The Asymmetric Autocatalysis Of Mannich Reaction

In the field of asymmetric organic catalysis, asymmetric autocatalysis is almost at thebeginning stage, in addition to Soai reaction reported by Professor Kenso Soai, the few otherantocatalytic reaction is found. Asymmetric autocatalysis attracts much attention becauseasymmetric organic chiral amplification is considered closely related to the origin of chiral.Finding chiral asymmetric autocatalytic reaction has become a hotspot of organic catalystsrecent years, but little success has been reported. In view of the importance of Mannichreaction in organic synthesis, the purpose of this project is to explore the asymmetriccatalyzed Mannich reactions.This experiments were conducted with hydroxy acetone, nitrobenzaldehyde, anisidine;hydroxy acetone, 4-Bromobenzaldehyde, anisidine; hydroxy acetone, benzaldehyde, anisidine;acetone, iso-valeraldehyde, p-anisidine three components of the catalytic asymmetricMannich reaction, and hydroxy acetone, 4-Bromobenzaldehyde, anisidine three componentswere tried in the cis-catalyst and trans-catalyst. Through many experiments, the influence ofthe amount of catalyst and acetic acid on the yield and ee value of catalytic reaction wascompared. Experiment was monitored by Thin Layer Chromatography, the structures of theproducts were identified by Nuclear Magnetic Resonance, the ee values of products weredeterminated by HPLC. Asymmetric autocatalytic chiral amplification substrates wereexpected to be found.Through 19 groups of the asymmetric autocatalytic tests, it was found that they all havethe effect of asymmetric antocatalysis. The two asymmetric Mannich reactions of threecomponents hydroxyacetone- nitrobenzaldehyde- anisidine, acetone- isoamylaldehyde-anisidine showed chiral amplification effect. The amount of catalyst affected thereaction yield less. In some reactions, the effect of the acetic acid to the yield and ee value ofthe reaction is obvious. The experiment proved that the asymmetric autocatalytic Mannichreaction is real possible, and amplification reactions were found.