Synthetic Applications of Phosphonium Diylides

Abstract

Phosphonium diylides 1 react with electrophiles leading to new monoylides which permit., by a Wittig reaction, the E stereoselective synthesis of various di- or tri-substituted α,β-unsaturated functionalized compounds.     

Pyrolysis of Amino Acid Derived Stabilised Ylides as a Route to Chiral Acetylenic Amines and Amino Acids and Gaba Analogues

Abstract

We recently reported the pyrolysis of stabilised ylides as a method for overall conversion of carboxylic acids to homologous acetylenic esters and terminal alkynes.^1,2 This has now been applied successfully to amino acids. A wide range of alkoxycarbonyl protected amino acids have been converted to the stable crystalline ylides 1. These have been fully characterised, and upon FVP, eliminate Ph₃PO to afford the protected acetylenic amino acids 2 in good yield and without significant racemisation. Subsequent reactions of these extremely versatile intermediates have been used to gain access to a wide variety of chiral amine and amino acids of great interest as potential selective enzyme inhibitors and components for modified peptide structures.     

C60-吡咯烷衍生物的合成及非线性光学性质的研究

通过富勒烯C₆₀与肌氨酸和有机醛化合物的1,3-偶极环加成反应, 获得了九种含不同有机功能基团的C₆₀吡咯烷衍生物1～9, 用¹H NMR, ¹³C NMR, FTIR, UV-vis和FAB-MS进行了结构表征; 利用皮秒激光光源, 采用z扫描技术测定了分子的三阶非线性超极化率γ⁽³⁾, 结果显示: 化合物3 (γ⁽³⁾＝4.14×10^－33 esu)具有最大的三阶非线性光学系数, 说明增加噻吩共轭链的长度, 使三阶非线性活性增加; 对具有相同共轭链的C₆₀-噻吩吡咯烷衍生物(2, 5, 1和4), 吸电子取代基减小了三阶光学非线性活性, 给电子基增大了三阶光学非线性活性; 同时发现喹啉环2-位键联(7)比4-位(8)有更好的三阶光学非线性活性.     

Solution and Solid State Structure of Highly Delocalised 5- Triphenylphosphoranylidenecyclopen Tene-3,4-Diones

The fully assigned ¹³C NMR spectra of the cyclic ylides 4 and 5 show that the C-1-C-2 bond is very strongly polarised consistent with substantial delocalisation of the ylide negative charge on to C-2. The X-ray structure of 5 confirms the occurrence of extensive delocalisation involving a significant contribution from up to six separate resonance forms.     

A Facile,One-Pot Synthesis of Azoic Compounds and Anthraquinone Derivatives Containing Dialkyl Phosphoryl Moieties in Multicomponent Reactions

Protonation of the reactive 1:1 intermediates produced in the reactions between triphenylphosphine and dialkyl acetylenedicarboxylates by 1-amino-anthraquinone or 1,5-diphenylcarbazone as a core dye leads to vinyl phosphonium salts, which undergo Michael addition with conjugate base of NH compounds to produce stable phosphorus ylides as novel dyes in fairly good yields. These ylides can exist in two geometrical isomers (Z) and (E) for 3, because the negative charge of the ylide moiety of these compounds are strongly conjugated with the adjacent carbonyl group. Rotation around the carbon–carbon double bond is slow in the (Z) and (E) geometrical isomers on the NMR time scale at ambient temperature. These compounds are assigned by their IR, ¹H, ¹³C NMR spectral data as well as their mass spectroscopic data.     

Dipiiosphoniomethanes with Hydrogen Atom,OH- And SH-Groups at Phosphorus

Abstract

Recently it has been shown that the interaction of equimolar amount of HHlg witii phosphinosubstituted ylides (I) and phosphoryl- and thiophosphorylsubstituted ylides (II) leads to monoprotonation products: at the carbon or phosphorus of (I) and at the carbon or oxygen (sulfur) of (II)¹. We have found that products of double protonation, diphosphoniomethanes with P-H (III) and P-OH (IV) bonds respectively, are formed by the action of excess acid (HSO₃F, HHlg).     

Synthesis and characterization of a [5.5]paracyclophane‐containing silicon by NMR spectroscopy and X‐ray crystallography

The synthesis and characterization of 1,3,10,12‐tetraoxo‐2,11‐(diphenylsilylene)[5.5]par‐acyclophane obtained by reaction of 1,4‐benzenedimethanol and dichlorodiphenylsilane is reported. The structure was established by mass spectrometry; ¹H, ¹³C, and ²⁹Si NMR; and X‐ray diffraction analysis. © 1999 John Wiley & Sons, Inc. Heteroatom Chem 10: 351–354, 1999     

New and Stereospecific Synthesis of α-Ethylenic Ketones

Abstract

H. Kise et al¹ have shown that the reaction of β-propiolactones 1 with ylides 2 give phosphonium carboxylate betaïne 3. We now report that, carried out under different conditions, reaction of lactones 1 with the same ylides proceeds through pathway (b). Thermolysis of 4 affords α-ethylenic ketones 5. The mecanism of this new extrusion reaction of triphenylphosphine oxyde probably involves the generation of an oxaphosphene as an intermediate.     

