Remote Control of Axial Chirality: Synthesis of Spirooxindole-Urazoles via Desymmetrization of ATAD.
Lin-Lin ZhangJi-Wei ZhangShao-Hua XiangZhen GuoBin TanPublished in: Organic letters (2018)
For the first time, a desymmetrization strategy empowered the assembly of a class of optically pure spirooxindole-urazoles possessing an N-Ar stereogenic axis via remote control of axial chirality in an asymmetric three-component reaction. This transformation was realized by a tandem bisthiourea-catalyzed asymmetric Diels-Alder reaction and substrate-controlled asymmetric ene reaction. The driving force derived from aromatization and the high reactivity of 4-aryl-1,2,4-triazole-3,5-dione enophiles mediated the occurrence of the successive ene reaction under mild conditions.
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