605683-32-7Relevant articles and documents
One-pot organocatalytic direct asymmetric synthesis of γ-amino alcohol derivatives
Córdova, Armando
, p. 1651 - 1654 (2003)
This report describes the unprecedented use of unmodified aldehydes as donors in catalytic three component one-pot asymmetric Mannich reactions. The Mannich-type reactions were also readily performed for the first time with both in situ generated and pref
Dynamic kinetic resolution in the asymmetrie synthesis of β-amino acids by organocatalytic reduction of enamines with trichlorosilane
Malkov, Andrei V.,Stoncius, Sigitas,Vrankova, Kvetoslava,Arndt, Matthias,Kocovsky, Pavel
supporting information; experimental part, p. 8082 - 8085 (2009/09/29)
A new methodology based on the organocatalytic asymmetric hydrosilylation of enamines that allows a direct access to a range of β3 and β2.3-amino acid derivatives was presented. The results show a successful reduction of aromatic substrates, a sterically more hindered ortho-substituted derivatives, and the thiophenyl analogue exhibiting lower reactivity. Fast enamine-imine equilibration is crucial as imines are chiral but racemic, while α-alkyl β-amino acids can be accessed by the symmetrical Mannich reaction. The α-alkyl derivatives have relative and absolute configuration due to their reduction with LiAlH4 into a known amino alcohols. Predominant formation of the anti isomer in 3o is consistent with conformation of the imine intermediate in the catalytic reduction.
The direct, enantioselective, one-pot, three-component, cross-Mannich reaction of aldehydes: The reason for the higher reactivity of aldimine versus aldehyde in proline-mediated Mannich and aldol reactions
Hayashi, Yujiro,Urushima, Tatsuya,Shoji, Mitsuru,Uchimaru, Tadafumi,Shiina, Isamu
, p. 1595 - 1604 (2007/10/03)
In the proline-mediated Mannich and aldol reactions of propanal as a nucleophile, the aldimine prepared from benzaldehyde and p-anisidine is about 7 times more reactive than the corresponding aldehyde, benzaldehyde, as an electrophile. This higher reactivity of aldimine over aldehyde is attributed to the carboxylic acid of proline protonating the basic nitrogen atom of the aldimine more effectively than the oxygen atom of the aldehyde, an explanation which has been both experimentally and theoretically verified.
