Regioselectivity-Reversed Asymmetric Aldol Reaction of 1,3-Dicarbonyl Compounds
摘要:
Reverse regioselectivity: The first catalytic asymmetric C-1 functionalization of 1,3-dicarbonyl compounds by an aldol reaction is described, which regioselectively affords 6-hydroxyhexane-2,4-dione derivatives as the only product with high optical purity of up to 93 % ee. Furthermore, this method provides a facile access to enantioenriched oxygen-containing spirooxindoles and spirobutyrolactones from simple commercial available starting materials (see scheme).
Protecting group-directed annulations of tetra-substituted oxindole olefins and sulfur ylides: regio- and chemoselective synthesis of cyclopropane- and dihydrofuran-fused spirooxindoles
作者:Jing-Wen Kang、Xiang Li、Fei-Yu Chen、Yuan Luo、Shu-Cang Zhang、Bin Kang、Cheng Peng、Xu Tian、Bo Han
DOI:10.1039/c9ra02192b
日期:——
Protecting group-controlled annulations of tetra-substituted oxindole olefins and sulfur ylides have been achieved for the synthesis of multifunctional cyclopropane- and dihydrofuran-fused spirooxindoles. Under precise annulation regulation, a variety of cyclopropane- and dihydrofuran-fused spirooxindoles containing vicinal quaternary carbon centers were produced in up to 90% yield with up to 20 : 1
已经实现了四取代羟吲哚烯烃和硫叶立德的保护基控制环化,用于合成多功能环丙烷和二氢呋喃稠合螺羟吲哚。在精确的环化调节下,以高达 90% 的产率和高达 20 : 1 的 dr. 该反应表现出高区域、化学和非对映选择性、广泛的官能团耐受性和克级容量。
Hydrolytic Degradation of Some Fused and Spiro Compounds Containing a System of 2-Amino-3-Cyano-4H-Pyran
作者:A. N. Andin
DOI:10.1134/s1070428018050251
日期:2018.5
Heating some derivatives of 5,6,7,8-tetrahydro-4Н-chromene and 1,2,5′,6′,7′,8′-hexahydrospiro-[indole-3,4′-chromene] in acid environment causes a hydrolytic degradation with the formation of functionally substituted carboxylic acids. A derivative of 1,2-dihydrospiro[indole-3,4′-pyran] in the same conditions afforded a mixture of products resulting from retro-Michael decomposition and recyclization
Mn(III)-based radical addition reactions of 2-nitroindole with activated CH compounds
作者:Dmitry A. Androsov、Tara L.S. Kishbaugh、Gordon W. Gribble
DOI:10.1016/j.tetlet.2008.09.020
日期:2008.11
2-Nitroindole undergoes addition reactions with the radicals generated from active CH compounds upon treatment with Mn(OAc)(3)center dot 2H(2)O to afford the corresponding 3-substituted-2-nitroindoles in 27-66% yields. Products of the methylene addition reactions undergo a subsequent in situ Nef reaction to afford 2-oxoindolin-3-ylidenes. (C) 2008 Elsevier Ltd. All rights reserved.