Gram-scale preparation of negative-type liquid crystals with a CF₂CF₂-carbocycle unit via an improved short-step synthetic protocol

• Tatsuya Kumon,
• Shohei Hashishita,
• Takumi Kida,
• Shigeyuki Yamada,
• Takashi Ishihara and
• Tsutomu Konno

Beilstein J. Org. Chem. 2018, 14, 148–154, doi:10.3762/bjoc.14.10

• influence of a large amount of phosphorus oxychloride in pyridine at 90 °C for 1 d according to the previous literature [12]. On the other hand, 4a could also be transformed into the corresponding bisxanthate derivative 9a according to the literature procedure [13]. Without further purification, 9a was

Aminosugar-based immunomodulator lipid A: synthetic approaches

• Alla Zamyatina

Beilstein J. Org. Chem. 2018, 14, 25–53, doi:10.3762/bjoc.14.3

• lipid A and galactosamine-modified Francisella lipid A. Particular emphasis is put on the stereoselective construction of binary glycosyl phosphodiester fragments connecting the anomeric centers of two aminosugars as well as on the advanced P(III)-phosphorus chemistry behind the assembly of zwitterionic

CF₃SO₂X (X = Na, Cl) as reagents for trifluoromethylation, trifluoromethylsulfenyl-, -sulfinyl- and -sulfonylation and chlorination. Part 2: Use of CF₃SO₂Cl

• Hélène Chachignon,
• Hélène Guyon and
• Dominique Cahard

Beilstein J. Org. Chem. 2017, 13, 2800–2818, doi:10.3762/bjoc.13.273

• of an halogen bond between the positive electrostatic potential on the outer side of the chlorine atom and the lone pair of the phosphorus atom of the phosphine. This phenomenon indeed triggered the cleavage of the S–Cl bond, producing chlorophosphonium sulfinate 40, which was then readily converted

CF₃SO₂X (X = Na, Cl) as reagents for trifluoromethylation, trifluoromethylsulfenyl-, -sulfinyl- and -sulfonylation. Part 1: Use of CF₃SO₂Na

• Hélène Guyon,
• Hélène Chachignon and
• Dominique Cahard

Beilstein J. Org. Chem. 2017, 13, 2764–2799, doi:10.3762/bjoc.13.272

Vinylphosphonium and 2-aminovinylphosphonium salts – preparation and applications in organic synthesis

• Anna Kuźnik,
• Roman Mazurkiewicz and
• Beata Fryczkowska

Beilstein J. Org. Chem. 2017, 13, 2710–2738, doi:10.3762/bjoc.13.269

• attention is paid to the use of these compounds as building blocks for the synthesis of carbo- and heterocyclic systems after their prior transformation into the corresponding phosphorus ylides, followed by the intramolecular Wittig reaction with various types of nucleophiles containing a carbonyl function

• in their structures. Keywords: 2-aminovinylphosphonium salts; nucleophilic addition; phosphorus ylides; vinylphosphonium salts; Wittig reaction; Introduction Vinylphosphonium salts have been known for a long time, although significant interest in these compounds dates back to 1964, when Schweizer

• found that they can be converted to phosphorus ylides by the addition of a nucleophile to the carbon atom at the β-position of the vinyl group (Scheme 1) [1]. Particularly widely used in organic synthesis are reactions involving the addition of a nucleophile containing a carbonyl group in its molecule

A novel synthetic approach to hydroimidazo[1,5-b]pyridazines by the recyclization of itaconimides and HPLC–HRMS monitoring of the reaction pathway

• Dmitry Yu. Vandyshev,
• Khidmet S. Shikhaliev,
• Andrey Yu. Potapov,
• Michael Yu. Krysin,
• Fedor I. Zubkov and
• Lyudmila V. Sapronova

Beilstein J. Org. Chem. 2017, 13, 2561–2568, doi:10.3762/bjoc.13.252

• 1-aminoimidazoles to build the pyridazine core (route B, Scheme 2 and Scheme 3). Following route A (Scheme 1), the aminomethylpyridazine derivatives are either pre-acylated and subsequently cyclized with phosphorus oxychloride [12][13][19][23], or the formation of imidazo[1,5-b]pyridazines occurs as

Syntheses, structures, and stabilities of aliphatic and aromatic fluorous iodine(I) and iodine(III) compounds: the role of iodine Lewis basicity

• Tathagata Mukherjee,
• Soumik Biswas,
• Andreas Ehnbom,
• Subrata K. Ghosh,
• Ibrahim El-Zoghbi,
• Nattamai Bhuvanesh,
• Hassan S. Bazzi and
• John A. Gladysz

