1222406-75-8Relevant academic research and scientific papers
Diastereoselective Intramolecular Aldol-Type Trapping of Zwitterionic Intermediates by Ketones for the Synthesis of Spiro[chroman-4,3′-oxindole] Derivatives
Jia, Shikun,Lei, Yubing,Song, Longlong,Krishna Reddy, A. Gopi,Xing, Dong,Hu, Wenhao
, p. 58 - 63 (2017)
A simple, mild and efficient rhodium-catalyzed aromatic C–H functionalization of α-phenoxy ketones by 3-diazooxindoles for the synthesis of the spiro[chroman-4,3′-oxindole] ring system is described. A series of functionalized spiro[chroman-4,3′-oxindole] derivatives bearing two adjacent quaternary carbon centers have been attained in a highly diastereoselective manner with very good yields. Control experiments suggested the possibility of an intramolecular aldol-type trapping of zwitterionic intermediates after the C–H functionalization. Furthermore, the applicability of this method has been tested by a gram-scale synthesis. A facile treatment with base enabled the access to both syn- and anti-diastereomers via isomerization. (Figure presented.).
AZO DYES, A PROCESS FOR THE PREPARATION THEREOF AND THE USE THEREOF
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Page/Page column 9, (2010/05/13)
The present invention relates to dyes of formula (I) wherein R1 and R2 are each independently of the other hydrogen, vinyl, allyl or C1-C6alkyl which is unsubstituted or substituted by cyano, carboxy, hydroxy, C
