23912-63-2Relevant academic research and scientific papers
Probing α-Amino Aldehydes as Weakly Acidic Pronucleophiles: Direct Access to Quaternary α-Amino Aldehydes by an Enantioselective Michael Addition Catalyzed by Br?nsted Bases
García-Urricelqui, Ane,de Cózar, Abel,Mielgo, Antonia,Palomo, Claudio
, p. 2483 - 2492 (2020/12/25)
The high tendency of α-amino aldehydes to undergo 1,2-additions and their relatively low stability under basic conditions have largely prevented their use as pronucleophiles in the realm of asymmetric catalysis, particularly for the production of quaternary α-amino aldehydes. Herein, it is demonstrated that the chemistry of α-amino aldehydes may be expanded beyond these limits by documenting the first direct α-alkylation of α-branched α-amino aldehydes with nitroolefins. The reaction produces densely functionalized products bearing up to two, quaternary and tertiary, vicinal stereocenters with high diastereo- and enantioselectivity. DFT modeling leads to the proposal that intramolecular hydrogen bonding between the NH group and the carbonyl oxygen atom in the starting α-amino aldehyde is key for reaction stereocontrol.
Stereoselective intramolecular cyclization of γ-allylbenzamide via π-allylpalladium complex catalyzed by Pd(0)
Pham, Van-Thoai,Joo, Jae-Eun,Lee, Kee-Young,Kim, Tai-Won,Mu, Yu,Ham, Won-Hun
experimental part, p. 2123 - 2131 (2010/04/26)
An efficient procedure for synthesizing oxazines was developed by the palladium(0)-catalyzed intramolecular cyclization of a benzamide through a π-allylpalladium (II) complex. Interestingly, the diastereoselectivity of oxazine ring formation was dominantly controlled by the bulkiness of various protecting groups on the secondary alcohols.
