carbonyl groups point towards the “inner” space of the

• aldols, we next dehydrated them under acidic conditions. When the syn-isomer 12 was treated with p-toluenesulfonic acid in toluene at room temperature, three dehydration products 18–20 were produced in approximately equal yields. The products were separated by preparative plate chromatography, and the

• , and also furnishes three dehydration products, the anti-configurated diketones 21–23, produced in a 1:3:1 ratio. Again the fully or partially conjugated isomers are deeply colored (intense yellow) and display absorption maxima at 389 and 358 nm, respectively (Scheme 6). For 21 yellow single crystals

Facile synthesis of 1-alkoxy-1H-benzo- and 7-azabenzotriazoles from peptide coupling agents, mechanistic studies, and synthetic applications

• Mahesh K. Lakshman,
• Manish K. Singh,
• Mukesh Kumar,
• Raghu Ram Chamala,
• Vijayender R. Yedulla,
• Domenick Wagner,
• Evan Leung,
• Lijia Yang,
• Asha Matin and
• Sadia Ahmad

Beilstein J. Org. Chem. 2014, 10, 1919–1932, doi:10.3762/bjoc.10.200

• previously described the use of (benzotriazol-1-yloxy)tris(dimethylamino)phosphonium hexafluorophosphate (BOP) for the dehydration of aldoximes to cyanides [22]. In that work, analysis of the reaction course by 31P{1H} NMR did not show the formation of a new phosphorus signal other than that for HMPA, which

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

• dehydration and cyclization steps of the reaction owing to its acidic properties. The reaction variant involving the corresponding sugar aldehyde 75, 4-aminopent-3-en-2-one and ethyl 3-oxobutanoate allowed to obtain unsymmetrical products 93. Galactose-6'-aldehyde-derived counterparts of the symmetrical

Rasta resin–triphenylphosphine oxides and their use as recyclable heterogeneous reagent precursors in halogenation reactions

• Xuanshu Xia and
• Patrick H. Toy

Beilstein J. Org. Chem. 2014, 10, 1397–1405, doi:10.3762/bjoc.10.143

• the dehydration of oximes 12 to form nitriles 13. Capitalizing on the fact that 1 is formed as a byproduct from 3a,b in each of these reactions, Denton and co-workers have recently combined the Masaki–Fukui reaction with many of the functional group transformation outlined in Scheme 2, in one-pot

• halophosphonium salts in Appel and dehydration reactions [44]. This work utilized a commercially available polymer-supported phosphine oxide based on the Merrifield resin architecture, and it is noteworthy that the reactions reported in this manuscript required a 6-fold excess of the halophosphonium salt compared