Formation of a New Zwitterionic Phosphorus Compound using Bun 3P and COS

Abstract

We have recently reported the use of the crystalline tri-n-butylphosphine-carbon disulfide adduct to form a variety of heterocyclic compounds including dithiole-containing ylides,¹ 2-alkylidene- 1.3-dithiolanes,² and dihydrotetrathiafulvalenes³. In particular reaction with DMAD gave the dithiole-containing ylide shown¹. We now describe the corresponding reaction of triburylphosphine and carbonyl sulfide, COS, with a variety of unsaturated systems which generally takes a completely different course as shown for the example of DMAD below. The structure of the unusual zwitterionic product has been confirmed by X-ray diffraction and is shown.     

Synthesis,spectroscopic and X-ray structural studies of silver(I) complexes of α-keto stabilized phosphorus ylides

Reactions between AgX (X = OTf, NO₃) and ylides of the type Ph₃P = CHC(O)C₆H₄-4-R (R = F, Br, OMe) in molar ratio 1 : 2 lead to complexes [Ag{CH(PPh₃)C(O)C₆H₄-4-R}]X (1–4); X-ray structure determinations have been carried out on 4. The IR and NMR data of the products formed by reaction of Ag(I) with the ylides are consistent with C-bounded ylides. Analytical data indicate 1 : 2 stoichiometry between the ylide and Ag(I) in the products. The molar conductivities of these complexes are within the range for 1 : 1 electrolytes. Crystallographic data for 4 are: crystal system, triclinic; space group, P 1, a = 12.1151(4), b = 13.8989(5), c = 15.4855(5) Å, β = 102.676(3)°, V = 2477.82(15) ų, Z = 2.     

An Efficient One-Pot Synthesis of 2,3-Dialkyl-1,1-Diethyl-1-(Acetylamino)-3-(1,1,1-Triphenylphosphanilidene)-1,1,2,3-Propanetetracarboxylates and Their Temperature-Dependent NMR Spectra

Abstract

Stable crystalline phosphorus ylides of 1,1-diethyl 2,3-dimethyl 1-(acetylamino)-3-(1,1,1-triphenylphosphanilidine)-1,1,2,3-propanetetracarboxylates were obtained in excellent yields from the 1:1:1 addition reaction between triphenylphosphine and dialkyl acetylenedicarboxylates in the presence of diethyl acetamidomalonate as a CH-acid. These stable ylides exist in solution as a mixture of two geometrical isomers (E and Z) as a result of restricted rotation around the carbon–carbon partial double bond resulting from conjugation of the ylide moiety with the adjacent carbonyl group on the nuclear magnetic resonance (NMR) time scale at ambient temperature. The dynamic effects in the ylide moieties were investigated by ¹H NMR spectra.

Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.     

Synthesis of New Cheral Macrocyclic Tetraoxo Polyamines Containing Pyridine Ring and Functional Arms

Seven new chiral macrocyclic tetraoxo polyamines containing pyridine ring and functional arms derived from L-histidine, L-alanine, L-leucine and L-phenylalanine, respectively, have been synthesized and characterized by MS, ¹H NMR and elemental analysis.     

Studies on Phosphonium Ylides-XXIII: The Behavior of Active and Stabilized Phosphonium Ylides Towards Thiohydantoins

Thiohydantoin 1 reacts with 2-oxovinylidenetriphenylphosphorane (2) to give 1-methyl-2-thioxo-6-(triphenyl-λ⁵-phosphoranylidene)-hexahydro-furo[2,3-d]imidazol-5-one (5). On the other hand, when 1 reacts with phosphorus ylides 3a–d, the respective olefinic adducts 6a, 6b, 8, and the dimeric product 7 were obtained together with triphenyl-phosphine oxide. Moreover, the application of reagent 4 on 1 renders the new product 4-methyl-2,3-diphenyl-2,3,4,6-tetrahydro-1-oxa-1,3,4,6-tetra-azapentalene-5-thione. Mechanisms accounting for the formation of the products are presented based on analytical and spectroscopic data.     

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.     

