1149755-75-8Relevant academic research and scientific papers
A facile direct anti-selective catalytic asymmetric Mannich reaction of aldehydes with preformed N-Boc and N-Cbz imines
Chuan, Yong-Ming,Chen, Gui-Hua,Gao, Jiu-Zhi,Zhang, Hui,Peng, Yun-Gui
supporting information; experimental part, p. 3260 - 3262 (2011/04/27)
Anti-selective Mannich reactions of N-Boc and N-Cbz protected imines with unmodified aldehydes proceeded smoothly under the catalysis of a secondary amine-thiourea catalyst, which led to high yields (70%-95%) and excellent enantioselectivity (up to 964 dr
A designer axially chiral amino sulfonamide as an efficient organocatalyst for direct asymmetric mannich reactions of N-boc-protected imines
Kano, Taichi,Yamaguchi, Yukako,Maruoka, Keiji
supporting information; experimental part, p. 1838 - 1840 (2009/08/14)
The moderate nucleophilicity of the axially chiral amino sulfonamide (S)-1 suppresses the problematic side reactions, including aldol reactions, in the asymmetric Mannich reaction of N-Boc-protected imines with aldehydes. The corresponding adducts are obtained in good yield and excellent stereoselectivity (see scheme; Boc=tert-butoxycarbonyl, Tf=trifluoromethanesulfonyl).
A designer axially chiral amino sulfonamide as an efficient organocatalyst for direct asymmetric anti/-selective mannich reactions and syw-selective cross-aldol reactions
Kano, Taichi,Yamaguchi, Yukako,Maruoka, Keiji
supporting information; experimental part, p. 6678 - 6687 (2010/02/28)
A direct asymmetric Mannich reaction using a novel axially chiral amino sulfonamide (S)-3 that is highly anti- and enantioselective has been developed. For instance, in the presence of a catalytic amount of (S)-3, the reactions between aldehydes and a-imino esters proceeded smoothly to give anti Mannich products with a significantly higher antilsyn ratio and enantioselectivity than previously possible. By utilizing N-Boc-protected aro-matic imines instead of a-imino esters, the synthetically useful Boc protecting group and various aromatic or heteroaromatic substituents were installed into the anti Mannich products and consequently the substrate scope of the anri'-selective Mannich reaction and the synthetic utility of the anti Mannich products have been expanded. The axially chiral amino sulfonamide (S)-3 has also been successfully applied to asymmetric direct cross-aldol reaction between two different aldehydes. The catalyst (S)-3 has the advantage of giving mainly syn products, whereas proline shows the opposite anti selectivity.
