remote cross Rauhut−Currier reaction utilizing vinyl ketones and para‐quinone methides derived from isatins was realized, which was successfully catalyzed using bifunctional phosphines, furnishing chiral 3,3‐disubstituted oxindoles in excellent enantioselectivities and high yields. The mechanistic studies demonstrated the key role of the alkyl hydrogen of the vinyl ketones, which conceivably interacted
Enantioselective Copper-Catalyzed [3 + 3] Cycloaddition of Tertiary Propargylic Esters with 1<i>H</i>-Pyrazol-5(4<i>H</i>)-ones toward Optically Active Spirooxindoles
作者:You-Wei Xu、Ling Li、Xiang-Ping Hu
DOI:10.1021/acs.orglett.0c03587
日期:2020.12.18
A copper-catalyzed enantioselective [3 + 3] cycloaddition of 3-ethynyl-2-oxoindolin-3-yl acetates with 1H-pyrazol-5(4H)-ones for the construction of optically active spirooxindoles bearing a spiro all-carbon quaternarystereocenter has been realized. With a combination of Cu(OTf)2 and chiral tridentate ketimine P,N,N-ligand as the catalyst, the reaction displayed broad substrate scopes, good yields
Organocatalytic Asymmetric Synthesis of
<i>α</i>
‐Trifluoromethyl Homoallylic Amine Derivatives from Trifluoromethyl‐Containing Ketoimines and Isatin‐Derived Morita‐Baylis‐Hillman Carbonates
作者:Danna Chen、Yabo Deng、Shuo Sun、Pengfei Jia、Jinqi Huang、Wenjin Yan
DOI:10.1002/adsc.202201091
日期:2023.1.24
γ-regioselective-alkylation reaction which is catalyzed by a chiraltertiaryamine ((DHQ)2PHAL) and takes advantage of isatin-derived Morita-Baylis-Hillman carbonates and CF3-contained ketoimines, delivered chiral α-trifluoromethylamine derivatives and incorporated an oxindole motif in yields of 65–98%, diastereoselectivities (>20:1 in most cases) and enantioselectivities of 73–99%. The subsequent deprotection
Facile Approach for the Oxidative Enolate Activation of Aliphatic Aldehydes
作者:Qian Liu、Kunpeng Teng
DOI:10.1021/acs.joc.2c02821
日期:2023.2.17
catalytic strategy is developed for the oxidative enolate activation of aliphatic aldehydes. A broad scope of electrophiles including oxindole-derived pyrazolones, oxindole-derived α,β-unsaturated esters, and α,β-unsaturated imines are effective as the reactants in the asymmetric [2 + 4] cycloaddition reaction with the alkyl aldehydes bearing different substitution patterns. Structural complex multicyclic chiral
A highlydiastereo- and enantioselective cascade annulation reaction of Morita–Baylis–Hillman (MBH) maleimides of isatins with ortho-hydroxychalcones was achieved by a chiral N,N′-dioxide/Mg(II) complex Lewis acid catalyst. This strategy provides a concise and efficient route to densely functionalized spiro[cyclopentane-1,3′-oxindole] compounds with five consecutive stereocenters. The reaction itself