N-Heterocyclic Carbene Catalyzed Reaction of Phthalaldehydes: Controllable Stereoselective Synthesis of Polyhydroxylated Spiro- and Fused Indenones Dictated by the Structure of NHC Catalysts
摘要:
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.
<i>N</i>-Heterocyclic Carbene Catalyzed Reaction of Phthalaldehydes: Controllable Stereoselective Synthesis of Polyhydroxylated Spiro- and Fused Indenones Dictated by the Structure of NHC Catalysts
作者:Ying Cheng、Jiang-Hua Peng、Yong-Jia Li、Xun-Yu Shi、Ming-Sheng Tang、Tian-Yu Tan
DOI:10.1021/jo102582a
日期:2011.3.18
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.
Synthesis of Spiro Bis-Indanes via Domino Stetter-Aldol-Michael and Stetter-Aldol-Aldol Reactions: Scope and Limitations
The synthesis of spiro bis-indanes by means of N-heterocyclic carbene (NHC) catalysis is reported. The dimerization of various o-formylchalcone substrates or their combination with phthaldialdehyde derivatives under the catalysis of thiazolium-derived carbenes afforded Stetter-aldol-Michael products and Stetter-aldol-aldol products, respectively. The use of poor Michael acceptors in conjunction with