Beilstein J. Org. Chem. 2017, 13, 2486–2501, doi:10.3762/bjoc.13.246

• ) species [11][20][21][22]. Recently, our attention has been directed at two potential applications of iodine containing fluorous compounds. One involves new approaches to phosphorus–carbon bond formation using fluorous alkyl and aryl iodides [23][24]. The other involves the use of fluorous iodine(III

• this study was to bridge several strategic gaps regarding highly fluorophilic building blocks for the formation of (1) phosphorus–carbon bonded species, and (2) iodine(III) dichloride reagents. For example, aliphatic species of the formula RfnCH2CH2ICl2 are unstable [17]. However, analogs with one less

Electron-deficient pyridinium salts/thiourea cooperative catalyzed O-glycosylation via activation of O-glycosyl trichloroacetimidate donors

• Mukta Shaw,
• Yogesh Kumar,
• Rima Thakur and
• Amit Kumar

Beilstein J. Org. Chem. 2017, 13, 2385–2395, doi:10.3762/bjoc.13.236

• with phosphorus acids) for stereoselective O-glycoside bond formation [30]. Similarly, Galan et al. reported a method for the preparation of 2-deoxyglycosides from glycals under the influence of cooperative catalysis (chiral phosphoric acids/thiourea derivatives) [31]. Encouraged by these reports and

Is the tungsten(IV) complex (NEt₄)₂[WO(mnt)₂] a functional analogue of acetylene hydratase?

• Matthias Schreyer and
• Lukas Hintermann

Beilstein J. Org. Chem. 2017, 13, 2332–2339, doi:10.3762/bjoc.13.230

• ethyne to acetaldehdye [13]. A commercial acetylene pressure bottle (purity grade 2.6, i.e., 99.6%, containing ≤5 ppm sulfur or phosphorus compounds) was available for the experiment. Gas was first bubbled through a solution of 1 in acetonitrile–water (2:1) at 40 °C, then the vessel was closed and the

Synthesis and photophysical properties of novel benzophospholo[3,2-b]indole derivatives

• Mio Matsumura,
• Mizuki Yamada,
• Atsuya Muranaka,
• Misae Kanai,
• Naoki Kakusawa,
• Daisuke Hashizume,
• Masanobu Uchiyama and
• Shuji Yasuike

Beilstein J. Org. Chem. 2017, 13, 2304–2309, doi:10.3762/bjoc.13.226

• -dimethylaniline. Using the obtained benzophosphole-fused indole as a common starting material, simple modifications were carried out at the phosphorus center of the phosphole, synthesizing various functionalized analogs. The X-ray structure analysis of trivalent phosphole and phosphine oxide showed that the fused

• ; photophysical property; Introduction The chemistry of phospholes, fully unsaturated five-membered heterocyclic rings containing a phosphorus element, has drawn much attention in terms of the development of synthetic methods and elucidation of its spectroscopic properties for applications in organic field

• -effect transistors (OFETs) and luminescent materials [1][2][3][4][5][6][7][8][9]. The phosphorous atom of trivalent phosphorus compounds has a high chemical reactivity. Therefore, several reactions on the phosphorus atom such as oxidation, alkylation, and coordination to a Lewis acid can produce the

Phosphonic acid: preparation and applications

• Charlotte M. Sevrain,
• Mathieu Berchel,
• Hélène Couthon and
• Paul-Alain Jaffrès

Beilstein J. Org. Chem. 2017, 13, 2186–2213, doi:10.3762/bjoc.13.219

• Charlotte M. Sevrain Mathieu Berchel Helene Couthon Paul-Alain Jaffres CEMCA UMR CNRS 6521, Université de Brest, IBSAM. 6 Avenue Victor Le Gorgeu, 29238 Brest, France 10.3762/bjoc.13.219 Abstract The phosphonic acid functional group, which is characterized by a phosphorus atom bonded to three

• phosphorus-containing functional groups [2], on specific applications (hybrid materials [3], surface modification [4], oil industry [5]) or dedicated to a family of compounds (e.g., aminophosphonic acids [6], organometallic phosphonic acids [7]). However, no recent review was focused on the different methods

• methylphosphonic acid, Figure 2, the P=O bond length is 1.4993(11) Å, the two other P–O bond lengths are 1.5441(11) Å and 1.5443(12) Å and the P–C bond is 1.7586(17) Å). The bond angles at the phosphorus atom are ranging from 103.46(8)° to 112.86(7)° for methylphosphonic acid, indicating a distorted tetrahedral

Mechanochemical synthesis of small organic molecules

• Tapas Kumar Achar,
• Anima Bose and
• Prasenjit Mal

Beilstein J. Org. Chem. 2017, 13, 1907–1931, doi:10.3762/bjoc.13.186

• Reaction Pecharsky and co-workers reported the solvent-free mechanochemical synthesis of phosphonium salts [54] and phosphorus ylides [55] in the presence of the weak base K2CO3. Mechanochemically prepared phosphorous ylide from triphenylphosphine in presence of K2CO3 was utilized for a one-pot solvent

