One–Pot Synthesis of β,γ-Unsaturated γ-Lactone Phosphorus Yildes using 2-Nitro Trans-Cinnamaldehyde and Acetylenic Esters in the Presence of Triphenylphosphine

Abstract

Three-component reaction of triphenylphosphine and 2-nitro trans-cinnamaldehyde with dialkyl acetylenedicarboxylate leads to β,γ-unsaturated γ-lactone phosphorus ylides in moderate yields. The reactions of 2-nitro trans-cinnamaldehyde with alkyl propiolates in the presence of triphenylphosphine produce 2H-pyran derivatives in moderate yields without the formation of any γ-lactone derivatives.     

PERI-INTERACTIONS IN NAPHTHALENES, 21. SUBSTITUENT EFFECTS IN (8-DIMETHYLAMINO-NAPHTH-1-YL)- AND [2-DIMETHYLAMINO-METHYL)PHENYL] - PHOSPHINES ON THE 31P-NMR SIGNAL POSITIONS

Abstract

Contrary to claims in the literature, the ³¹P NMR signal positions of ortho-dimethylaminomethyl-substituted triarylphosphines do not provide evidence for hypercoordination at phosphorus; the observed highfield shifts relative to triphenylphosphine are rather due to the ortho-effect. In (8-dimethylamino-naphth-1-yl)phosphines, the signal positions similar to that of triphenylphosphine are the result of the highfield ortho-effect and a lowfield peri-substituent effect of about the same magnitude whose nature remains to be explored.     

SYNTHESIS OF SPIRO [1,3-BENZODIOXOLE-2,4′-(3′H) QUINAZOLINES]

Abstract

In the present investigation, the authors could obtain a new series of spiranes (1) through the reaction of the high potential quinone tetrachloro-o-benzoquinone with 2-aryl-3-phenyl-3H-quinazoline-4-thiones. Thus, 2,3-diphenyl- (2a), 2-p-tolyl-3-phenyl- (2b) and 2-p-anisyl-3-phenyl- (2c)-3H-quinazoline-4-thiones react readily with tetrachloro-o-benzoquinone, in boiling toluene, to give the corresponding spiro-1,3-benzodioxole-2,4′-(3′H)-quinazolines (1a-c), respectively.     

New Application of N-Halosuccinimide/PPh3 for the Halogenation of Propargyl Alcohols to Haloallenes

An efficient and convenient new method has been developed for the preparation of haloallenes from propargyl alcohols by a reagent combination of N-halosuccinimide and triphenylphosphine. Chloroallenes 2 and bromoallenes 3 were obtained exclusively in moderate to good yields with regioselectivity.     

2-Phosphaindolizines

Abstract

An overview of 2-phosphaindolizines, i.e. 1,3-azaphospholo[1,5-a]pyridines along with their 1-aza-, 3-aza- and 1,3-diaza analogues has been presented. It includes their methods of syntheses, characterization and reactions. Under reactions, electrophilic substitutions, N-alkylation, Diels-Alder (DA) reactions with the >C=P- functionality in the absence of the catalyst and also in the presence of the catalyst, other 1,2-additions across the >C=P- functionality, cheletropic cycloaddition of tetrachloro-o-benzoquinone (TCQ) with the phosphorus atom and co-ordination with the metal pentacarbonyls and other derivatives have been described.     

Addition of H2-D2 Mixtures to 2-Butyne and Norbornene Catalyzed by Solutions of Chlorotris(triphenylphosphine)rhodium(I), Hydridocarbonyltris(triphenylphosphine)rhodium(I), and Hydridotetrakis(5-phenyl-5-H-dibenzophosphole)rhodium(I)

The use of H₂/D₂ mixtures in place of H₂ as a probe of the mechanisms of hydrogenation is explored using the catalyst precursors chlorotris(triphenylphosphine)rhodium(I) (I), hydridocarbonyltris(triphenylphosphine) rhodium(I) (II), and hydridotetrakis(5-phenyl-5-H-dibenzophosphole)rhodium (I) (III). Benzene solutions of these complexes catalyze the H₂-D₂ equilibration, the relative rates decreasing in the order III > II > I. The accepted mechanism of hydrogenation catalyzed by I does not accommodate the observed isotopic exchange, which is inhibited by added acids (trifluoroethanol, 1,3,4-trichlorophenol) and accelerated by small amounts of triethylamine; the formation of hydridotris(triphenylphosphine)rhodium(I) is implicated. The H₂ and D₂ added to an unsaturated hydrocarbon is randomized with complexes II and III as the catalyst, whereas the molecular identity of H₂ and D₂ is retained if the dihydrido is the catalyst. __________ From Kinetika i Kataliz, Vol. 46, No. 6, 2005, pp. 891–900. Original English Text Copyright ? 2005 by Lin, Siegel. This article was submitted by the authors in English. The experiments were conducted at the University of Arkansas.     

