The iron-catalyzed cross-dehydrogenative coupling (CDC) of C(sp3)–H/C(sp3)–H bonds to afford olefins by 4H elimination is described. This method employs air (molecular oxygen) as an ideal oxidant, and is performed under mild, ligand-free and base-free conditions. H2O is the only byproduct. Good tolerance of functional groups and high yields have also been achieved. Preliminary mechanistic investigations
Organocatalytic Enantioselective Synthesis of Polysubstituted Spirooxindoles using a Tandem Michael-Michael Reaction
作者:Santhi Abbaraju、Naresh Ramireddy、Nirmal K. Rana、Hadi Arman、John C.-G. Zhao
DOI:10.1002/adsc.201500298
日期:2015.8.24
A highly efficient stereoselective method for the synthesis of functionalized spirooxindole derivatives with four contiguous stereogenic centers, including two adjacent quaternary stereogenic centers, was realized through an organocatalytic tandem Michael–Michael reaction. By employing a quinidine‐derived thiourea organocatalyst, the reaction between (E)‐2‐cyano‐2‐(2‐oxo‐1‐tritylindolin‐3‐ylidene)acetates
Phosphorus-containing Lewis base catalyzed highly regioselective cyclization of isatin derived electron-deficient alkenes with but-3-yn-2-one
作者:Zhong Lian、Yin Wei、Min Shi
DOI:10.1016/j.tet.2012.01.036
日期:2012.3
In this paper, we reported that phosphorus-containing Lewis bases catalyzed [4+2] cyclization of N-protected isatin derived electron-deficient alkenes with but-3-yn-2-one could proceed smoothly to give the corresponding dihydropyrano[2,3-b]indoles in good to excellent yields under mild conditions. The substrate scope has been carefully examined and the plausible reaction mechanism has been also proposed. (C) 2012 Elsevier Ltd. All rights reserved.
Synthesen mit Nitrilen, 88. Mitt.: Spiro[indol- und Spiro[inden-pyrano[2,3-c]pyrazole]aus Cyanmethylenderivaten und Pyrazolonen
作者:Renate Dworczak
DOI:10.1007/bf00811473
日期:——
The reactivity of cyanomethylene-indolones (1 a-e) and 2-(dicyanomethylene)-indan-1,3-dione (4) towards, 1,5-disubstituted 3-pyrazolones (2 a-c) was investigated. The reactions yield spiro[indene- and spiro[indole-4'- and 6'-pyrano[2,3-c]pyrazoles] (3 a-e, 5 a-c). The structures are proven by C-13-NMR-spectroscopy. The mechanisms of the reactions are discussed.
Copper-catalyzed hydroboration of alkenyl oxindoles
作者:Maria Eduarda Contreira、Diogo S. Lüdtke、Angélica V. Moro
DOI:10.1016/j.tetlet.2018.06.009
日期:2018.7
Herein we describe the NHC-Cu(I)-catalyzed hydroboration of alkenyl oxindoles. The corresponding boronates were obtained in good yields, under operationally simple and environmentally friendly conditions, using ethanol as the solvent. Our studies revealed that water-based systems were not very effective. Furthermore, the obtained products are amenable to further elaboration and can be useful to the