Phosphinate-containing heterocycles: A mini-review

• Olivier Berger and
• Jean-Luc Montchamp

Beilstein J. Org. Chem. 2014, 10, 732–740, doi:10.3762/bjoc.10.67

• rare. The growing availability of synthetic methods will undoubtedly change this situation in the near future. Keywords: amino acid; heterocyle; organophosphorus; phosphinic; phosphorus; Introduction The preparation of P-heterocycles has been the subject of many studies over the years, and the field

A novel family of (1-aminoalkyl)(trifluoromethyl)- and -(difluoromethyl)phosphinic acids – analogues of α-amino acids

• Natalia V. Pavlenko,
• Tatiana I. Oos,
• Yurii L. Yagupolskii,
• Igor I. Gerus,
• Uwe Doeller and
• Lothar Willms

Beilstein J. Org. Chem. 2014, 10, 722–731, doi:10.3762/bjoc.10.66

• , bearing side chain C–F linkages are well documented in a review [10]. The isolation of phosphinothricin, a naturally occurring phosphorus analogue of glutamic acid and the discovery of its antibiotic, fungicidal and herbicidal properties [11] has led to an increased activity in the study of

• methylphosphinic acid analogues of the protein amino acids [12] and those of glycine [13], alanine [14], valine [14], leucine [15], proline [16], aspartic [17] and glutamic [11] acids and GABA [18] have been described. But almost nothing is known about phosphorus isosters of aminocarboxylic acids bearing a

• the GABAB receptor [18]. In light of the above and in connection with our interest in the chemistry of fluorinated compounds of phosphorus we report here the preparation of a series of novel (1-aminoalkyl)phosphinic acids bearing CF3 or CHF2 groups at phosphorus. Results and Discussion Research

Zirconoarylation of alkynes through p-chloranil-promoted reductive elimination of arylzirconates

• Xiaoyu Yan,
• Chao Chen and
• Chanjuan Xi

Beilstein J. Org. Chem. 2014, 10, 528–534, doi:10.3762/bjoc.10.48

• Xiaoyu Yan Chao Chen Chanjuan Xi Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology (Ministry of Education), Department of Chemistry, Tsinghua University, Beijing 100084, China State Key Laboratory of Elemento-Organic Chemistry, Nankai University, Tianjin 300071, China 10.3762

Concise, stereodivergent and highly stereoselective synthesis of cis- and trans-2-substituted 3-hydroxypiperidines – development of a phosphite-driven cyclodehydration

• Peter H. Huy,
• Julia C. Westphal and
• Ari M. P. Koskinen

Beilstein J. Org. Chem. 2014, 10, 369–383, doi:10.3762/bjoc.10.35

• –99%) (Table 2, entries 2, 11, 13 and 16). For both cyclodehydration methods (with PPh3 and P(OEt)3) neat iodine was simply added to a solution of the amino alcohols 9a–d, the phosphorus reagent and Et3N in the reaction solvent at the indicated temperature (−40 °C and −78 °C, respectively) and stirred

New hydrogen-bonding organocatalysts: Chiral cyclophosphazanes and phosphorus amides as catalysts for asymmetric Michael additions

• Helge Klare,
• Jörg M. Neudörfl and
• Bernd Goldfuss

Beilstein J. Org. Chem. 2014, 10, 224–236, doi:10.3762/bjoc.10.18

• catalysts based on rigid cis-PV-cyclodiphosphazane amides of N1,N1-dimethylcyclohexane-1,2-diamine have been developed. Employed in the asymmetric Michael addition of 2-hydroxynaphthoquinone to β-nitrostyrene, the open-chain 9-epi-aminochinchona-based phosphorus amides show a high catalytic activity with

• defined geometry. Introducing a new motif, Shea et al. have synthesized achiral tridentate (thio)phosphorus triamides and assessed their catalytic activity relative to the established (m-(CF3)2-Ph)2thiourea [18]. In the Friedel–Crafts reaction of N-methylindole with β-nitrostyrene and the Baylis–Hillman

