Ruthenium(II)-Catalyzed Oxidative Double C–H Activation and Annulation Reaction: Synthesis of Indolo[2,1-<i>a</i>]isoquinolines
作者:Somadrita Borthakur、Bipul Sarma、Sanjib Gogoi
DOI:10.1021/acs.orglett.9b02871
日期:2019.10.4
The first metal-catalyzed double aryl C(sp2)-H bond activation of antipyrine and alkyne annulation reaction is reported. This Ru(II)-catalyzed reaction was accomplished in the presence of 20 mol % phosphine ligand tricyclohexylphosphine tetrafluoroborate to afford indolo[2,1-a]isoquinolines that are very important compounds because of their bioactivity and interesting optical properties.
Compounds are disclosed which are 4-amino-2,3-di-substituted-1-(mono- or trichlorophenyl)-3-pyrazolin-5-ones represented by the following formulae (1) to (3): ##STR1## and acid addition salts thereof. The compounds can be easily produced and are useful for qualitative analysis or quantitative analysis of hydrogen peroxide when used as a component of a color indicator composition for detecting hydrogen peroxide.
Room-Temperature Direct Alkenylation of 5-Pyrazolones
作者:Yiwen Yang、Hao Gong、Chunxiang Kuang
DOI:10.1002/ejoc.201300765
日期:2013.8
A mild and efficient method for the directalkenylation of 5-pyrazoles by Pd-catalyzed C–H bond activation is described. The reaction smoothly proceeds at room temperature to provide products in up to 92 % yield.
Ruthenium‐ and silver‐catalyzed selective C–Halkenylations, thiolations and selenylations of phenazone (antipyrine) – a non‐steroidal anti‐inflammatory drug – have been developed. This method features ample substrate scope, affording typically the mono‐ortho alkenylated, thiolated and selenylated products in good yields with complete site selectivity control. This strategy offers an efficient protocol
A mild, efficient and catalytic ligand-free method for the direct arylation of 5-pyrazolones by Pd-catalyzed C-H bond activation is reported. The process smoothly proceeds and yields are moderate to excellent.