Metallkomplexe mit biologisch wichtigen Liganden. LXXXII. Triphenylphosphan-Molybdän-, Wolfram-, Ruthenium- und Iridium-Komplexe mit N-acylierten α-Aminocarboxylaten

Metal Complexes of Biological Important Ligands. LXXXII. Triphenylphosphine Molybdenum, Tungsten, Ruthenium, and Iridium Complexes of N-Acyl-α-Aminocarboxylates The reactions of the hydrido complexes RuHCl(CO) · (PPh₃)₃, RuH₂(PPh₃)₄ and IrH₃(PPh₃)₃ with N-acyl-α-aminocarboxylates give the carboxylate complexes RuCl(O₂CCHRNHCOR′)(CO)(PPh₃)₂ ( 1–3 ), RuH(O₂CCHRNHCOR′)(PPh₃)₃ ( 4–6 ) and IrH₂(O₂CCH₂NHCOPh)(PPh₃)₃ ( 7 ). The structure of RuCl · (O₂CCHNHCOPh)(CO)(PPh₃)₂ ( 1 ) has been determined by x-ray diffraction. The triphenylphosphine complexes MBr · (O₂CCH₂NHCOR)(CO)₂(PPh₃)₂ (M = Mo, W) ( 8–12 ) and Mo(O₂CCHRNHCOR′)₂(CO)₂(PPh₃)₂ ( 13–17 ) are formed from MBr₂(CO)₂(PPh₃)₂ (M = Mo, W) with one or two equivalents of N-acyl-a-aminoacidates, respectively.     

One‐Pot Synthesis of Tetraalkyl Benzene‐1,2,3,5‐tetracarboxylates from a Four‐Component Reaction of Alkyl Propiolates and Alkyl 2‐Nitroethanoates Promoted by Ph3P

Alkyl 2‐nitroethanoates react with alkyl propiolates in the presence of triphenylphosphine (Ph₃P) in a mechanistically unprecedented reaction to afford tetraalkyl benzene‐1,2,3,5‐tetracarboxylates in moderate yields (36–42%).     

Synthesis and Dynamic NMR Spectroscopic Study of Dialkyl 4-Ethoxy-1-(1-naphthyl)-5-oxo-4,5-dihydro-1<Emphasis Type="Italic">H</Emphasis>-pyrrole-2,3-dicarboxylates

Summary. Protonation of the reactive 1:1 intermediate produced in the reaction between triphenylphosphine and dialkyl acetylenedicarboxylates with ethyl 2-(1-naphthylamino)-2-oxoacetate, leads to a vinylphosphonium salt, which undergoes intramolecular Wittig reaction to produce dialkyl 4-ethoxy-1-(1-naphthyl)-5-oxo-4,5-dihydro-1H-pyrrole-2,3-dicarboxylates in excellent yields. A dynamic NMR effect is observed in the ¹H NMR spectra of the title compounds as a result of restricted rotation around the single bond linking the naphthalene moiety and the heterocyclic system, which is attributed to the peri interaction between the pyrrole residue and the peri CH group. The free energy of activation (G ) for this process is 58±2kJmol^–1.Received December 6, 2002; accepted December 11, 2002 Published online June 12, 2003     

The recovery of gallic acid with triphenylphosphine oxide in different kind of solvents

In this study, gallic acid was separated by triphenylphosphine oxide in the presence of conventional solvents. Triphenylphosphine oxide is an organophosphorus extractant and highly selective towards carboxylic acids. Reactive extraction results were compared with physical extraction results. The extraction efficiencies reached up to 61, 76, 86, 67, and 84% in the presence of triphenylphosphine oxide with oleyl alcohol, dimethyl adipate, isobutanol, methyl isopropyl ketone, and methyl ethyl ketone, respectively. Further, the number of theoretical units and the solvent to feed ratio were calculated for the practical design of a liquid-liquid extraction column. Roughly 2 to 4 theoretical units were calculated to meet the targeted extraction efficiencies. This study is the first to investigate the reactive extraction of gallic acid by triphenylphosphine oxide, and include fundamental information for the recovery of gallic acid.     

Proton transfer process in synthesis of 3-acetyl-4-(substituted ethylenyl)coumarins and chromeno[3,4-c]pyridines

The triphenylphosphine mediated reactions of electron-deficient carbon-carbon triple bonds with 3-acetylcoumarins in dichloromethane afford functionalized 3-acetyl-4-(substituted ethylenyl)coumarins. Also, triphenylphosphine-catalyzed three-component cascade annulation reactions of 3-acetylcoumarins, activated acetylenic compounds, and hydrazines or amines provide a straightforward access to 3,5-dihydro-2H-chromeno[3,4-c]pyridine-1,2-dicarboxylates. In these strategies, the main step to the target products is proton transfer process. All products were obtained in good to high yields.     

四(三苯基氧化膦)二氯稀土(Ⅲ)-三氯化铜(Ⅱ)配合物的合成和谱学性质

合成了通式为[LnCl_2(Ph_aPO)_4][CuCl_3](Ln=La,Ce,Pr,Nd,Sm,Eu,Gd,Tb,Dy,Ho,Er,Y)的12种新配合物,X射线衍射结构分析证实[GdCl_2(Ph_2PO)_4][CuCl_3]中Gd(Ⅲ)为六配位畸变八面体形,Cu(Ⅱ)为三配位平面三角形.测定了所有配合物的红外光谱、~(31)P NMR和Cu(Ⅱ)的顺磁共振谱,并对[LnCl_2(Ph_3PO)_4][CuCl_3]的生成进行了讨论.     

Furanyl Alcohols as Alkylating Reagents in Friedel–Crafts Reaction of Arenes

Furanyl alcohols react with arenes by a variant of the Friedel–Crafts reaction to give benzyl furans with fairly satisfying yields. The reaction is mediated by Tf₂O and occurs with reduced times in the presence of Ph₃PO. Some prepared compounds exhibit a lignan‐like backbone.     

A mild and efficient method for bromination of alcohols using α,α-dibromo-β-dicarbonyl compounds as halogen sources

Exploration of α,α-dibromo-β-dicarbonyl compounds as novel bromine agents for the conversion of alcohols to alkyl bromides under neutral conditions has been achieved. This method can be used for acid-sensitive substrates and allows the bromination of various primary and secondary alcohols to proceed at room temperature within a very short period of time.     

Stable 1,6-Diionic Phosphorus Betaines Derived from Electron-Deficient Acetylenic Compounds

The addition of triphenylphosphine to methyl propiolate, ethyl propiolate, or ethynyl methyl ketone in the presence of a strong NH-acid, such as 5-nitro-2,4-dihydro-3 H -1,2,4-triazol-3-one, leads to stable 1,6-diionic organophosphorus compounds in excellent yields.     

An efficient synthesis of substituted alkyl acrylates using α-keto amides

The addition of α-keto amides as a NH-acid to alkyl propiolates and dialkyl acetylenedicarboxylates in the presence of a catalytic amount of triphenylphosphine gives the corresponding substituted alkyl acrylates.