A C–H Borylation Approach to Suzuki–Miyaura Coupling of Typically Unstable 2–Heteroaryl and Polyfluorophenyl Boronates
摘要:
A method for the synthesis of biaryls and heterobiaryls from arenes and haloarenes without the intermediacy of unstable boronic acids is described. Pinacol boronate esters that are analogous to unstable boronic acids are formed in high yield by iridium-catalyzed C-H borylation of heteroarenes and fluoroarenes. These boronates are stable in the solid state or in solution and can be generated and used in situ. They couple with aryl halides in the presence of simple palladium catalysts, providing a convenient route to biaryl and heteroaryl products that have been challenging to prepare via boronic acids.
An efficient phosphine-free direct C–Harylation of thiophenes at the α-position has been developed at low catalyst loading of bis(alkoxo)palladium complex (Cat.I, 0.1–0.2 mol %). The developed synthetic method can be applied to the synthesis of α-aryl/heteroaryl thiophenes from aryl or heteroaryl bromides in good to excellent yields and is compatible with the substrates bearing electron-donating or
Ligand-less palladium-catalyzed direct 5-arylation of thiophenes at low catalyst loadings
作者:Julien Roger、Franc Požgan、Henri Doucet
DOI:10.1039/b819912d
日期:——
Ligand-less Pd(OAc)2 provides a very efficient catalyst for the direct5-arylation of thiophenederivatives. With this catalyst, a low palladium concentration (0.1–0.001 mol%) should be employed in order to obtain high yields of coupling products. At higher concentrations a fast formation of inactive “Pd black” generally occurs. Substrates/catalysts ratios up to 100000 can be employed with the most
PHENYL C-GLUCOSIDE DERIVATIVES, PREPARATION METHODS AND USES THEREOF
申请人:Zhao Guilong
公开号:US20130023486A1
公开(公告)日:2013-01-24
The present invention relates to a sodium glucose cotransporter 2 (SGLT2) inhibitor with a phenyl C-glucoside structure, its preparation method, a pharmaceutical composition containing the same, and its use in treating diabetes and preparing an anti-diabetes medicament. The invention provides a compound with the structure of general formula I and a pharmaceutically acceptable salt and prodrug ester thereof,
wherein, the definitions of R
5
and R
6
are selected from the following:
(1) R5=R6=Me; (2) R5=Me, R6=OMe; (3) R5=Me, R6=H; (4) R5=Me, R6=F; (5) R5=F, R6=H; and (6) R5=OMe, R6=H.