21731-17-9Relevant articles and documents
A mechanistic study of the ammonolysis of alkyl acetoacetates in water. Formation of 1,5-dimethyl-2,6,9-triaza-bicyclo[3.3.1]nonane-3,7-dione as the main product
Paredes, Rodrigo,Abonia, Rodrigo,Cadavid, John,Moreno-Fuquen, Rodolfo,Jaramillo, Alonso,Hormaza, Angelina,Ramirez, Alfonso,Kennedy, Allan
, p. 55 - 60 (2002)
Ammonolysis of alkyl acetoacetates with 15% NH3 in water at room temperature initially lead to formation of alkyl β-aminocrotonates which slowly converted into 1,5-dimethyl-2,6,9-triaza-bicyclo[3.3.1]nonane-3,7-dione as the main product.
Practical, catalytic enantioselective hydrogenation to synthesize N -unprotected β-amino esters
Matsumura, Kazuhiko,Zhang, Xiaoyong,Hori, Kiyoto,Murayama, Toshiyuki,Ohmiya, Tadamasa,Shimizu, Hideo,Saito, Takao,Sayo, Noboru
experimental part, p. 1130 - 1137 (2012/01/03)
Practical and simple catalytic enantioselective hydrogenation reactions to synthesize N-unprotected β-amino esters have been developed: (1) asymmetric hydrogenation of N-unprotected β-enamine ester and (2) asymmetric direct reductive amination of β-keto esters using ammonium salts. A Ru-DM-SEGPHOS complex was used as the catalyst in both cases and gave high enantioselectivity, high reactivity, and wide substrate applicability. These protocols greatly reduced reaction time and waste compared to conventional synthetic routes. The direct reductive amination route was demonstrated on a >100 kg scale.
Detection and elimination of product inhibition from the asymmetric catalytic hydrogenation of enamines
Hansen, Karl B.,Rosner, Thorsten,Kubryk, Michele,Dormer, Peter G.,Armstrong III, Joseph D.
, p. 4935 - 4938 (2007/10/03)
(Chemical Equation Presented) The catalytic asymmetric hydrogenation of enamine amides and esters with catalyst Rh-1a, prepared from ferrocenyl based ligand 1a or 1b and [(COD)RhCl]2, has been shown through kinetic studies to suffer from product inhibition. Enamine ester substrates have also been shown to be incompatible with the amine products of the reaction in methanol. In situ protection of the amine products with di-tert-butyl dicarbonate eliminates functional group incompatibility of ester substrates and eliminates product inhibition in the reaction.