1233718-39-2Relevant academic research and scientific papers
A 4-hydroxypyrrolidine-catalyzed mannich reaction of aldehydes: Control of anti-selectivity by hydrogen bonding assisted by bronsted acids
Gomez-Bengoa, Enrique,Maestro, Miguel,Mielgo, Antonia,Otazo, Itziar,Palomo, Claudio,Velilla, Irene
, p. 5333 - 5342 (2010)
An anti-selective Mannich reaction of aldehydes with N-sulfonyl imines has been developed by using a 4-hydroxypyrrolidine in combination with an external Bronsted acid. The catalyst design is based on three elements: the ct-substituent of the pyrrolidine, the 4-hydroxy group, and the Bronsted acid, the combination of which is essential for high chemical and stereochemical efficiency. The reaction works with aromatic aldehydederived imines, which have rarely been employed in previously reported enamine-based anti-Mannich reactions. Additionally, both N-tosyl and N-nosyl imines can be successfully used and the Mannich adducts can be easily reduced or oxidized, and after N-deprotection the corresponding ss-amino acids and ss-amino alcohols can be obtained with good yields. The results also show that this ternary catalytic system may be practical in other enamine-based reactions.
