41890-58-8Relevant academic research and scientific papers
Boc-protected amines via a mild and efficient one-pot curtius rearrangement
Lebel, Helene,Leogane, Olivier
, p. 4107 - 4110 (2005)
(Chemical Equation Presented) The reaction of a carboxylic acid with di-tert-butyl dicarbonate and sodium azide allowed the formation of an acyl azide intermediate, which undergoes a Curtius rearrangement in the presence of tetrabutylammonium bromide and zinc(II) triflate. The trapping of the isocyanate derivative in the reaction mixture led to the desired tert-butyl carbamate in high yields at low temperature. These reaction conditions are compatible with a variety of substrates, including malonate derivatives, which provide access to protected amino acids.
Convenient and Simple Esterification in Continuous-Flow Systems using g-DMAP
Okuno, Yoshinori,Isomura, Shigeki,Sugamata, Anna,Tamahori, Kaoru,Fukuhara, Ami,Kashiwagi, Miyu,Kitagawa, Yuuichi,Kasai, Emiri,Takeda, Kazuyoshi
, p. 3587 - 3589 (2015/11/17)
The utility and applicability of polyethylene-g-polyacrylic acid-immobilized dimethylaminopyridine (g-DMAP) as a catalyst in a continuous-flow system were investigated for decarboxylative esterification. High catalytic activity toward acylation was provided by g-DMAP containing a flexible grafted-polymer structure. During decarboxylation, carboxylic acids and alcohols were converted cleanly using di-tert-butyl dicarbonate (Boc2O) as a coupling reagent, which reduced by-products. In addition, the use of Boc2O resulted in the formation of tert-butyl esters. These esterifications dramatically reduced the reaction time under continuous-flow conditions, with a residence time of approximately 2 min. This highly efficient esterification procedure will provide more practical industrial applications.
Catalytic enantioselective construction of all-carbon quaternary stereocenters: Synthetic and mechanistic studies of the C-acylation of silyl ketene acetals
Mermerian, Ara H.,Fu, Gregory C.
, p. 5604 - 5607 (2007/10/03)
With the aid of an appropriate chiral catalyst, acyclic silyl ketene acetals react with anhydrides to furnish 1,3-dicarbonyl compounds that bear all-carbon quaternary stereocenters in good ee and yield. Mechanistic studies provide strong support for a catalytic cycle that involves activation of both the electrophile (anhydride → acylpyridinium) and the nucleophile (silyl ketene acetal → enolate).
Catalytic enantioselective synthesis of quaternary stereocenters via intermolecular C-acylation of silyl ketene acetals: Dual activation of the electrophile and the nucleophile
Mermerian, Ara H.,Fu, Gregory C.
, p. 4050 - 4051 (2007/10/03)
A nucleophile-catalyzed asymmetric intermolecular C-acylation of silyl ketene acetals by anhydrides has been developed, furnishing quaternary stereocenters with high enantioselectivity. Mechanistic studies support the hypothesis that the reaction involves activation both of the silyl ketene acetal (generation of an enolate) and of the anhydride (formation of an acylpyridinium ion). Copyright
An Improved and Convenient Synthesis of Esters Using 1,1'-Carbonyldiimidazole and a Reactive Halide
Kamijo, Tetsuhide,Harada, Hiromu,Iizuka, Kinji
, p. 5044 - 5047 (2007/10/02)
The esterification of carboxylic acid proceeded easily in a one-pot reaction with 1,1'-carbonyldiimidazole in the presence of a reactive halide under neutral reaction conditions in high yields. Keywords - esterification: 1,1'-carbonyldiimidazole; formylation; tert-butyl ester; imidazolium salt; one-pot reaction
