Recent Developments and Perspectives in the Asymmetric Mannich Reaction

Abstract

The asymmetricM annichr eactioni savery important method for CÀCb ond formation,a nd it is the classical method for the preparation of b-amino ketones and aldehydes. The resulting b-amino carbonyl compounds are widely found in nature, which attests to the importance of this reaction. This Focus Review providesa no verview of asymmetricM annich reactions, the various catalysts that have been used, and its applications,f or papers published since 2013. Scheme1.The Mannich reaction.Scheme2.The mechanism of the Mannich reaction;reproduced with permissionfrom Ref.[1]. andhi University. His research interests are in the areaso fo rganic synthesis, medicinal chemistry,a nd catalysis, in particularr uthenium-, iron-, zinc-, and copper-catalyzedr eactions. His h-index is 24.

Recent Progress in the Asymmetric Syntheses of α‐Heterofunctionalized (Masked) α‐ and β‐Amino Acid Derivatives

“…In contrast to the rarely investigated above mentioned α‐amination of β‐AA precursors, the asymmetric construction of the α,β‐diamino acid skeleton via Mannich type reactions has been explored in much detail. Given the variety of different catalysis protocols to achieve asymmetric Mannich type reactions, [ 69 ] this methodology is without doubt one of the most versatile strategies to access the α,β‐diamino acid scaffold from simple starting materials. [ 7,70–85 ]…”

Mannich-Type Reaction of Aldimines with 2-Silyloxydienes Catalyzed by Ammonium Chloride

“…The solvent was removed at reduced pressure to give the product 4o as a white solid (0.21g, 65%). International Journal of Organic Chemistry Data for 4o; 1…”

“…Mannich-type reactions are widely recognized as a powerful method for constructing a variety of b-aminoketones [1]- [6]. However, Mannich-type reaction of imines with 2-silyloxydienes, which provides easy access to β-aminoketones having a terminal olefin, is still challenging because [4 + 2] type cycloadducts [7]- [15] or mixtures of Mannich-type products and cycloadducts [16] [17] [18] are obtained in most cases, as shown in Figure 1.…”

“…The crude product was purified by flash column chromatography (ethyl acetate: n-hexane = 1:6) to afford 3.Data for 3a; colorless oil, 0.34 g, 95% 1. H NMR (CDCl 3 , 500 MHz) δ 3.17 (dd, 1H, J = 15.4 Hz, 5.7 Hz), 3.23 (dd, 1H, J = 15.4 Hz, 7.5 Hz), 3.85 (s, 3H), 4.97 Hz, 5.7 Hz), 3.20 (dd, 1H, J = 15.5 Hz, 6.9 Hz), 3.74 (s, 3H), 3.83 (s, 3H), 4.91 (dd, 1H, J = 6.3 Hz, 6.3 Hz), 6.46 (d, 1H, J = 1.7 Hz), 6.61 -6.63 (m, 4H), 6.81 -6.85 (m, 2H), 7.25 -7.37 (m, 5H), 7.42 -7.47 (m, 3H); HRMS (EI) m/z [M] + calcd.…”

Synthesis and Applications of Polymer Chelating Resins Containing Schiff Base

“…Among the different kinds of organic materials, Schiff base or azomethine is a compound containing functional group. Depending on the groups attached to HC=N of Schiff base, these materials are also well-known as (a) imines [1,2]; (b) diimines when derived from amines and (c) ketamine's when derived from ketones [3]. Schiff-bases have large applications in different fields and have got the wide attention to several researchers, scientists and technologists [4].…”