• characteristics and the increased steric bulk of “3-D”-PV compared to “2-D” urea or squaramides make phosphorus triamides excellent candidates for asymmetric (HB) organocatalysts. However, the tetrahedral structure of PV-amides also enables a higher degree of conformational freedom combined with a less rigid

Recent applications of the divinylcyclopropane–cycloheptadiene rearrangement in organic synthesis

• Sebastian Krüger and
• Tanja Gaich

Beilstein J. Org. Chem. 2014, 10, 163–193, doi:10.3762/bjoc.10.14

• corresponding cis-divinylcyclopropane (9). Calculations have been carried out for cis-divinylheterocyclopropanes including nitrogen, oxygen, sulfur and phosphorus substitution [22], as well as cis-1,2-cyclobutanes [19][23]. Earlier calculations have been carried out for mono-heteroatom substitution in the vinyl

Charge-transfer interaction mediated organogels from 18β-glycyrrhetinic acid appended pyrene

• Jun Hu,
• Jindan Wu,
• Qian Wang and
• Yong Ju

Beilstein J. Org. Chem. 2013, 9, 2877–2885, doi:10.3762/bjoc.9.324

• Jun Hu Jindan Wu Qian Wang Yong Ju Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology, Ministry of Education, Department of Chemistry, Tsinghua University, Beijing, 100084, China, Department of Chemistry and Biochemistry, University of South Carolina, Columbia, 29208, USA

Total synthesis of the endogenous inflammation resolving lipid resolvin D2 using a common lynchpin

• John Li,
• May May Leong,
• Alastair Stewart and
• Mark A. Rizzacasa

Beilstein J. Org. Chem. 2013, 9, 2762–2766, doi:10.3762/bjoc.9.310

• using the common linchpin phosphorus ylide derived from phosphonium salt 6 [21][22] and each of the homochiral aldehydes 5 and 7 [9]. Synthesis of vinyl iodide 4 The synthesis of fragment 4 began with the production of the aldehyde 7 as shown in Scheme 2. A Wittig reaction between hemiacetal 8 [23] and

Advancements in the mechanistic understanding of the copper-catalyzed azide–alkyne cycloaddition

• Regina Berg and
• Bernd F. Straub

Beilstein J. Org. Chem. 2013, 9, 2715–2750, doi:10.3762/bjoc.9.308

• -phenanthroline derivatives is present in the reaction mixture [80]. Although the structural characteristics of the corresponding copper complexes remain elusive, these ligands are frequently applied in CuAAC reactions, especially in macromolecular chemistry [15]. Apart from N-donor ligands, the use of phosphorus

• CuAAC catalysis. With this ligand (30 mol %) and copper(I) bromide (5 mol %) the reaction of benzyl azide with phenylacetylene is completed within 10 minutes in aqueous solution at room temperature under aerobic conditions [118]. Phosphorus ligands in combination with copper(I) salts have been reported

• ). As copper(I) thiolate complexes show a high tendency to form aggregates [133][134][135][136], speciation and nuclearity of the catalytically active species remain unknown. Copper(I) complexes with phosphorus ligands, for example the commercially available air-stable salts [CuBr(PPh3)3] and {CuI[P(OEt

An efficient method for the construction of polysubstituted 4-pyridones via self-condensation of β-keto amides mediated by P₂O₅ and catalyzed by zinc bromide

• Liquan Tan,
• Peng Zhou,
• Cui Chen and
• Weibing Liu

Beilstein J. Org. Chem. 2013, 9, 2681–2687, doi:10.3762/bjoc.9.304

• Liquan Tan Peng Zhou Cui Chen Weibing Liu School of Chemistry and Life Science, Guangdong University of Petrochemical Technology, 2 Guangdu Road, Maoming 525000, China 10.3762/bjoc.9.304 Abstract A self-condensation cyclization reaction mediated by phosphorus pentoxide (P2O5) and catalyzed by

