38513-65-4Relevant academic research and scientific papers
The Photochemistry of Methoxy-Substituted Benzyl Acetates and Benzyl Pivalates: Homolytic vs Heterolytic Cleavage
Pincock, J. A.,Wedge, P. J.
, p. 5587 - 5595 (1994)
The multiple methoxy-substituted benzyl acetates (3g-i) and benzyl pivalates (4g-i) have been photolyzed in methanol solution.The products of these reactions are derived from two critical intermediates; the benzyl radical/acyloxy radical pair and the benzyl cation/carboxylate anion pair.As predicted by the meta effect, the yield of ion-derived product, the methyl ether in this case, was enhanced by the presence of the m-methoxy groups.The yield of ether, for the acetate esters, varied from 2percent for the 4-methoxy-substituted ester to 66percent for the 3,4,5-trimethoxy-substituted ester.In contrast, the yield of ether, for the pivalate esters, varied from 1percent for the 4-methoxy-substituted ester to 20percent for the 3,4,5-trimethoxy-substituted one.The meta effect does not explain these differences; electron transfer converting the radical pair to the ion pair is still an important pathway in the mechanism for ion formation.A quantitative analysis of the yield of the ethers was done in order to obtain the electron-transfer rate constants.This analysis revealed that the yield of the ethers was higher than expected based on previous results for other substituted benzyl acetates.A possible explanation for this discrepancy is that internal return of the radical pair to starting material for the acetate esters is more efficient than for the pivalate esters.Also, the esters 3k and 3l, were prepared to study the effect of electron-withdrawing groups in the meta position.For these esters, the benzylic cleavage reactions were inefficient and an isomerization reaction, the benzvalene rearrangement, was competitive.
Selective acetylation of primary alcohols by ethyl acetate
Singha, Raju,Ray, Jayanta K.
, p. 5395 - 5398 (2016/11/11)
A KOtBu and ethyl acetate mediated efficient methodology has been developed for the acetylation of primary and secondary alcohols where ethyl acetate is the source of acetyl group. The reaction is fast, mild, efficient, and highly selective towards the primary alcohols.
A novel silver nanoparticle embedded mesoporous polyaniline (mPANI/Ag) nanocomposite as a recyclable catalyst in the acylation of amines and alcohols under solvent free conditions
Mandi, Usha,Roy, Anupam Singha,Banerjee, Biplab,Islam, Sk. Manirul
, p. 42670 - 42681 (2015/02/19)
A mesoporous polyaniline/silver (mPANI/Ag) nanocomposite has been prepared using mesoporous organic polymer polyaniline with silver nitrate via radical polymerization of aniline monomer in the presence of hydrochloric acid. The mPANI/Ag nanocomposite has been characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), energy-dispersive X-ray spectra (EDX), Fourier transform infrared spectroscopy (FT-IR), and ultraviolet-visible absorption spectra (UV-vis). The XRD patterns indicated that the crystalline phase of Ag is cubic. TEM images show that the Ag nanoparticles are well dispersed in the mesoporous polyaniline matrix. The mPANI/Ag acts as an efficient heterogeneous nanocatalyst in the acylation of substituted amines and alcohols using acetic acid. The catalyst is air-stable, inexpensive, easy to prepare and can be reused several times without a significant decrease in activity and selectivity. This journal is
Ruthenium(III) chloride catalyzed acylation of alcohols, phenols, thiols, and amines
Kanta De, Surya
, p. 2919 - 2922 (2007/10/03)
Ruthenium(III) chloride catalyzes the acylation of a variety of phenols, alcohols, thiols, and amines under mild conditions. Some of the major advantages of this method are high yields, short reaction times, ease of operation, and compatibility with other protecting groups.
Rapid and efficient acetylation of alcohols and phenols with acetic anhydride using tin(IV) porphyrin as catalyst
Tangestaninejad, Shahram,Habibi, Mohammad Hossein,Mirkhani, Valiollah,Moghadam, Majid
, p. 1337 - 1343 (2007/10/03)
The efficient and rapid esterification of alcohols and phenols in acetic anhydride was achieved by tin(IV) tetraphenylporphyrin perchlorate [SnIV (tpp) (ClO4)2] as catalyst in high yields. SnIV (tpp) (ClO4)2 showed highly catalytic activity on the acetylation reaction.
1,3-Dimethoxy-5-methylene-1,3-cyclohexadiene Compounds with Leaving Groups at C6: Generation, Solvolytic Reactivity, and Their Importance in the Photochemistry of 3,5-Dimethoxybenzyl Derivatives
DeCosta,Howell,Pincock,Pincock,Rifai
, p. 4698 - 4705 (2007/10/03)
The photochemistry of 3,5-dimethoxybenzyl compounds with the leaving groups acetate (1a), chloride (1b), bromide (1c), iodide (1d), diethyl phosphate (1e), and trimethylamine (1f), as the chloride, was examined by both product studies and flash photolysis. The isomeric triene, 5-methylene-1,3-cyclohexadiene derivative was observed for the acetate (2a), diethyl phosphate (2e) and trimethylammonium chloride (2f). The solvolysis of these derivatives, 2, was examined in alcohol solvents and the rate correlation with YOTS values gave m = 0.47 (2a) and 0.63 (2e), suggesting SN1 reactivity but with an early transition state. Quantum yields for formation of 2a and 2e indicated that these trienes play only a minor role (～16%) in the overall photochemistry of the corresponding arylmethyl substrates.
An Efficient Synthesis of Dimethoxy Phthalides
Paradkar, Madhusudan V.,Kulkarni, Sanjeev A.,Joseph, Augustine R.,Ranade, Anup A.
, p. 944 - 956 (2007/10/03)
This communication describes a convenient route for the synthesis of naturally occurring dimethoxy phthalides.
A facile one-step conversion of aromatic aldehydes to acetates
Baruah
, p. 60 - 61 (2007/10/03)
Aromatic aldehydes are efficiently converted to the corresponding benzyl acetates with acetic anhydride and zinc in the presence of acidic aluminium oxide in dichloromethane at room temperature.
Taxane synthesis through intramolecular pinacol coupling at C-1-C-2. Construction and oxidative transformations of a C-aromatic taxane diene
Swindell, Charles S.,Chander, Madhavi C.,Heerding, Julia M.,Klimko, Peter G.,Rahman, Leera T.,Roman, J. Venkat,Venkataraman, Hemalatha
, p. 1101 - 1108 (2007/10/03)
A ten-linear-step construction of C-aromatic taxane diene 14 from ethylisopropyl ketone, acryloyl chloride, and commercially available 8 is reported. This sequence concludes with an intramolecular pinacol coupling carried out on 13. 14 is oxidized by m-ch
An AC → ABC approach to taxol involving B-ring closure at C-1-C-2
Swindell,Chander,Heerding,Klimko,Rahman,Venkat Raman,Venkataraman
, p. 7005 - 7008 (2007/10/02)
The treatment of keto aldehyde 13 with low-valent Ti results in a stereoselective intramolecular pinacol coupling that produces taxane synthesis intermediate 14.
