Highly Enantioselective [3+2] Annulation of Morita-Baylis-Hillman Adducts Mediated by L-Threonine-Derived Phosphines: Synthesis of 3-Spirocyclopentene-2-oxindoles having Two Contiguous Quaternary Centers
作者:Fangrui Zhong、Xiaoyu Han、Youqing Wang、Yixin Lu
DOI:10.1002/anie.201102094
日期:2011.8.16
Spiral bound: The Morita–Baylis–Hillmanadducts were employed as C3 synthons in the asymmetric [3+2] annulation with malonitrile substrates using L‐threonine‐derived 1 as the catalyst (see scheme). The reaction is highly regioselective and stereoselective, and affords optically enriched 3‐spirocyclopentene‐2‐oxindoles containing twocontiguousquaternarycenters. Boc=tert‐butoxycarbonyl, PMB=para‐methoxybenzyl
Pd(II)/β-ICD-Cocatalyzed Asymmetric Route to Oxindole Scaffold via Cascade Reaction of Diazoacetamides and MBH-Carbonates
作者:Yang Yang、Chaoqun Ma、Nilesh J. Thumar、Wenhao Hu
DOI:10.1021/acs.joc.6b01703
日期:2016.9.16
report an efficient method for asymmetricsynthesis of chiral oxindoles. Allyl palladium(II) chloride dimer (APC)-catalyzed, in combination with β-isocupreidine (β-ICD)-cocatalyzed, reaction of diazoacetamide with Morita–Baylis–Hillman (MBH) carbonates proves to be a facile protocol to access multifunctional oxindoles bearing a C-3 quaternary stereo center. This tandem reaction tolerates a wide variety of