• -aryl β-keto amides as the substrates in this protocol, 4-pyridones are resulted, however, when using N-aliphatic-substituted β-keto amides as the partners of N-aryl β-keto amides under the same conditions, 2-pyridones are afforded. Keywords: β-keto amide; phosphorus pentoxide; 2-pyridones; 4-pyridones

• Ovenden used tosic acid to catalyze this transformation [20]. In this article, we report an improved efficient method for the construction of polysubstituted 4-pyridones and 2-pyridones via phosphorus pentoxide-mediated self-condensation of β-ketobutylanilides catalyzed by zinc bromide (Scheme 2). It is

IBD-mediated oxidative cyclization of pyrimidinylhydrazones and concurrent Dimroth rearrangement: Synthesis of [1,2,4]triazolo[1,5-c]pyrimidine derivatives

• Caifei Tang,
• Zhiming Li and
• Quanrui Wang

Beilstein J. Org. Chem. 2013, 9, 2629–2634, doi:10.3762/bjoc.9.298

• ]. As outlined in Scheme 1, the conversion of 4,6-dihydroxypyrimidines 1 to the dichloro derivatives 2 was accomplished by refluxing in phosphorus oxychloride for 4 h in the presence of triethylamine in yields ranging from 75 to 90% [16][17]. After screening a set of conditions, 1-(6-chloropyrimidin-4

Recent advances in transition metal-catalyzed Csp²-monofluoro-, difluoro-, perfluoromethylation and trifluoromethylthiolation

• Grégory Landelle,
• Armen Panossian,
• Sergiy Pazenok,
• Jean-Pierre Vors and
• Frédéric R. Leroux

Beilstein J. Org. Chem. 2013, 9, 2476–2536, doi:10.3762/bjoc.9.287

• trifluoromethylated arenes in good yields, and a variety of functional groups is tolerated under the mild conditions of the process. The reaction with aryl bromides or triflates is less efficient. The success of this Pd-catalyzed trifluoromethylation is due to highly hindered phosphorus ligands like BrettPhos, which

Towards stereochemical control: A short formal enantioselective total synthesis of pumiliotoxins 251D and 237A

• Jie Zhang,
• Hong-Kui Zhang and
• Pei-Qiang Huang

Beilstein J. Org. Chem. 2013, 9, 2358–2366, doi:10.3762/bjoc.9.271

• (THF) was distilled prior to use from sodium benzophenone ketyl. Dichloromethane was distilled from phosphorus pentoxide. Silica gel (zhifu, 300–400 mesh) from Yantai silica gel factory (China) was used for column chromatography, eluting (unless otherwise stated) with ethyl acetate/petroleum ether (PE

The chemistry of isoindole natural products

• Klaus Speck and
• Thomas Magauer

Beilstein J. Org. Chem. 2013, 9, 2048–2078, doi:10.3762/bjoc.9.243

• carbamate formation of the starting material. Upon exposure of 223 to phosphorus pentoxide, the desired isoindolinone 224 was formed in 75% yield. Deprotection led to lactonamycinone (214), which was the substrate for a ytterbium triflate-catalyzed glycosylation to give 215 and 217, respectively

The chemistry of amine radical cations produced by visible light photoredox catalysis

• Jie Hu,
• Jiang Wang,
• Theresa H. Nguyen and
• Nan Zheng

Beilstein J. Org. Chem. 2013, 9, 1977–2001, doi:10.3762/bjoc.9.234

• nitrogen, oxygen, or phosphorus nucleophiles In addition to carbon nucleophiles, heteronucleophiles including nitrogen, oxygen, and phosphorus are susceptible to interception of the photogenically formed iminium ions. The Xiao group developed a highly diastereroselective route to substituted

The application of a monolithic triphenylphosphine reagent for conducting Ramirez gem-dibromoolefination reactions in flow

