Asymmetric [3+2] Cycloaddition of Olefins with Morita–Baylis–Hillman Carbonates Catalyzed by BINOL-Based Bifunctional Phosphine
作者:Hai-Lei Cui、Xue Tang、Meng-Fan Li、Xing-Jie Xu、Yin Shi
DOI:10.1055/s-0037-1611752
日期:2019.4
series of novel BINOL-based phosphines. These bifunctional organocatalysts can be used in the [3+2] cycloaddition of electron-deficient olefins and Morita–Baylis–Hillman (MBH) carbonates. Moderate to excellent yields (up to >99%) and good to excellent enantioselectivities (up to 95% ee) can be obtained in the cycloaddition reaction of maleimides and MBH carbonates. The application of these novel phosphines
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
Chiral Lewis bases facilitated the synthesis of highly functionalized spirooxindoles containing α-exo-methylene-γ-butyrolactones in high yields (76–92 %) and excellent enantioselectivities (up to 98 % ee) at ambient temperature.
Pentaenolate activation in the organocatalytic allylic alkylation of indene-2-carbaldehydes
作者:Adam Cieśliński、Sebastian Frankowski、Łukasz Albrecht
DOI:10.1039/d3cc00900a
日期:——
this manuscript, the application of pentaenolate intermediates in the allylic alkylation of indene-2-carbaldehydes with Morita–Baylis–Hillman (MBH) carbonates is described. The reaction has been carried out in a highly enantio- and diastereoselective manner due to the use of a chiral tertiary amine as a nucleophilic catalyst. The developed reactivity constitutes the first application of organocatalytic
The enantioselective fluoromalonate addition to Morita-Baylis-Hillman carbonates is presented. The reaction is simply catalyzed by beta-isocupreidine affording the final fluorinated products in good yields and enantioselectivities. (C) 2012 Elsevier Ltd. All rights reserved.