Presence Of Triphenylphosphine Research Articles

Direct conversion of trimethylsilyl and tetrahydropyranyl ethers into their bromides and iodides under neutral conditions using N-bromo and N-iodosaccharins in the presence of triphenylphosphine

Trimethylsilyl and tetrahydropyranyl ethers were easily converted into their corresponding bromides and iodides with high efficiency and selectivity by N-bromo- and N-iodosaccharins in the presence of triphenylphosphine under neutral conditions. The reaction of trimethyloctyloxysilane as a model compound was studied in different solvents with different ratios of silyl ethers, triphenylphosphine and N-halosaccharin at room temperature, in order to optimize the reaction conditions.

Solvent-Free Synthesis of Novel Highly Functionalized Dihydroanthra[1,2-b]furan-6,11-dione Derivatives

A convenient and environmentally friendly solvent-free procedure has been developed to react 1,5-dihydroxyanthraquinone with dialkyl acetylenedicarboxylates in the presence of triphenylphosphine in one pot to afford novel dialkyl (E)-2-{1,5-dihydroxy-6-[3-methoxy-1-(methoxycarbonyl)-3-oxo-2-(triphenyl-λ 5-phosphanylidene)propyl]-9,10-dioxo-9,10-dihydro-2-anthracenyl}-2-butanedioate 3a–c. As a result of intramolecular nucleophilic attack at 90 °C, novel dialkyl (E)-2–{2,7-dihydroxy-3-[2-methoxy-2-oxo-1-(triphenyl-λ 5 phosphanylidene)ethyl]-6,11-dioxo-6,11-dihydroanthra[1,2-b]furan-8-yl}-2-butanedioates 4a–c were produced in good yield.

ChemInform Abstract: A Facile Route to N‐Acetyl α,β‐Unsaturated γ‐Lactam Derivatives Using Ethyl Acetamidocyanoacetate and Dialkyl Acetylenedicarboxylate in the Presence of Triphenylphosphine.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Highly efficient and selective olefination of acyl phosphonates with ethyl diazoacetate catalyzed by a cobalt(II) porphyrin complex

The cobalt(II) porphyrin complex (CoTPP) was found to be an efficient catalyst for the Wittig type olefination of acyl phosphonates with ethyl diazoacetate (EDA) in the presence of triphenylphosphine (Ph 3P). By using this one pot methodology under mild conditions, densely functionalized vinyl phosphonates were obtained in high yields and high E/ Z selectivities in relatively short reaction times. A rather broad substrate spectrum and steric influence on the reaction rate were observed.

Synthesis of Rhenium Carbonyl Complexes Bearing Substituted Pyrrolyl Ligands

The formation of rhenium carbonyl complexes incorporating substituted pyrrolyl ligands was studied: the η5 coordination mode of the pyrrolyl motif was not favored, while several bidentate monosubstituted pyrrolyl rhenium complexes were synthesized. It was shown that these species easily lose one carbonyl in refluxing THF or in the presence of triphenylphosphine.

Iridium Complexes in Olefination Reactions

Iridium complexes were found to catalyze the olefination of aldehydes in the presence of triphenylphosphine with both ethyl diazoacetate and trimethylsilyldiazomethane. Conjugated esters were obtained under mild reaction conditions at room temperature using [IrCl(cod)]2, whereas Vaska’s complex was used to synthesize terminal alkenes from trimethylsilyldiazomethane.

Investigation of electrochemically induced conjugate addition reaction: A facile approach to preparation of Schonberg adduct

Electrochemical oxidation of hydroquinone and catechols has been studied in the presence of triphenylphosphine ( 3) as a nucleophile in water/acetonitrile (40/60) solutions using cyclic voltammetry and controlled-potential coulometry. The results indicate that quinones derived from oxidation of hydroquinone or catechols, participate in a conjugate addition reaction with triphenylphosphine ( 3) via an EC mechanism, converting them to corresponding organophosphorus derivatives. In this work, we prepared C-phosphoniumquinol betaine compounds in good yields using a controlled-potential electrochemical oxidation at a carbon electrode in a divided cell.

Synthesis of polyfunctionalized alkenes and α,β-unsaturated γ-lactams from the reaction of alkyl propiolates and CH-acids such as diethyl acetamidomalonate and ethyl acetamidocyanoacetate in the presence of triphenylphosphine

Dialkyl 1-(Z)-2-(acetylamino)-2-butenedioates, 1,1-diethyl-3-alkyl (E)-(1-acetylamino)-2-propene-1,1,3-tricarboxylate, 5-ethyl-1-methyl (E)-4-(acetylamino)-4-cyano-2-pentenedioate and ethyl 1-acetyl-2-cyano-5-oxo-2,5-dihydro-1H-pyrrole-2-carboxylate were obtained from the three-component reactions between alkyl propiolates and CH-acids such as diethyl acetamidomalonate and ethyl acetamidocyanoacetate in the presence of triphenylphosphine at room temperature in dry dichloromethane.