• Kimberley A. Roper,
• Malcolm B. Berry and
• Steven V. Ley

Beilstein J. Org. Chem. 2013, 9, 1781–1790, doi:10.3762/bjoc.9.207

• polymerisation protocol consistently gave a low pressure drop across the monoliths for use in flow reactions. The monoliths were calculated to have a phosphorus loading of 1.85 mmol of phosphorus per gram, resulting in approximately 4.63 mmol of phosphorus per monolith. Loading the monolith to give the active

Synthesis and quantitative structure–activity relationship study of substituted imidazophosphor ester based tetrazolo[1,5-b]pyridazines as antinociceptive/anti-inflammatory agents

• Wafaa M. Abdou,
• Neven A. Ganoub and
• Eman Sabry

Beilstein J. Org. Chem. 2013, 9, 1730–1736, doi:10.3762/bjoc.9.199

• -diazidopyridazine reacts with nucleophilic phosphorus reagents, HE reactants, mainly in the tetrazole-form leading to the formation of tetrazolopyridazino-imidazophosphor esters or β-enaminophosphor esters. Biological assays Based on previous reports [24][25][26] that recognized the pyridazine nucleus is being

• ]pyridazine-phosphor derivatives was carried out. Thus, keeping the tetrazolopyridazine core structure intact, we studied the effect of different phosphorus-containing moieties on their antinociceptive and anti-inflammatory effects. Substrate 1 was also tested to reflect the effect of its transformations to

Organocatalyzed enantioselective desymmetrization of aziridines and epoxides

• Ping-An Wang

Beilstein J. Org. Chem. 2013, 9, 1677–1695, doi:10.3762/bjoc.9.192

• chiral complexation of the phosphorus/silicon cation, and then followed by an attack with the chloride ion in an SN2 fashion to furnish chlorohydrin enantioselectively (Figure 14). From this description, the activation of SiCl4 was depending on the formation of the chiral complexation of the phosphorus

Palladium(II)-catalyzed Heck reaction of aryl halides and arylboronic acids with olefins under mild conditions

• Tanveer Mahamadali Shaikh and
• Fung-E Hong

Beilstein J. Org. Chem. 2013, 9, 1578–1588, doi:10.3762/bjoc.9.180

• tautomerization, which generates a less stable phosphinous acid (RR'POH) species. Subsequently, its coordination to the metal center through the phosphorus atom forms a phosphinous acid–metal complex [54][55][56]. Thus, the resulting transition-metal complex might function as an active catalyst in various C–C

Homolytic substitution at phosphorus for C–P bond formation in organic synthesis

• Hideki Yorimitsu

Beilstein J. Org. Chem. 2013, 9, 1269–1277, doi:10.3762/bjoc.9.143

• review article covers emerging, powerful synthetic approaches to organophosphorus compounds by homolytic substitution at phosphorus with a carbon-centered radical. Phosphination reagents include diphosphines, chalcogenophosphines and stannylphosphines, which bear a weak P–heteroatom bond for homolysis

• reactions such as nucleophilic substitution of P–X compounds with organometallic reagents, nucleophilic substitution of alkyl halides with phosphorus nucleophiles, and nucleophilic addition to polar unsaturated bonds. Recent advances in transition-metal catalysis have realized catalytic cross-coupling

• reactions of aryl halides with H–P compounds [5][6][7] and catalytic addition to nonpolar unsaturated carbon–carbon bonds [8][9][10][11]. In the field of radical chemistry, the addition of phosphorus radicals, mainly from H–P compounds, onto carbon–carbon multiple bonds [12][13][14][15] has held a special

Amyloid-β probes: Review of structure–activity and brain-kinetics relationships

• Todd J. Eckroat,
• Abdelrahman S. Mayhoub and
• Sylvie Garneau-Tsodikova

Beilstein J. Org. Chem. 2013, 9, 1012–1044, doi:10.3762/bjoc.9.116

Methylidynetrisphosphonates: Promising C₁ building block for the design of phosphate mimetics

