<sup>19</sup>F Nuclear Magnetic Resonance Spectroscopy for the Quantitative Detection and Classification of Carbonyl Groups in Lignins
作者:Behzad C. Ahvazi、Claudia Crestini、Dimitris S. Argyropoulos
DOI:10.1021/jf980431p
日期:1999.1.1
carbonyl groups present in lignins were also investigated by trifluoromethylating them in the presence of catalytic amounts of tetramethylammonium fluoride (TMAF), followed by hydrolysis with TMAF in tetrahydrofuran. By using a variety of selective reactions, it became possible to assign a number of prominent (19)F NMR signals to a variety of carbonyl groups present in lignins. These studies demonstrated
Nucleophilic Trifluoromethylation of Carbonyl Compounds: Trifluoroacetaldehyde Hydrate as a Trifluoromethyl Source
作者:G. K. Surya Prakash、Zhe Zhang、Fang Wang、Socrates Munoz、George A. Olah
DOI:10.1021/jo400202w
日期:2013.4.5
feasible nucleophilic trifluoromethylating protocol has been developed using trifluoroacetaldehyde hydrate as an atom-economical trifluoromethyl source. The reaction was found to be applicable to the nucleophilic trifluoromethylation of a broad spectrum of carbonylcompounds with satisfactory yields in general. DFT calculations have been performed to provide mechanistic insight into the present and related
Quantitative trifluoromethylation of carbonyl-containing lignin model compounds
作者:B.C. Ahvazi、D.S. Argyropoulos
DOI:10.1016/0022-1139(96)03431-8
日期:1996.6
lignin model compounds was made possible by using Ruppert' s reagent in the presence of tetramethylammonium fluoride (TMAF), followed by hydrolysis with aqueous HF. These studies demonstrate that such a method can quantitatively convert carbonylgroups to the CF3-containing compounds, thus qualifying the procedure as a potential analytical tool for the determination of carbonylgroups in lignins.
Substituent Effects on the Solvolysis of 1,1-Diphenyl-2,2,2-trifluoroethyl Tosylates: Comparison between Symmetrically Disubstituted and Monosubstituted Systems
The solvolysis rates of 1-(substituted phenyl)-1-phenyl-2,2,2-trifluoroethyl and 1,1-bis(substituted phenyl)-2,2,2-trifluoroethyl tosylates or bromides were conductimetrically measured at 25.0 °C i...
Amidinate Salt of Hexafluoroacetone Hydrate for the Preparation of Fluorinated Compounds by the Release of Trifluoroacetate
作者:Mark V. Riofski、Allison D. Hart、David A. Colby
DOI:10.1021/ol303291x
日期:2013.1.4
A powerful, new reagent, an amidinate salt of hexafluoroacetone hydrate, is an air-stable salt that can be used for the preparation of fluorinated organic molecules. Nucleophilic trifluoromethylation reactions are demonstrated following the base-promoted release of trifluoroacetate. This reagent is soluble in many polar organic solvents and produces fluoroform, following the release of trifluoroacetate