A Convenient Approach to the Synthesis of Dialkyl 5‐Oxo‐1,2‐dihydro‐5H‐chromeno [4,3‐b]pyridine‐2,3‐dicarboxylates

Coumarin and its analogs are considered privileged scaffolds in the current synthetic and pharmacological research. The chemical behavior of enaminocarbaldehydes of the coumarin moiety under intramolecular Wittig reaction conditions in the presence of triphenylphosphine and dimethyl or diethyl acetylenedicarboxylates has been studied, resulting in the isolation of a series of dimethyl and diethyl 5‐oxo‐1,2‐dihydro‐5H‐chromeno[4,3‐b]pyridine‐2,3‐dicarboxylates in good to high yields.

<b>Synthesis and structure of a rhenium(V) complex containing a tridentate imido-coordinated Schiff base</b>

The six-coordinate complex [Re(mps)Cl2(PPh3)] (1) (H3mps = N-(2-amino-3-methylphenyl) salicylideneimine) was prepared by the reaction of [NH4][ReO4] with H3mps in the presence of triphenylphosphine and hydrochloric acid in glacial acetic acid. Crystallization from acetonitrile gave the product 1.CH3CN. The compound was characterized by spectroscopy and X-ray crystallography. The results show that the tridentate mps ligand coordinates via the doubly deprotonated 2-amino nitrogen (which is present in 1 as an imide), the neutral imino nitrogen and the phenolate oxygen. The imide and phenolate oxygen are trans to each other in a distorted octahedral geometry around the rhenium(V) centre, with the two chlorides in cis positions. KEY WORDS: Reduction of perrhenate, Rhenium(V), Imido donor atom, Crystal structure Bull. Chem. Soc. Ethiop. 2008, 22(1), 101-105.

ChemInform Abstract: Water—Acetone Media Enforced Chemoselective Synthesis of 2‐Substituted Pyrrole Stable Phosphorus Ylides from Reaction Between Pyrrole and Acetylenic Esters in the Presence of Triphenylphosphine.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

One-pot synthesis of functionalized thioureas by reaction of benzoyl isothiocyanates, secondary amines, and alkyl propiolates

An efficient one-pot synthesis of functionalized thioureas is described via three-component reaction of benzoyl isothiocyanates, secondary amines, and alkyl propiolates in the presence of triphenylphosphine (20 mol%).

Variable Bonding Modes of Pyrimidine‐2‐thione in PdII/PtII Complexes [M(η2‐N, S‐pymS)(η1‐S‐pymS)(PPh3)] and [M(η1‐S‐pymS)2(L‐L)] (L‐L = dppm, dppe)

AbstractReactions of pyrimidine‐2‐thione (HpymS) with PdII/PtIV salts in the presence of triphenyl phosphine and bis(diphenylphosphino)alkanes, Ph2P‐(CH2)m‐PPh2 (m = 1, 2) have yielded two types of complexes, viz. a) [M(η2‐N, S‐ pymS)(η1‐S‐ pymS)(PPh3)] (M = Pd, 1; Pt, 2), and (b) [M(η1‐S‐pymS)2(L‐L)] {L‐L, M = dppm (m = 1) Pd, 3; Pt, 4; dppe (m = 2), Pd, 5; Pt, 6}. Complexes have been characterized by elemental analysis (C, H, N), NMR spectroscopy (1H, 13C, 31P), and single crystal X‐ray crystallography (1, 2, 4, and 5). Complexes 1 and 2 have terminal η1‐S and chelating η2‐N, S‐modes of pymS−, while other Pd/Pt complexes have only terminal η1‐S modes. The solution state 31P NMR spectral data reveal dynamic equilibrium for the complexes 3, 5 and 6, whereas the complexes 1, 2 and 4 are static in solution state.

