132836-68-1Relevant academic research and scientific papers
Substrate Acidities and Conversion Times for Reactions of Amides With Di-tert-butyl Dicarbonate
Hansen, Marvin M.,Harkness, Allen R.,Coffey, D. Scott,Bordwell, Frederick G.,Zhao, Yongyu
, p. 8949 - 8952 (1995)
The conversion time for 4-dimethylaminopyridine catalyzed reaction of amides with tert-butyl dicarbonate varies dramatically with substrate acidity.The pKa's in DMSO of some amides are determined to support correlation of reactivity with substr
Electrogenerated Superoxide-Activated Carbon Dioxide. A New Mild and Safe Approach to Organic Carbamates
Casadei, Maria Antonietta,Moracci, Franco Micheletti,Zappia, Giovanni,Inesi, Achille,Rossi, Leucio
, p. 6754 - 6759 (2007/10/03)
The electrochemical reduction of O2 (E = -1.0 V vs SCE) in dipolar aprotic solvents in the presence of CO2 gave a carboxylating reagent (O2·-/CO2) able to convert amines and different types of their derivatives into carbamates. Primary and secondary aliphatic and aromatic amines were converted into the corresponding ethyl carbamates by the addition of EtI to the carbamate anions generated in the first step of the reactions. The yields were dependent on the nucleophilicity of the nitrogen atom ω-Bromoethyl- and propylamine gave 2-oxazolidinone and tetrahydro-l,3-oxazm-2-one in moderate yields. N-Acyl or N-(alkoxycarbonyl)alkylamines bearing a leaving group at the β position of the alkyl substituent were converted into 3-substituted-2-oxazolidinones in high yields. By using chiral substrates, enantiopure 3-alkoxycarbonyl(or acyl)-4-substituted oxazolidin-2-ones (70-85% isolated yields) were obtained. This represents a new mild and safe route to these important auxiliaries for asymmetric synthesis. Some limitations of the process are also evidenced and accounted for.
Simple and efficient N-acylation reactions of chiral oxazolidinone auxiliaries
Ager, David J.,Allen, David R.,Schaad, David R.
, p. 1283 - 1285 (2007/10/03)
A simplified procedure for the N-acylation of oxazolidin-2-one chiral auxiliaries has been developed. The acylations occur at room temperature in the presence of triethylamine and catalytic quantities of 4-(N,N-dimethylamino)pyridine, thereby eliminating the necessity for a strong base such as butyllithium. Acylations with both symmetrical and mixed anhydrides, as well as acid chlorides, occur with a wide variety of oxazolidinone auxiliaries.