• ), high yielding, room temperature conditions, etc. Previously reported solvent-based synthesis required reflux for 3 days to get 30–40% yield [169]. Miscellaneous bond formation reaction Carbon–phosphorus bond synthesis Recently, Wang and co-workers reported the first carbon–phosphorous (C–P) bond

Pd(OAc)₂/Ph₃P-catalyzed dimerization of isoprene and synthesis of monoterpenic heterocycles

• Dominik Kellner,
• Maximilian Weger,
• Andrea Gini and
• Olga García Mancheño

Beilstein J. Org. Chem. 2017, 13, 1807–1815, doi:10.3762/bjoc.13.175

• Beller and co-workers (Scheme 1, reaction 2) [33]. The use of NHCs proved to be the key, since the more accessible monodentated phosphorus ligands such as triphenyl (Ph3P) or tricyclohexyl (Cy3P) phosphines showed a significant lower efficiency and different selectivity with the same palladium source Pd

A novel approach to oxoisoaporphine alkaloids via regioselective metalation of alkoxy isoquinolines

• Benedikt C. Melzer and
• Franz Bracher

Beilstein J. Org. Chem. 2017, 13, 1564–1571, doi:10.3762/bjoc.13.156

• reaction conditions. As an alternative reagent for the acylation of arenes with esters Eaton’s reagent (phosphorus pentoxide, 7.7 wt % in methanesulfonic acid) has been described in the literature [28][29]. Eaton’s reagent has advantages over polyphosphoric acid as it is an easy to handle, non-viscous and

Chemical systems, chemical contiguity and the emergence of life

• Terrence P. Kee and
• Pierre-Alain Monnard

Beilstein J. Org. Chem. 2017, 13, 1551–1563, doi:10.3762/bjoc.13.155

• phosphorus (P) in +5 oxidation state, is puzzling to some extent as this element is today a limiting nutrient for life [42]. But the prebiotic availability of P is now being far better understood [43][44][45]. In addition, the reactivity of phosphate and polyphosphate is low in aqueous media in the absence

Synthesis of oligonucleotides on a soluble support

• Harri Lönnberg

Beilstein J. Org. Chem. 2017, 13, 1368–1387, doi:10.3762/bjoc.13.134

• strategy may be utilized, but the stepwise linear approach proceeding from the 3´- to the 5´-terminus of ON is nowadays almost exclusively exploited [1][2]. The coupling reaction may take place either at oxidation level III or V of phosphorus. Owing to higher reactivity of P(III) centers, appropriately

• derivatives 2-ethyl- and 2-benzylthiotetrazole [8] or 4,5-dicyanoimidazole [9]. The activator has a dual role donating a proton to the departing dialkylamino group and attacking as an anionic species on phosphorus [10]. Nucleoside H-phosphonates are, in turn, converted in situ to reactive mixed anhydrides

Phosphorus pentasulfide mediated conversion of organic thiocyanates to thiols

• Chandra Kant Maurya,
• Avik Mazumder and
• Pradeep Kumar Gupta

Beilstein J. Org. Chem. 2017, 13, 1184–1188, doi:10.3762/bjoc.13.117

• /bjoc.13.117 Abstract In this paper we report an efficient and mild procedure for the conversion of organic thiocyanates to thiols in the presence of phosphorus pentasulfide (P2S5) in refluxing toluene. The method avoids the use of expensive and hazardous transition metals and harsh reducing agents, as

• required by reported methods, and provides an attractive alternative to the existing methods for the conversion of organic thiocyanates to thiols. Keywords: dithiocarbamate; phosphorus pentasulfide; thiocyanate; thiol; toluene; Introduction Thiols constitute an important group of sulfur-containing

• -reductive conditions (Scheme 1). Phosphorus pentasulfide (P2S5), a commercially available reagent, has widely been employed in organic synthesis for numerous applications [18]. The synthetic protocol described in this paper makes use of this reagent to provide an efficient and single step procedure for the

Synthesis of 1-indanones with a broad range of biological activity

• Marika Turek,
• Dorota Szczęsna,
• Marek Koprowski and
• Piotr Bałczewski

Beilstein J. Org. Chem. 2017, 13, 451–494, doi:10.3762/bjoc.13.48

• diesters: In 1951, Gilmore has demonstrated that use of esters, rather than free arylpropionic acids in phosphoric acid, in the presence of phosphorus pentoxide also led to 1-indanones in equally good or even better yields [32]. Transition metal complexes have been used by Negishi et al. as catalysts in

Structure–efficiency relationships of cyclodextrin scavengers in the hydrolytic degradation of organophosphorus compounds

