New Hybrid-type Squaramide-Fused Amino Alcohol Organocatalystfor Enantioselective Domino Michael Addition/Cyclization Reactionof Oxoindolines with Cyclic 1,3-Diketones

摘要

The new hybrid-type squaramide-fused aminoalcohol containing both a Br?nsted basic site and hydrogenbonding sites in the molecule showed a high catalytic activityas an organocatalyst in the enantioselective domino Michaeladdition/cyclization reaction of oxoindolines with cyclic 1,3-diketones to afford the chiral spiro-conjugated oxindolesfeaturing 2-aminopyrans fusing with carbo-heterocyclic ringsystems with excellent chemical yields (up to 98%) and enantioselectivities (up to 95% ee). The obtained chiral spiroconjugated 2-aminopyrans bearing quaternary stereogenic carbon center could be used as synthetic precursors for severalnatural products that have a broad spectrum of fascinating biological activities.