Oxidant and Transition-Metal-Free Photoinduced Direct Oxidative Annulation of 1-Aryl-2-(furan/thiophen-2-yl)butane-1,3-diones
摘要:
A photoinduced direct oxidative annulation of 1-ary1-2(furan/thiophen-2-yObutane-1,3-diones and ethy1-2-(furan-2-y1)-3-oxo-3(ary1-2-yl)propanoates in EtOH without the need for any transition metals and oxidants provided access to highly functionalized polyheterocyclic 1(5-hydroxynaphtho [2,1-b.] furan-4-y1) ethano ne s and 1- (5-hydroxyfuran/thieno/pyrrolo [3,2-e]benzofuran-4-yl)ethanones. The phenomenon of excited-state intramolecular proton transfer (ESIPT) was observed for both 1-(S-hydroxynaphtho[2,1-b]furan-4-yl)ethanone and 1-(5-hydroxy furan/thieno/pyrrolo [3,2-db enzofuran-4-y1) ethanone analogues.
The silver‐catalyzed oxidative C(sp3)−H/P−H cross‐coupling of 1,3‐dicarbonyl compounds with H‐phosphonates, followed by a chemo‐ and regioselective C(sp3)−C(CO) bond‐cleavage step, provided heavily functionalized β‐ketophosphonates. This novel method based on a readily available reaction system exhibits wide scope, high functional‐group tolerance, and exclusive selectivity.
Pyridazin-3(2H)-one derivatives of formula (I) are found to inhibit PDE-4. R
1
, R
2
and R
4
are organic radicals, R
3
is a cyclic group, and R
5
is an ester or an aryl or heteroaryl group.
Pyridazin-3(2H)-one derivatives of formula (I) are found to inhibit PDE-4:
wherein
R
1
, R
2
and R
4
are organic radicals, R
3
is a cyclic group, and R
5
is an ester or an aryl or heteroaryl group.
In this work, the use of N-acyloxybenzamides as efficient acyl nitrene precursors under photoredox/iron dual catalysis is reported. The resulting acyl nitrenes could be captured by various types of C–H bonds and S- or P-containing molecules. Mechanism investigations suggested that the formation of the acyl nitrene from the N-acyloxybenzamide occurs by a photoredox process, and it is believed that in
在这项工作中,报道了在光氧化还原/铁双重催化下使用N-酰氧基苯甲酰胺作为有效的酰基氮烯前体。由此产生的酰基氮烯可以被各种类型的 C-H 键和含 S 或 P 的分子捕获。机理研究表明,由N-酰氧基苯甲酰胺形成酰基氮烯是通过光氧化还原过程发生的,并且认为在该氧化还原过程中,N-酰氧基苯甲酰胺的氧化 N-H 键断裂发生在还原性 N-O 键断裂之前N-酰氧基苯甲酰胺。