A FACILE SYNTHESIS OF DIETHYL 1- ISOTHIOCYANO)ALKYLPHOSPHONATES[1]

Abstract

Novel, diethyl 1-(isothiocyano)alkylphosphonates 3 have been efficiently synthesized via a one-pot reaction of diethyl 1-azidoalkylphosphonates 1 with triphenylphosphine, followed by in situ transformation of thus formed phosphazenes 2 with carbon disulfide. Application of the title compounds in the synthesis of diethyl (N-phenylthioureido)- and (benzothiazol-2-ylamino)methylphosphonates was also described.     

New Synthesis of Acetaminophen Derivatives Containing a Phosphorus Atom

Two derivatives of acetaminophen have been efficiently prepared from 4-aminophenol via a two-step procedure involving acetylation of OH and NH ₂ groups and then the reaction of the acetylated compounds with diakyl acetylenedicarboxylate in the presence of triphenylphosphine. The products were obtained in good yields.     

A RAPID AND FACILE CONVERSION OF PRIMARY AMIDES AND ALDOXIMES TO NITRILES AND KETOXIMES TO AMIDES WITH TRIPHENYLPHOSPHINE AND N-CHLOROSUCCINIMIDE

ABSTRACT

Primary amides and aldoximes are easily converted to their corresponding nitriles using a mixture of triphenylphosphine and N-chlorosuccinimide in dichloromethane at room temperature. The reaction of aldoximes occurs almost immediately and primary amides in 0.5?h by this method. By this procedure secondary amides are produced by Beckmann rearrangement of ketoximes.     

An Improved Synthesis of Per(6-Deoxyhalo) Cyclodextrins Using N-Halosuccinimides —Triphenylphosphine in Dimethylformamide

Abstract

Per(6-deoxy-6-halo) cyclodextrins (bromo, chloro or iodo) have been prepared in excellent yield and high selectivity by treatment of the native cyclodextrins with the corresponding N-halosuccinimide and triphenylphosphine in N,N-dimethylformamide.     

Synthesis of 4,5-Dialkyl 1-Isopropyl 3-Isopropoxy1 H -Pyrazole-1,4,5-tricarboxylate by Using Mitsunobu Chemistry

4,5-dialkyl 1-isopropyl 3-isopropoxy-1H-pyrazole-1,4,5-tricarboxylate was obtained in an excellent yield from the reaction of dialkyl acetylenedicarboxylates and diisopropyl azodicarboxylate in the presence of triphenylphosphine in dry dichloromethane. This reaction provides a useful synthetic route to highly functionalized pyrazoles.     

Selective Monoesterification of Unprotected Mono and Disaccharides

Abstract

Under mild conditions, treatment of unprotected methyl-α-D-glucopyranoside, N-acetylglucosamine and maltose with triphenylphosphine, diethylazodicarboxylate and equimolar amount of various carboxylic acids allowed regioselective 6-O-esterifications (6′-O for maltose) of the carbohydrate without esterification of other hydroxyl groups. This reaction found an application in the synthesis of liposoluble, labelled sugars and hydrosoluble polymers.     

HIGH YIELD SYNTHESIS OF α-ALKOXYPHOSPHONIUM SALTS AND α-ALKOXYPHOSPHONATES

Abstract

The recent work of Ley et al. ¹ on α-alkoxyphosphorane compounds from cyclic enolethers has prompted us to report our findings in this area. In addition to cyclic enol ethers we have studied the acyclic case as well as the use of phosphite in place of triphenylphosphine. Using this approach we have prepared alkoxy-as well as 5-and 6-membered oxyheterocyclic phosphonium salts and phosphonates in high yield.     

Reaction of N-sulfinyltrifluoromethanesulfonamide with triphenylphosphine and triphenylphosphine oxide

The reaction of N-sulfinyltrifluoromethanesulfonamide with triphenylphosphine and triphenylphosphine oxide or of trifluoromethanesulfonamide with dichloro(triphenyl)phosphorane leads to trifluoro-N-(triphenyl-λ⁵-phosphanylidene)methanesulfonamide, which is hydrolyzed to trifluoromethanesulfonamide and triphenylphosphine oxide via the intermediate trifluoro-N-[hydroxy(triphenyl)phosphoranyl]methanesulfonamide.     

Umsetzung von 1,5-Dimethyl-2,3,3,4-tetrachlor-1,5,2,4-diazadiphosphorinan-6-on mit Anilinderivaten,Heptamethyldisilazan und tert.-Butylamin: Oxidative Addition von Tetrachlor-o-benzochinon an einige P(III)-haltige Produkte

The reaction of the title compound 1 with the p-R-aniline derivatives (R═H, F, OCH₃, NO₂, and NH₂) led to the formation of the aza-2σ³,4σ³-diphosphetidines 2a– 2e, whereas 2-trimethylsiloxyaniline furnished the azadiphosphetidine 2f. The reaction of the sterically crowded 2,6-dimethylaniline with 1 furnished the disubstituted derivative 3. The tricyclic compound 5 was formed during the reaction of 1,2-phenylenediamine with 1. Heptamethyldisilazane formed the aza-2σ ³ ,4σ ³ -diphosphetidine 6 on reaction with 1. The bulkier tert.-butylamine formed with 1 a mixture of the aza-2,4-diphosphetidine 7a and the disubstituted derivative 7b, which could not be separated. The reaction of 2b and 6 with tetrachloro-o-benzoquinone resulted in the formation of the bis-spirophosphoranes 8 and 9b, respectively. The formation of the monospirophosphorane 9a was observed in the ³¹P NMR spectrum. The characterization of compounds is based in particular on NMR investigations (¹H, ¹³C, ³¹P). 2a was characterized by a single-crystal X-ray structure analysis. The dimethylurea fragment is planar; the four-membered ring is folded about the P···P vector by 38.7°.     

