Insights into the mechanism of the site-selective sequential palladium-catalyzed cross-coupling reactions of dibromothiophenes/dibromothiazoles and arylboronic acids. Synthesis of PPARβ/δ agonists
Insights into the mechanism of the site-selective sequential palladium-catalyzed cross-coupling reactions of dibromothiophenes/dibromothiazoles and arylboronic acids. Synthesis of PPARβ/δ agonists
The invention is directed to compounds of formula (1)
and pharmaceutically acceptable salts thereof, methods for the preparation thereof, and methods of use thereof.
这项发明涉及公式(1)的化合物及其药用盐,其制备方法和使用方法。
[EN] PESTICIDALLY ACTIVE POLYCYCLIC DERIVATIVES WITH SULFUR SUBSTITUTED FIVE-MEMBERED RING HETEROCYLES<br/>[FR] DÉRIVÉS POLYCYCLIQUES À ACTIVITÉ PESTICIDE À HÉTÉROCYCLES À NOYAU À CINQ CHAÎNONS SUBSTITUÉS PAR DU SOUFRE
申请人:SYNGENTA CROP PROTECTION AG
公开号:WO2016169886A1
公开(公告)日:2016-10-27
Polycyclic derivatives of formula (I) wherein the substituents are as defined in claim 1, and the agrochemically acceptable salts, stereoisomers, enantiomers, tautomers and N-oxides of those compounds, can be used as insecticides and can be prepared in a manner known per se.
Insights into the mechanism of the site-selective sequential palladium-catalyzed cross-coupling reactions of dibromothiophenes/dibromothiazoles and arylboronic acids. Synthesis of PPARβ/δ agonists
作者:Raquel Pereira、Audrey Furst、Beatriz Iglesias、Pierre Germain、Hinrich Gronemeyer、Angel R. de Lera
DOI:10.1039/b612235c
日期:——
A reactivity study, aided by NMR spectroscopy, allowed a mechanistic rationale to be postulated for the palladium-catalyzed regioselective coupling of arylboronic acid (and arylstannane where feasible) at the position next to the sulfur atom in functionalized dibromothiophenes and dibromothiazoles. The analysis of the NMR spectra (using 19F from the boronic acid CF3 group and 31P from the phosphine of the catalyst as probes) of the entire reaction starting from the dibromoheterocycles allowed the qualitative proposal that the transmetalation is the rate-limiting step for both sequential substitution processes. The extremely facile oxidative addition at the CâBr bond next to the sulfur atom of the heterocycle instead determines the positional selectivity. An additional Stille reaction then replaced the second halogen, providing the trisubstituted heterocyclic scaffolds of PPAR ligands, which displayed PPARβ/δ agonist activity, as revealed by reporter assays in living cells.