• Vadim D. Romanenko and
• Valery P. Kukhar

Beilstein J. Org. Chem. 2013, 9, 991–1001, doi:10.3762/bjoc.9.114

• prepared in good yield by the Arbuzov reaction of trimethylsilyl esters of trivalent phosphorus acids with the easily accessible 2,6-di-tert-butyl-4-(dichloromethyl)phenol. In the next step, the bisphosphonate 16 was oxidized with K3Fe(CN)6 into quinone methide 17 in 91% yield. Further addition of diethyl

• isosteric character relative to pyrophosphate. In particular, the P–C–P geometry (both the P–C bond distance and the P–C–P angle) is close to the geometry in the methylenebisphosphonate salts while the phosphorus–phosphorus distance is close to that observed for methylenebisphosphonates and pyrophosphate

• phosphate-based processes. In particular, some heterocyclic compounds functionalized by trisphosphonate substituents merit in-depth biological study. A further practical potential for trisphosphonate compounds is the development of new phosphorus-containing dendrimers and related species. Considerable

Preparation and ring-opening reactions of N-diphenylphosphinyl vinyl aziridines

• Ashley N. Jarvis,
• Andrew B. McLaren,
• Helen M. I. Osborn and
• Joseph Sweeney

Beilstein J. Org. Chem. 2013, 9, 852–859, doi:10.3762/bjoc.9.98

• reported direct synthesis of a vinyl aziridine bearing a phosphorus group on nitrogen [40]. Encouraged by this promising result, we next examined the scope of the reaction by using the same anion and N-Dpp imines derived from 4-bromo- and 4-fluorobenzaldehyde, furfural and 2,2-dimethylpropionaldehyde

Kinetics and mechanism of the anilinolysis of aryl phenyl isothiocyanophosphates in acetonitrile

• Hasi Rani Barai and
• Hai Whang Lee

Beilstein J. Org. Chem. 2013, 9, 615–620, doi:10.3762/bjoc.9.68

• . Keywords: anilinolysis; cross-interaction constant; deuterium kinetic isotope effects; phosphoryl transfer reaction; reactive intermediates; Y-aryl phenyl isothiocyanophosphates; Introduction The nucleophilic substitution reactions of tetracoordinate phosphorus have been studied extensively

• , experimentally and theoretically, in our lab. Two main types of displacement processes are well known in neutral phosphoryl transfer reactions: a stepwise mechanism involving a trigonal bipyramidal pentacoordinate (TBP-5C) intermediate and a concerted displacement at phosphorus through a single pentacoordinate

• TSb-H and TSf. The anilinolyses of tetracoordinate phosphorus with the Cl– leaving group have been extensively studied in this lab, and the obtained data of primary normal DKIEs involving deuterated anilines are rationalized by TSf-type in which hydrogen bonding of an amine hydrogen atom occurs on the

Asymmetric Diels–Alder reaction with >C=P– functionality of the 2-phosphaindolizine-η¹-P-aluminium(O-menthoxy) dichloride complex: experimental and theoretical results

• Rajendra K. Jangid,
• Nidhi Sogani,
• Neelima Gupta,
• Raj K. Bansal,
• Moritz von Hopffgarten and
• Gernot Frenking

Beilstein J. Org. Chem. 2013, 9, 392–400, doi:10.3762/bjoc.9.40

• extensively in the characterization of azaphospholes and their [2 + 4] cycloadducts due to their characteristic 13C–31P coupling constants [30][31][32]. In view of this, the 13C NMR spectrum of a representative product 8a was recorded. The signals of the carbon atoms directly bonded to the phosphorus atom

• formation of the cationic species 13 (Scheme 4). Furthermore, it has been established by X-ray crystal structure studies that Cr(CO)5 is coordinated to the phosphorus atom only, and no chelate complex involving the σ2,λ3-P atom and carbonyl oxygen atom is formed [27]. As reported recently, the DFT

• calculations reveal that the activation energy of the DA reaction is lowered only if the aluminium catalyst is coordinated to the phosphorus atom; when it is coordinated to the carbonyl oxygen atom, the activation energy barrier is rather high as compared to that for the DA reaction of the uncomplexed 2