Efficient Entry to Diversely Functionalized Spirocyclic Oxindoles from Isatins through Carbonyl-Addition/Cyclization Reaction Sequences
摘要:
A novel approach to diversely functionalized spirocyclic oxindoles has been developed by using different metal-mediated carbonyl-addition/cyclization reaction sequences. Spirocyclization precursors, 2-indolinonetethered homoallylic alcohols, (buta-1,3-dien-2-yl)methanols, and alpha-allenols have been obtained by regioselective addition of stabilized organoindium reagents to isatins in aqueous environment. Ruthenium-, silver-, and palladium-catalyzed reactions of the above unsaturated alcohol derivatives provided oxaspiro oxindoles.
N-Heterocyclic Carbene Catalyzed Generation and [4+2] Annulation of Unsubstituted Dienolate - Enantioselective Synthesis of Spirocyclic Oxindolodihydropyranones
作者:Jin-Tang Cheng、Xiang-Yu Chen、Zhong-Hua Gao、Song Ye
DOI:10.1002/ejoc.201403395
日期:2015.2
The N-heterocycliccarbenecatalyzed (NHC-catalyzed) generation of unsubstituted dienolate (butadienolate) and subsequent [4+2] annulation reactions with isatins afford chiral spirocyclic oxindolodihydropyranones in moderate to good yields with moderate to good enantioselectivities.