title: N-heterocyclic carbene catalyzed reaction of phthalaldehydes: controllable stereoselective synthesis of polyhydroxylated spiro- and fused indenones dictated by the structure of NHC catalysts.
abstract: The N-heterocyclic carbene catalyzed stereoselective dimerization reactions of phthalaldehydes produced polyhydroxylated spiro- or fused indenones. The reaction pathways were dictated by the structures of NHC catalysts. Under the catalysis of a imidazole carbene, phthalaldehydes produced dihydroxylspiro[indene-2,1'-isobenzofuran]-3-ones in good to excellent yields, whereas a triazole carbene catalyzed reaction of phthalaldehydes afforded fully cis-trihydroxylindeno[2,1-a]inden-5-ones in high yields. This work not only provides a highly efficient method for the construction of valuable polyhydroxyl substituted indene derivatives that are not easily assembled by other synthetic means but also reflects the versatility of organocatalysis using N-heterocyclic carbenes.
authors.affiliation: College of Chemistry, Beijing Normal University, Beijing 100875, China. ycheng2@bnu.edu.cn
authors.forename: Ying
authors.initials: Y
authors.lastname: Cheng
authors.forename: Jiang-Hua
authors.initials: JH
authors.lastname: Peng
authors.forename: Yong-Jia
authors.initials: YJ
authors.lastname: Li
authors.forename: Xun-Yu
authors.initials: XY
authors.lastname: Shi
authors.forename: Ming-Sheng
authors.initials: MS
authors.lastname: Tang
authors.forename: Tian-Yu
authors.initials: TY
authors.lastname: Tan