17714-77-1Relevant articles and documents
EASY PREPARATION OF TRIPHENYLMETHYL CARBOXYLATES.
Hashimoto,Hayashi,Noyori
, p. 1431 - 1432 (1984)
A new method for triphenylmethylation of carboxylic acids and phenol is disclosed.
Zinc chloride homogeneous catalysis in the tritylation of hydroxyl- and amide-bearing molecules
Maltese, Maurizio,Vergari, Maria Cecilia,Donzello, Maria Pia
supporting information; experimental part, p. 483 - 487 (2011/03/18)
A tritylation protocol based on the transfer of the triphenylmethylcarbenium ion from trityl acetate to substrates having hydroxyls, in the presence of catalytic amounts of ZnCl2, is described. The advantages of this method are broad scope, mild conditions, and easy handling. The comparison with the procedure based on the use of equimolar mixture of TrCl and ZnCl2 in the presence of TEA shows that comparable results are obtained. However, only this method allows reactions of secondary or benzylic alcohols such as oxidation or formation of symmetric ethers to be suppressed. Both procedures are successfully extended to simple and substituted amides. Irrespective of its low solubility in acetonitrile, even asparagine can be directly tritylated on its amide group.
Nucleophilic acyl substitutions of anhydrides with protic nucleophiles catalyzed by amphoteric, oxomolybdenum species
Chen, Chien-Tien,Kuo, Jen-Huang,Pawar, Vijay D.,Munot, Yogesh S.,Weng, Shieu-Shien,Ku, Cheng-Hsiu,Liu, Cheng-Yuan
, p. 1188 - 1197 (2007/10/03)
(Chemical Equation Presented) Among six different group VIb oxometallic species examined, dioxomolybdenum dichloride and oxomolybdenum tetrachloride were the most efficient catalysts to facilitate nucleophilic acyl substitution (NAS) of anhydrides with a myriad array of alcohols, amines, and thiols in high yields and high chemoselectivity. In contrast to the well-recognized redox chemical behaviors associated with oxomolybdenum(VI) species, the catalytic NAS was unprecedented and tolerates virtually all kinds of functional groups. By using benzoic anhydride as a mediator for in situ generation of an incipient mixed anhydride-MoO2Cl2 adduct with a given functional alkanoic acid, one can achieve oleate, dipeptide, diphenylmethyl, N-Fmoc-α-amino, pyruvic, and tert-butylthio ester, N-tert-butylamide, and trityl methacrylate syntheses with appropriate protic nucleophiles. The amphoteric character of the Mo=O unit in oxomolybdenum chlorides was found to be responsible for the catalytic NAS profile as supported by a control NAS reaction of using an authentic adduct-MoOCl2(O2-CBu t)2 between pivalic anhydride and MoO2Cl 2 as the catalyst.
One-Pot Preparation of Tertiary Alkyl Carboxylates and Sulfonates from Ketones
Kuo, Mann-Yan,Liu, Kwang-Ting
, p. 2927 - 2929 (2007/10/02)
-