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Chiral N‐Heterocyclic Carbene‐Catalyzed Asymmetric Michael–Intramolecular Aldol‐Lactonization Cascade for Enantioselective Construction of β‐Propiolactone‐Fused Spiro[cyclopentane‐oxindoles]
Author(s) -
Zhang JunQi,
Li NaiKai,
Yin ShaoJie,
Sun BingBing,
Fan WeiTai,
Wang XingWang
Publication year - 2017
Publication title -
advanced synthesis and catalysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.541
H-Index - 155
eISSN - 1615-4169
pISSN - 1615-4150
DOI - 10.1002/adsc.201601259
Subject(s) - cyclopentane , chemistry , stereocenter , carbene , aldol reaction , intramolecular force , enantioselective synthesis , catalysis , stereochemistry , cascade , asymmetric carbon , organocatalysis , organic chemistry , optically active , chromatography
A cascade asymmetric Michael–intramolecular aldol‐lactonization of enals with oxindolyl β,γ‐unsaturated α‐keto esters was developed. An optically pure aminoindanol‐derived triazolium‐based N‐heterocyclic carbene was used as the catalyst. The corresponding desired β‐propiolactone‐fused spiro[cyclopentane‐oxindoles] were obtained in moderate yields with excellent diastereoselectivities and enantioselectivities. Notably, the obtained enantio‐enriched highly functionalized complex molecules contain four contiguous stereocenters, including a spiro all‐carbon center and a quaternary carbon center.