Amidrazones. 6 . Synthesis of 1,2,4-thiadiazoles by thermolysis of N3-thiocarbamoylamidrazone ylides

Reaction of N³-unsubstituted amidrazone ylides ( 1a and 1b ) with alkyl or aryl isothiocyanates gives N³-thiocarbamoylamidrazone ylides ( 2 ). Thermolysis of 2 gives 3-alkyl(or aryl)-5-alkyl(or aryl)amino-1,2,4-thiadiazoles ( 3a-i ).     

A Simple Synthesis of Stable Phosphorus Ylides from Indole and Some of Its Derivatives

Stable crystalline phosphorus ylides were obtained in excellent yields from the 1:1:1 addition reaction between triphenylphosphine and dialkyl acetylenedicarboxylates in the presence of strong NH acids, such as indole and 2-methyl indole, 3-methyl indole, and 5-boromo indole. These stable ylides exist in a solution as a mixture of two geometrical isomers as a result of the restricted rotation around the carbon–carbon partial double bond resulting from the conjugation of the ylide moiety with the adjacent carbonyl group.     

Synthesis of Amino Acid Derived Cyclic Phosphorus Ylides

Abstract

We recently reported the thermal elimination of Ph₃PO from suitably protected aminoacyl ylides 1 as a route to acetylenic amino acid analogues 2. Pyrolysis of ylides such as 3 with a free amino group takes a different course. Ethanol is eliminated to give the c h i d cyclic ylides 4 which can be viewed as 3-triphenylphosphoranylidene tetramic acids. Specific examples prepared include 4 (R = Me, Pri), the parent compound 5 (from glycine) and the six-membered ring compound 6 (from p-alanine). Using a similar approach, bicyclic ylides such as 7 (from proline) can be prepared. In the case of the glutamate derived ylide 8, thermolysis initially gives a mixturc of 9 and 10 but these both cyclise to the bicyclic product 11 with time. The structure and reactivity of these interesting cyclic ylides are now being examined.     

New heteroorganic betaines containing the (+)E15—C—E14—X(–) and (+)E15—C—E14(–) structural fragments (E15 = P,As; E14 = Si,Ge, Sn; X = C,S, O,NR)

The review surveys the data on the reactions of phosphorus and arsenic ylides with compounds containing E=X bonds (E = C, Si, Ge, or Sn; X = C or S), cyclic oligomers (R₂ES)_n (n = 2 or 3), and heavier analogs of carbenes. These reactions give rise to two new classes of heteroorganic betaines containing the ⁽⁺⁾E¹⁵—C—E¹⁴—X^(–) (I) and ⁽⁺⁾E¹⁵—C—E^14(–) (II) (E¹⁵ = P or As; E¹⁴ = Si, Ge, or Sn; X = C or S) structural fragments. Procedures for the synthesis of these compounds, their reactivities, the X-ray diffraction structures, and the electronic structures established by high-level quantum-chemical calculations are considered in detail. The carbon analogs of betaines of type I, viz., compounds bearing the ⁽⁺⁾P—C—C—X^(–) fragment (III), are also discussed. The latter were long considered as possible intermediates in the reactions of compounds containing the polar C=X bond (X = C, O, S, NR, etc.) with phosphorus ylides (classical Wittig and Corey—Chaykovsky reactions and related processes).     

One-Pot Synthesis of Stable Phosphorus Ylides Using CH-Acid Compounds

Stable crystalline phosphorus ylides were obtained in excellent yields from the 1:1:1 addition reaction between triphenylphosphine and di-tert-butyl acetylendicarboxylate, in the presence of antron, dimedone, indandion, and 3,5-dimethylbarbituric acid. These stable ylides exist in a solution as a mixture of two geometrical isomers as a result of restricted rotation around the carbon-carbon partial double bond resulting from conjugation of the ylide moiety with the adjacent carbonyl group.     

211At and 125I-Labeling of (Hetero)Aryliodonium Ylides: Astatine Wins Again

Despite the growing interest in radioiodine and ²¹¹At-labeled radiopharmaceuticals, the search for radiolabeling reactions has been somewhat neglected, resulting in a limited number of available radiosynthetic strategies. Herein we report a comparative study of nucleophilic ¹²⁵I and ²¹¹At-labeling of aryliodonium ylides. Whereas radioiodination efficiency was low, ²¹¹At-labeling performed efficiently on a broad scope of precursors. The most activated aryliodonium ylides led rapidly to quantitative reactions at room temperature in acetonitrile. For deactivated precursors, heating up to 90 °C in glyme and addition of 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) as radical scavenger appeared essential to avoid precursor degradation and to achieve high radiochemical yields and molar activity. The approach was applied successfully to the preparation of 4-[²¹¹At]astatophenylalanine (4-APA), an amino acid derivative increasingly studied as radiotherapeutic drug for cancers. This validated aryliodonium ylides as a valuable tool for nucleophilic ²¹¹At-labeling and will complement the short but now growing list of available astatination reactions.