Synthesis and Crystal Structure of the Copper(I) Chloride Complex with 4,5(4-Pyridylethylene)dithio-1,3-dithiol-2-thione and Triphenylphosphine

The synthesis of a heteroligand complex of CuCl with triphenylphosphine and 5-pyridine-4-yl-5,6-dihydro-[1,3]dithiolo[4,5-b][1,4]dithiine-2-thione (L) of composition { [CuCl(PPh₃)(L)](CH₃ CN)}₂ (I) is described. The crystals of complex I are triclinic: space group , a = 8.928(2) Å, b = 13.872(3) Å, c = 14.470(3) Å, α = 72.89(3)°, β = 88.41(3)°, γ = 77.02(3)°, and Z = 2. The Cu(1) atom has a quasi-tetrahedral environment including the phosphorus atom of the triphenylphosphine molecule, nitrogen atom of the pyridyl radical of molecule L, and two bridging chloride ions. The fact that noncoordinated sulfur atoms are present can be used for the further interaction of complex I with soft Lewis acids.__________Translated from Koordinatsionnaya Khimiya, Vol. 31, No. 6, 2005, pp. 462–465.Original Russian Text Copyright © 2005 by Koshevaya, Starodub.     

Theoretical study of the mechanism of stable phosphorus ylides derived from 2-aminothiophenol in the presence of different dialkyl acetyelenedicarboxylates

A stepwise reaction mechanism between triphenylphosphine 1 and dialkyl acetylenedicarboxylates 2 in the presence of a SH-acid, such as 2-aminothiophenol 3, has been investigated theoretically with B3LYP method using 6-311++G(d,p) basis set. Potential energies of all structures participating along the reaction path have been evaluated. For all the reactions investigated, the first step was recognized to be the rate-determining step. Quantum mechanical calculations clarified the existence of reaction product as a mixture of two E- or Z-geometrical isomers, and indicate which one of them represents the major form. The effect of subsituated alkyl groups on the potential energy surfaces was investigated. Also, the natural bond orbital method was applied for better understanding the molecular interactions.     

2-氨基噻吩并[2,3-d]嘧啶-4(3H)-酮衍生物的合成

丁醛(1)、氰乙酸乙酯、硫磺在三乙胺作用下制得2-氨基-4-乙基噻吩-3-羧酸乙酯(2), 2再与三苯基膦、六氯乙烷及三乙胺反应, 以84%的产率得到膦亚胺3. 应用膦亚胺3与芳基异氰酸酯的氮杂Wittig反应, 生成的碳二亚胺4, 再与仲胺作用得到中间体5, 而后在醇钠的催化下关环制得2-二烷氨基噻吩并[2,3-d]嘧啶-4(3H)-酮衍生物6, 产率为58%～82%.     

Simple Synthesis of Stable Phosphorus Ylides Derived from Imidazolidine-2-Thione. Efficient One-Pot Synthesis of α-Amino Esters with β-Phosphorus Substituents

Crystalline phosphorus ylides are obtained in nearly quantitative yields from the addition reaction between triphenylphosphine, dialkyl acetylenedicarboxylates, and imidazolidine-2-thione. A dynamic NMR effect is observed in the ¹ H NMR spectrum of the stabilized ylide obtained from dimethyl acetylenedicarboxylate (Δ G ^≠ = 66.6 kJmol^?1 ) and is attributed to restricted rotation around the carbon–carbon partial double bond resulting from the conjugation of the ylide moiety with the adjacent carbonyl group.     

Application of Dichlorovinyl Xyloside for the Novel Synthesis of 2,3,4‐Tri‐O‐methyl‐D‐xylono‐1,5‐lactone

A novel synthesis of 2,3,4‐tri‐O‐methyl‐D‐xylopyranose, 4, and its oxidation product 2,3,4‐tri‐O‐methyl‐D‐xylono‐1,5‐lactone, 5, are reported. The new synthesis applies a regioselective Wittig‐like reaction of tetra-O-acetyl-D-xylopyranase, 1, with triphenylphosphine and carbon tetrachloride to yield an O‐dichlorovinyl xyloside protected at C‐1, 2. The protecting group facilitates the permethylation of xylose and is removed under the methylation conditions, to yield tetra-O-acetyl-D-xylopyranase, 3. The anomeric methyl group was removed under mildly acidic conditions to give 2,3,4‐tri‐O‐methyl‐D‐xylopyranose, 4, in good yield. Compound 4 was oxidized using pyridinium chlorochromate to give the title compound, 5, in 95% yield.