292851-47-9Relevant academic research and scientific papers
Phosphine-catalyzed enantioselective γ-addition of 3-substituted oxindoles to 2,3-butadienoates and 2-butynoates: Use of prochiral nucleophiles
Wang, Tianli,Yao, Weijun,Zhong, Fangrui,Pang, Guo Hao,Lu, Yixin
supporting information, p. 2964 - 2968 (2014/04/03)
The first phosphine-catalyzed enantioselective γ-addition with prochiral nucleophiles and 2,3-butadienoates as the reaction partners has been developed. Both 3-alkyl- and 3-aryl-substituted oxindoles could be employed in this process, which is catalyzed by a chiral phosphine that is derived from an amino acid, thus affording oxindoles that bear an all-carbon quaternary center at the 3-position in high yields and excellent enantioselectivity. The synthetic value of these γ-addition products was demonstrated by the formal total synthesis of two natural products and by the preparation of biologically relevant molecules and structural scaffolds.
An approach to some spiro oxindole alkaloids through cycloaddition reactions of 3-methylideneindolin-2-one
Bell, Stephanie E. V.,Brown, Roger F.C.,Eastwood, Frank W.,Horvath, Julianna M.
, p. 183 - 190 (2007/10/03)
3-Methylideneindolin-2-one (3-methylideneoxindole) (1) was prepared in 60-89% yield by flash vacuum pyrolysis of the acetate or methyl carbonate of 3-hydroxy-3-methylindolin-2-one, and was fully characterized, but application of the same procedure to 3-hydroxy-5-methoxyindolin-2-one did not give useful yields. Cycloaddition reactions of CH2=+NR-CH2- and of the related ylide (25) (from 1-(trimethylsilylmethyl)piperidine-2-carbonitrile and AgF) to 3-methylideneindolin-2-one (1) gave 4-20% yields of spiro oxindoles, but yields were markedly below those achieved in cycloadditions to the more electrophilic N-phenylmaleimide (70-79%). Attempted alkylation of weakly basic secondary amines, e.g. piperidine-2-carbonitrile, with Me3SiCH2Cl in dimethyl sulfoxide/K2CO3 gave only carbamates Me3SiCH2OOCNR2. CSIRO 2000.
