59483-84-0Relevant articles and documents
Photo-on-Demand Base-Catalyzed Phosgenation Reactions with Chloroform: Synthesis of Arylcarbonate and Halocarbonate Esters
Dai, Namin,Eda, Kazuo,Harada, Hidefumi,Hashimoto, Yuka,Hosokawa, Sasuga,Kakiuchi, Toshifumi,Liang, Fengying,Okazoe, Takashi,Suzuki, Yuto,Tana, Gegen,Tsuda, Akihiko
, p. 9811 - 9819 (2021/07/20)
Carbonate esters are utilized as solvents and reagents for C1 building blocks in organic synthesis. This study reports a novel photo-on-demand in situ synthesis of carbonate esters with CHCl3 solutions containing a mixture of an aromatic or haloalkyl alcohol having relatively high acidity, and an organic base. We found that the acid-base interaction of the alcohol and base in the CHCl3 solution plays a key role in enabling the photochemical reaction. This reaction allows practical syntheses of diphenyl carbonate derivatives, haloalkyl carbonates, and polycarbonates, which are important chemicals and materials in industry.
Kinetic study of the phenolysis of bis(4-nitrophenyl) carbonate, bis(4-nitrophenyl) thionocarbonate, and methyl 4-nitrophenyl thionocarbonate
Castro,Angel,Arellano,Santos
, p. 6571 - 6575 (2007/10/03)
The reactions of a homogeneous series of phenols with bis(4-nitrophenyl) carbonate (BNPC), bis-(4-nitrophenyl) thionocarbonate (BNPTOC), and methyl 4-nitrophenyl thionocarbonate (MNPTOC) are subjected to a kinetic investigation in water, at 25.0 °C and ionic strength of 0.2 M (KCl). Under excess of phenol over the substrate, all the reactions obey pseudo-first-order kinetics and are first order in phenoxide anion. The reactions of BNPC show a linear Broensted-type plot with slope β=0.66, consistent with a concerted mechanism (one step). In contrast, those of BNPTOC and MNPTOC show biphasic Broensted-type plots with slopes β=0.30 and 0.44, respectively, at high pKa, and β=1.25 and 1.60, respectively, at low pKa, consistent with stepwise mechanisms. For the reactions of both thionocarbonates, the pKa value at the center of the BrSnsted plot (pKa0) is 7.1, which corresponds to the pKa of 4-nitrophenol. This confirms that the phenolyses of the thionocarbonates are stepwise processes, with the formation of an anionic tetrahedral intermediate. By the comparison of the kinetics and mechanisms of the title reactions with similar reactions, the following conclusions can be drawn: (i) Substitution of S- by O- in an anionic tetrahedral intermediate (T-) destabilizes it. (ii) The change of MeO by 4-nitrophenoxy in T- results in an increase of both the rate constant and equilibrium constant, for the formation ofT-, and also in an enlargement of the rate coefficient for the expulsion of 4-nitrophenoxide from T-. (iii) Substitution of an amino group in a tetrahedral intermediate by ArO destabilizes it. (iv) Secondary alicyclic amines and other amines show greater reactivity toward MNPTOC than isobasic phenoxide anions.
REACTIONS OF PENTAFLUOROPHENOL AND POLYFLUORINATED ALCOHOLS WITH CARBON TETRACHLORIDE IN THE PRESENCE OF ALUMINUM CHLORIDE
Petrova, T. D.,Ryabichev, A. G.,Savchenko, T. I.,Kolesnikova I. V.,Platonov, V. E.
, p. 1362 - 1366 (2007/10/02)
The reaction of pentafluorophenol, 2,2,3,3-tetrafluoropropyl alcohol, and 2,2,3,3,4,4,5,5-octafluoropentyl alcohol with carbon tetrachloride in the presence of aluminum chloride were investigated.The main products from the reaction of pentafluorophenol with these reagents are pentafluorophenoxytrichloromethane, di(pentafluorophenol) carbonate, and tri(pentafluorophenoxy)chloromethane.The ratios of the products depend on the reaction conditions.The use of a large excess of carbon tetrachloride leads to the preferential formation of pentafluorophenoxytrichloromethane.The addition of water promotes the formation di(pentafluorophenyl) carbonate.When heated with carbon tetrachloride and aluminum chloride and subsequently treated with water, 2,2,3,3-tetrafluoropropyl and 2,2,3,3,4,4,5,5-octafluoropentyl alcohols are converted into di(2,2,3,3-tetrafluoropropyl) carbonate and di(2,2,3,3,4,4,5,5-octafluoropentyl) carbonate respectively.
