18133-58-9Relevant academic research and scientific papers
CuCl/bpy-promoted unusual Z-stereoselective synthesis of trichloroacetic acid phenyl ester for Hirshfeld surface analysis and DFT study
Tittal, Ram Kumar,Ram, Ram Nath,Nirwan, Ayushi,Ghule, Vikas D.,Kumar, Satish
, p. 300 - 309 (2019/03/12)
A trichloromethyl ester devoid of suitably substituted C[dbnd]C bond, any leaving group or a H-atom at the β-position to the radical, which are otherwise known for ATRA/ATRC, 1,2-rearrangement/fragmentation or simple 1,2-H shift respectively, in a reaction of trichloro-acetic acid phenyl ester with 2 mol equiv CuCl/bpy in reflux DCE or benzene under inert N2 condition resulted to stereoselective synthesis of Z-2,3-dichloro-but-2-enedioic acid diphenyl ester and/or formation of reductive de-chlorination side product. The Z-stereochemistry of the product was confirmed by X-ray diffraction spectroscopy of Z-2,3-dichloro-but-2-enedioic acid dinaphthalen-1-yl ester which crystalizes in monoclinic system of P21/c symmetry elements. Hirshfeld surface analysis of experimentally established structure of Z-2,3-dichloro-but-2-enedioic acid diphenyl ester unrevealed the intermolecular interactions showing both H-bonding and short contacts. The stereochemistry was also interpreted computationally using Density Functional Theory at B3LYP/6-311G(d,p) level of theory. The calculated energies, energy gap and balance between the electrostatic potential on the molecular surface were computed which revealed unusual formation of less stable Z-isomer.
Correlation analysis of carbonyl carbon 13C NMR chemical shifts, IR absorption frequencies and rate coefficients of nucleophilic acyl substitutions. A novel explanation for the substituent dependence of reactivity
Neuvonen, Helmi,Neuvonen, Kari
, p. 1497 - 1502 (2007/10/03)
Rate coefficients of nucleophilic acyl substitutions, carboxylate carbon 13C NMR chemical shift values and v(C=O) frequencies of several series of aryl and acyl substituted aryl acetates or alkyl benzoates have been investigated. An increasing electron-withdrawal by the acyl or aryl substituents results in higher reaction rates, upfield 13C NMR chemical shifts and higher frequencies of the C=O stretching. Good correlations are observed for the log k versus δC(C=O) plots. The increase of the reaction rate with increased electron density at the C=O carbon (as proved by 13C NMR shifts) contradicts the previous concept of increased electrophilicity of the carbonyl carbon by electron-withdrawing substituents. The rate increase is now attributed to the decrease of the ester ground state resonance stabilization caused by electron-withdrawing substituents. The use of log k versus δc(C=O) correlations is presented as a practical method to evaluate rate coefficients especially for compounds for which Hammett type correlations cannot be used.
Selectivity of the Aromatic Plumbylation Reaction
Stock, Leon M.,Wright, Terry L.
, p. 4645 - 4648 (2007/10/02)
The plumbylation of toluene in dichloroacetic acid yields initially 5.4percent 2-, 1.8percent 3-, and 92.7percent 4-methylphenyllead(IV) dichloroacetates.The toluene to benzene rate ratio under these conditions is 59.9.The partial rate factors are oMef = 9.64, mMef = 3.21, pMef = 331.The plumbylation of toluene in trifluoroacetic acid yields aryl trifluoroacetates and biaryls.Analysis of these products suggest that the plumbylation reaction yields 17.9percent 2-, 3.2percent 3-, and 78.9percent 4-methylphenyllead (IV) trifluoroacetates in the initial step of the reaction.The toluene to benzene rate ratio is 114 under these conditions.The partial rate factors are oMef = 61.2, mMef = 10.8, and pMef = 540.These observations suggest that the plumbylation reaction is a typical electrophilic substitution and that the reaction is significantly more selective than thallation or mercuration.