Improvement in the synthesis of 2-(5-amino-1,2,4-thiadiazol-3-yl)-2-(Z)-methoxyiminoacetic acid 2-benzothiazolyl thioester

2-(5-Amino-1,2,4-thiadiazol-3-yl)-2-(Z)-methoxyiminoacetic acid 2-benzothiazolyl thioester(III), an important intermediate of the fourth generation cephalosporins, was efficiently synthesized by reacting 2-(5-amino-1,2,4-thiadiazol-3-yl)-2-(Z)-methoxyiminoacetic acid (I) with 2,2′-dibenzothiazole disulfide (II) in the presence of triphenylphosphine. Effects of reaction time, temperature, solvents, catalysts and feeding molar ratio on the yield and quality of products were investigated, and an improved procedure suitable for industrial production was established. Using 1,2-dichloroethane as solvent, triphenylphosphine as reducer, and triethylamine as catalyst, n(I): n(II): n(triphenylphosphine)51.0: 1.0: 1.0, the product was obtained at room temperature in 98.1% yield. The purity of the product without further purification is 98.7% determined by HPLC method. This procedure could be a suitable alternative to the traditional processes because of its easy handling, high yield and low cost.

Heterocyclic thioamides of copper(I): Synthesis and crystal structures of copper complexes with 1,3-imidazoline-2-thiones in the presence of triphenyl phosphine

Reaction of copper(I) chloride with 1,3-imidazoline-2-thione (imzSH) in the presence of Ph 3P in 1:2:2 or 1:1:2 (M:L:PPh 3) molar ratios yielded a compound of unusual composition, [Cu 2(imzSH)(PPh 3) 4Cl 2] · CH 3OH ( 1), whose X-ray crystallography has shown that its crystals consist of four coordinated [CuCl(1κS-imzSH)(PPh 3) 2] ( 1a), and three coordinated [Cu(PPh 3) 2Cl] ( 1b) independent molecules in the same unit cell. In contrast, crystals of complexes of copper(I) bromide/iodide are formed by single molecules of [CuBr(1κS-imzSH)(PPh 3) 2] · H 2O ( 2) and [CuI(1κS-imzSH)(PPh 3) 2] ( 3), respectively, similar to molecule 1a. The related ligand, 1,3-benzimidazoline-2-thione (bzimSH) formed a complex [CuBr(1κS-bzimSH)(PPh 3) 2] · CH 3COCH 3 ( 4), similar to 2. The formation of 1a and 1b has been also revealed by NMR spectroscopy. The NMR spectra of 2– 4 also showed weak signals indicating formation of compounds similar to 1b. It reveals that the lability of the Cu–S bond varies in the order: Cl ≫ Br ∼ I. Weak interactions {e.g. C–H⋯π electrons of ring, –NH⋯halogens/oxygen, C–H⋯halogens/oxygen, π⋯π (between rings)} have played an important role in building 2D chains of complexes 1– 4.

A facile route to N-acetyl α,β-unsaturated γ-lactam derivatives using ethyl acetamidocyanoacetate and dialkyl acetylenedicarboxylate in the presence of triphenylphosphine

The three component reaction of ethyl acetamidocyanoacetate with dialkyl acetylenedicarboxylates and triphenylphosphine leads to phosphorus ylides in good yields. These ylides undergo a 1,2-proton shift, loss of triphenylphosphine, and subsequent intramolecular amidation leads to the formation of N-acetyl α,β-unsaturated γ-lactams.

Molybdenum and Tungsten Tricarbonyl Complexes of Isatin with Triphenylphosphine

Reaction of M(CO)6; M = Mo or W with isatin in the presence of triphenylphosphine in THF under reduced pressure gave the tricarbonyl derivatives complexes [M(CO)3(isatH)(PPh3)]. The two complexes were characterized by elemental analysis, infrared, mass and 1H NMR spectroscopy. The spectroscopic studies show that the two complexes exist in fac‐ and mer‐isomers in solutions through exchange the CO group and PPh3. The Uv‐Vis spectra of the complexes in different solvents were studied.

One‐Pot Synthesis of Functionalized Furamide Derivatives via a Three‐Component Reaction Between an Amine, Diketene and Dibenzoylacetylene in the Presence of Triphenylphosphine.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.

A Simple and an Efficient Method for Preparation of New Phosphorus Ylides Containing Several Functional Groups Using Aryl Thiourea

New phosphorus ylides were prepared in a convenient way using the addition of Pb(OAc)2 to aryl thiourea followed by condensation of the resulted compounds with acetylenic esters in the presence of triphenylphosphine.

Water–acetone Media Enforced Chemoselective Synthesis of 2-substituted Pyrrole Stable Phosphorus Ylides from Reaction between Pyrrole and Acetylenic Esters in the Presence of Triphenylphosphine

Pyrrole undergoes a smooth reaction with dialkyl acetylenedicarboxylates in the presence of triphenylphosphine in a mixture of water–acetone (50:50) as a solvent pathway to produce phosphorus ylides of 2-substituted pyrrole in good yield.