Study On The Catalytic Asymmetric Addition Of 2-methyl-1-butene-3-yne To Aldehydes

Addition of metallated terminal alkynes to carbonyls is considered as an effective route for the synthesis of chiral propargyl alcohols and has gained considerable significance in recent years.And Optically active propargyl alcohols are important and versatile building blocks for the synthesis of a wide range of pharmaceuticals and natural products.For the possible further transformations of functionalized group,the asymmetric addition of 2-methyl-1-butene-3-yne to aldehydes should have more potential applications than phenylacetylene for the synthesis of complex bioactive natural products.Herein we mainly discuss design and synthesis of some chiral ligands or catalysts and their application to the asymmetric addition of 2-Methyl-1-butene-3-yne to aldehydes.Double bond in the molecular of 2-methyl-1-butene-3-yne have many Variability. Addition of 2-methyl-1-butene-3-yne to carbonyls have big value.Also it is different with phenylacetylene,such as smaller and acidity,which result that its addition to carbonyls is different withPhenylacetylene to carbonyls.Sulfonamide ligand 6a and 6b was easily prepared in three simple steps and applied in the enantioselective addition of 2-methyl-1-butene-3-yne to aldehydes.The corresponding chiral tertiary propargylic alcohols were obtained with enantiomeric excesses of up to 86%,yield of 78%under very mild conditions.