• Sophie Letort,
• Michaël Bosco,
• Benedetta Cornelio,
• Frédérique Brégier,
• Sébastien Daulon,
• Géraldine Gouhier and
• François Estour

Beilstein J. Org. Chem. 2017, 13, 417–427, doi:10.3762/bjoc.13.45

• organophosphorus compound into p-nitrophenol compared to IBA alone. Compound 2 was the most effective, while the slowest pesticide hydrolysis was observed in the presence of derivative 3. These results provided evidence that the relative position of the reactive group towards the phosphorus atom and the vicinity

• paraoxon while IBA alone displayed a generally lower and similar efficiency towards these three pesticides. This suggests that the electrophilic character of the phosphorus atom plays a role in the detoxification process (methyl parathion versus methyl paraoxon). Moreover, the strength and depth of the

• vicinity of the imidazole substituent to the active group confirmed its benefit to accelerate the soman degradation [33]. However, many parameters are involved in the detoxification process. It is known that an aromatic group attached to a phosphorus atom can interact with the cyclodextrin cavity wherefore

Synthesis and optical properties of new 5'-aryl-substituted 2,5-bis(3-decyl-2,2'-bithiophen-5-yl)-1,3,4-oxadiazoles

• Anastasia S. Kostyuchenko,
• Tatyana Yu. Zheleznova,
• Anton J. Stasyuk,
• Aleksandra Kurowska,
• Wojciech Domagala,
• Adam Pron and
• Alexander S. Fisyuk

Beilstein J. Org. Chem. 2017, 13, 313–322, doi:10.3762/bjoc.13.34

• the obtained diacylated hydrazines 14b–g were in the range of 58–74% (Scheme 3). Finally, heating the diacyl hydrazines 14b–g in phosphorus oxychloride led to the formation of the desired 1,3,4-oxadiazoles 15b–g. The product yields were between 65–94% after purification by column chromatography

A novel method for heterocyclic amide–thioamide transformations

• Walid Fathalla,
• Ibrahim A. I. Ali and
• Pavel Pazdera

Beilstein J. Org. Chem. 2017, 13, 174–181, doi:10.3762/bjoc.13.20

• ; for instance, Lawesson's reagent (2,4-bis(4-methoxyphenyl)-1,3-dithia-2,4-diphosphetane 2,4-disulfide) [1][2][3], Berzelius reagent [4][5][6] (P4S10), and phosphorus pentasulfide [7] in dry toluene, xylene or pyridine under reflux conditions. A two-step approach for the purpose of thiation of

First DMAP-mediated direct conversion of Morita–Baylis–Hillman alcohols into γ-ketoallylphosphonates: Synthesis of γ-aminoallylphosphonates

• Marwa Ayadi,
• Haitham Elleuch,
• Emmanuel Vrancken and
• Farhat Rezgui

Beilstein J. Org. Chem. 2016, 12, 2906–2915, doi:10.3762/bjoc.12.290

• has been reported through a palladium-catalyzed hydrogenation of α-fluorovinylphosphonates [43]. In continuation of our interest [21] in the construction of carbon–phosphorus bonds using both cyclic and acyclic MBH adducts, we report herein, for the first time, a direct and facile access to γ

New syntheses of (±)-tashiromine and (±)-epitashiromine via enaminone intermediates

• Darren L. Riley,
• Joseph P. Michael and
• Charles B. de Koning

Beilstein J. Org. Chem. 2016, 12, 2609–2613, doi:10.3762/bjoc.12.256

• Carius tube at 250 °C, affording alcohol 5 in 81% yield. The subsequent protection of the primary alcohol as acetate 6 (87% yield), followed by thionation with phosphorus pentasulfide using the Brillon procedure [29] afforded thiolactam 3 in 90% yield. The succeeding Eschenmoser reaction with α

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

• -butoxide anion and acetophenone (227). These steps occur presumably in a concerted manner. Finally, the protonation of the tert-butoxide anion results in the formation of tert-butanol (228). As alternative bases Et3N [338][339], phosphorus ylides [340] and LiOH [341][342] can be used and the Kornblum

Rh-Catalyzed reductive Mannich-type reaction and its application towards the synthesis of (±)-ezetimibe

• Motoyuki Isoda,
• Kazuyuki Sato,
• Yurika Kunugi,
• Satsuki Tokonishi,
• Atsushi Tarui,
• Masaaki Omote,
• Hideki Minami and
• Akira Ando

Beilstein J. Org. Chem. 2016, 12, 1608–1615, doi:10.3762/bjoc.12.157

• phosphorus pentoxide directly before use, respectively. All imines were prepared from corresponding aldehydes and amines. Methyl acrylate was distilled directly before use. Other commercially available reagents were used without further purification. All experiments were carried out under an argon atmosphere