Highly Efficient Synthesis Of?-Substituted Aliphatic Aldehydes And Its Asymmetric Cross-Aldol Reaction With Glyoxylate Catalyzed By New Organocatalysts

The asymmetric Aldol reaction is an important reaction in the formation of C-C bonds in organic chemistry.It is often used in the preparation of?-hydroxycarbonyl compounds.Asymmetric Aldol reactions are very popular and important research in organic chemistry.In previous research,most of catalysts are natural proline and other small molecular oganocatalysts.Ketones are most commonly used as the donor in asymmetric Aldol reactions,albeit aldehydes as the donors for the reaction have been rarely disclosed thus far.Two parts are included in this work.1.A series of?-substituted aliphatic aldehydes were efficiently and readily synthesized under mild conditions by using benzaldehydes and propionaldehyde as raw materials,and the yield reached 92%.The substituted groups'effect of benzaldehydes on the reaction yield was studied and the asymmetric cross-Aldol reaction catalyzed by the new organic catalyst was used to synthesize two contiguous stereocenters compounds containing a all carbon quaternary stereocenter substructure.2.Eight new organic catalysts were synthesized from inexpensive natural and unnatural?-amino acids.Their catalytic asymmetric cross-Aldol reaction between aldehydes was subsequently studied.The synthesis step of the catalyst was simple and achieved in high yields.The effect of additives and solvents on the Aldol reaction catalyzed by the catalyst C₁was investigated for the asymmetric Aldol reaction between two aldehydes.The asymmetric cross-Aldol reaction was then extended to synthesize D-furanone compound,providing potential utility of this work in the chiral drug synthesis.