An unprecedented reaction between indolin-2-ones and α-substituted ketones has been developed. Using this protocol, a wide range of biologically important 3-hydroxy-3-phenacyloxindole derivatives could be obtained in good yield (up to 93%) under mild reaction conditions. A possible mechanism of this reaction was tentatively proposed based on some control experiments and MS spectrometry analysis.
B(C<sub>6</sub>F<sub>5</sub>)<sub>3</sub>-Catalyzed Direct C3 Alkylation of Indoles and Oxindoles
作者:Shyam Basak、Ana Alvarez-Montoya、Laura Winfrey、Rebecca L. Melen、Louis C. Morrill、Alexander P. Pulis
DOI:10.1021/acscatal.0c01141
日期:2020.4.17
The direct C3 alkylation of indoles and oxindoles is a challenging transformation, and only a few direct methods exist. Utilizing the underexplored ability of triaryl boranes to mediate the heterolytic cleavage of α-nitrogen C–H bonds in amines, we have developed a catalytic approach for the direct C3 alkylation of a wide range of indoles and oxindoles using amine-based alkylating agents. We also employed
作者:P. Caramella、A. Coda Corsico、A. Corsaro、D. Del Monte、F. Marinone Albini
DOI:10.1016/0040-4020(82)85063-1
日期:1982.1
Cycloadditions of benzonitrile oxide and mesitonitrile oxide to N-methylindole and indole yield the acid sensitive cycloadducts 1 a-d with high regioselectivity. With N-carbethoxyindole the stable cycloadducts 1 e,f and minor amounts of the regioisomeric 2 e,f are isolated. The electron withdrawing substituent reduces both the regioselectivity and the reactivity of the cycloadditions.
A novel bifunctionalthioureacatalyzed formal [5 + 1] cycloaddition of oxindoles and ester-linked bisenones was successfully developed. This strategy involves two sequential Michael additions, leading to spirooxindole δ-lactones with three contiguous stereocenters including an all-carbon quaternary center with high diastereo- and enantioselectivites. In addition, a remarkable N-substituent effect