Synthesis of aromatic amine phosphonato ester derivatives from the stereoselective reaction between triphenyl phosphite and dimethyl acetylenedicarboxylate in the presence of derivatives of aromatic amines

An efficient synthesis of functionalized β-amino- and β-hydrazinoalkylphosphonates by three-component reaction between trialkyl phosphites, dialkyl acetylenedicarboxylates and aromatic amines or hydrazines

Three-component reaction between trialkyl phosphites, dialkyl acetylenedicarboxylates and aromatic amines afforded β-aminoalkylphosphonate derivatives. Similar reaction between trialkyl phosphites, dialkyl acetylenedicarboxylates and dinitrophenylhydrazine afforded β-hydrazinooalkylphosphonate derivatives. This method includes both the C-N and C-P bond formation in a one pot and single synthetic step in neutral and simple reaction conditions. All reactions were conducted in CH2Cl2 as solvent at room temperature without using any catalyst, and the stable products were obtained in high yields. The structures of all products were proved by 1H, 13C and 31P NMR and IR spectral and elemental analysis data.

Theoretical, Kinetic and Mechanistic Studies of the Reaction between Dialkyl Acetylenedicarboxylates, Triphenylphosphine and Pyrrole in Organic Solvents

The kinetics of the reaction between triphenylphosphine, dialkyl acetylenedicarboxylates and pyrrole in dry organic solvents at different temperatures have been studied spectrophotometrically. The observed overall second rate constant ( k2)for reaction decreases with decreasing solvent dielectric constant and media temperature; k2 follows the Arrhenius equation, and the overall reaction is first order in both the dialkyl acetylenedicarboxylate and triphenylphosphine concentrations. The proposed mechanism has been evaluated, and the activation parameters Δ G≠, Δ S≠ and Δ H≠ for the first, rate-determining step, as an elementary reaction have been determined on the basis of Eyring equation. In addition, the Z- and E-isomers have been optimized at HF and B3LYP levels with the 6-311++G** basis set; the more stable is the E-isomer, in agreement with experimental data. Furthermore, to better understand the intramolecular interactions, atoms in molecules (AIM) calculations and natural population analysis (NPA) methods have been carried out. The 1H, 13C, and 31P NMR data of these ylides are consistent with results obtained from theoretical calculations.

A joint experimental and theoretical investigation of kinetics and mechanistic study in a synthesis reaction between triphenylphosphine and dialkyl acetylenedicarboxylates in the presence of benzhydrazide

Stable crystalline phosphorus ylides were obtained in excellent yields from the 1:1:1 addition reaction between triphenylphosphine (TPP) and dialkyl acetylenedicarboxylates, in the presence of NH-acids, such as benzhydrazide. To determine the kinetic parameters of the reactions, they were monitored by UV spectrophotometery. The second order fits were automatically drawn and the values of the second order rate constant (k(2)) were calculated using standard equations within the program. At the temperature range studied the dependence of the second order rate constant (Ln k(2)) on reciprocal temperature was compatible with Arrhenius equation. This provided the relevant plots to calculate the activation energy of all reactions. Furthermore, useful information were obtained from studies of the effect of solvent, structure of reactants (different alkyl groups within the dialkyl acetylenedicarboxylates) and also concentration of reactants on the rate of reactions. On the basis of experimental data the proposed mechanism was confirmed according to the obtained results and a steady state approximation and the first step (k(2)) and third (k(3)) steps of the reactions were recognized as the rate determining steps, respectively. In addition, three speculative proposed mechanisms were theoretically investigated using quantum mechanical calculation. The results, arising from the second and third speculative mechanisms, were far from the experimental data. Nevertheless, there was a good agreement between the theoretical kinetic data, emerge from the first speculative mechanism, and experimental kinetic data of proposed mechanism.

1H Nmr Technique for Kinetic Investigation of Equilibrium between the Z- and E-Isomers in a Stable Phosphorus Ylide Involving a 2-Indolinone

For the first time, a kinetic investigation of the interchange process in the equilibrium between the Z- and E-isomers of a stable phosphorus ylide involving a 2-indolinone has been undertaken by the 1H NMR technique. Activation parameters such as k-1, k1, ktotal, Ea1, Ea-1, Eatotal, Δ S≠, Δ H≠ and Δ G≠ along with thermodynamic parameters such as Ke, Δ H°, Δ G° and Δ S° were obtained from experimental data for the forward and reverse reactions.

Three-Component and One-Pot Reaction between Aromatic Oximes and Dialkyl Acetylenedicarboxylates in the presence of Trimethyl Phosphite

A three-component reaction between trimethyl phosphite, dialkyl acetylene dicarboxylates and aromatic oximes is described as a simple and efficient route for the synthesis of dialkyl 2-(arylbenzylidene aminooxy)-3-(dimethoxy-phosphoryl) succinates in high yields.

Dynamic 1H NMR study around the carbon-carbon single bond and partial carbon-carbon double bond in the two particular phosphorus ylides and in an enaminoester

Herein, a series of separate dynamic (1)H NMR effects are reported at different temperatures within a particular enaminoester involving a phenanthridine. These effects are attributed to restricted rotation around the two single bonds such as carbon-carbon (H(a)-C-<arrow curve left)>C-H(b)) and nitrogen-carbon (NC<arrow curve left)>COOCH(3)). Activation energies (E(a)) for these interconversion processes in their rotational isomers are equal to 20 and 20 ± 1 kJ mol(-1), respectively. In addition, three dynamic (1)H NMR effects are investigated at different temperatures for a particular phosphorus ylide involving a 2-indolinone around the carbon-carbon single bond (H-C-<arrow curve left)>C-PPh(3)) within the two Z- and E-rotational isomers and partial carbon-carbon double bond (OCH(3)-C=<arrow curve right)>C-PPh(3)). Activation energies (E(a)) for these interconversion processes in rotational isomers are equal to 53, 63 and 73 ± 1 kJ mol(-1) , respectively. This behavior was also observed for other phosphorus ylide containing 2-mercaptobenzoxazole around the carbon-carbon single bond and partial carbon-carbon double bond with their relevant activation energies containing 13, 10 and 75 ± 1 kJ mol(-1), respectively.