expedient method was demonstrated for the synthesis of 3‐alkenyl‐3‐amino‐2‐oxindoles from readily available propargylic alcohols and isatin imines in the presence of BF3 ⋅ Et2O as a catalyst under open‐air atmosphere. The above reaction was time‐dependent and further extended to the one‐pot synthesis of highly substituted spiro‐indeneindolones via 1,3‐amino group migration/Friedel‐Crafts cyclization. This
α-Selective Allylation of Isatin Imines Using Metallic Barium
作者:Akira Yanagisawa、Seiya Yamafuji、Toshiki Sawae
DOI:10.1055/s-0035-1561450
日期:——
Barbier-type allylation of isatin imines with allylicchlorides was achieved by using metallic barium as the promoter. Various α-allylated 3-amino-2-oxindoles were synthesized from the corresponding allylicchlorides and isatin imines. The double-bond geometry of allylicchlorides was retained throughout the reaction. An arylic bromide or iodide functionality of the products was robust to metalation under the
Control of N-Heterocyclic Carbene Catalyzed Reactions of Enals: Asymmetric Synthesis of Oxindole-γ-Amino Acid Derivatives
作者:Xiang-Yu Chen、Jia-Wen Xiong、Qiang Liu、Sun Li、He Sheng、Carolina von Essen、Kari Rissanen、Dieter Enders
DOI:10.1002/anie.201708994
日期:2018.1.2
A strategy to control the switch between a non‐cycloaddition reaction and a cycloaddition reaction of enals, using N‐heterocyclic carbene (NHC) catalyisis, has been developed. The new scalable protocol leads to γ‐amino‐acid esters bearing a tetrasubstituted stereocenter in good yields and high stereoselectivities by homo‐Mannich reactions of enals and isatin‐derived ketimines. By simply changing the
Catalytic asymmetric Povarov reaction of isatin-derived 2-azadienes with 3-vinylindoles
作者:Hong-Hao Zhang、Xiao-Xue Sun、Jing Liang、Yue-Ming Wang、Chang-Chun Zhao、Feng Shi
DOI:10.1039/c4ob01741b
日期:——
The first catalytic asymmetric Povarov reaction of isatin-derived 2-azadienes with 3-vinylindoles was established in the presence of chiral phosphoric acid, which tolerates a wide range of substrates with generally excellent diastereoselectivity and good enantioselectivity (up to >95 : 5 dr, 89 : 11 er). This approach will greatly enrich the chemistry of the catalytic asymmetric Povarov reaction, in particular ketone-involved transformations. Furthermore, this protocol represents the first diastereo- and enantio-selective construction of a spiro[indolin-3,2′-quinoline] framework bearing an indole moiety. This novel type of spiro-compound not only contains two chiral centers, including one quaternary stereogenic center, but also integrates two biologically important structures of spiro[indolin-3,2′-quinoline] and indole, which may find medicinal applications after bioassay.
Dual Behavior of Isatin-Based Cyclic Ketimines with Dicarbomethoxy Carbene: Expedient Synthesis of Highly Functionalized Spirooxindolyl Oxazolidines and Pyrrolines
作者:T. Rajasekaran、G. Karthik、B. Sridhar、B. V. Subba Reddy
DOI:10.1021/ol400287q
日期:2013.4.5
devised for the synthesis of a wide range of spirooxindolyl oxazolidines via an intermolecular 1,3-dipolarcycloaddition of carbonyl ylides generated from dimethyl diazomalonate and aromatic aldehydes, with cyclic ketimines using 5 mol % of Rh2(OAc)4 under mild conditions. Similarly, highly functionalized spirooxindolyl pyrrolines have also been prepared through1,3-dipolarcycloaddition of azomethine