various biarylcarboxylic acids via photoredox catalysis. Attractive features of this process include generation of acyl radical, which quickly underdone intramolecular radical cyclization. This method marks the first photocatalytic intramolecular acyl radical coupling for constructing carbon–carbon bond, which further synthesizes the valuable fluorenone products with mild conditions, good yields, and
An efficient and robust methodology based on electrochemical techniques for the direct synthesis of aromatic lactones through dehydrogenative C−O cyclization is described. This new and useful electrochemical reaction can tolerate a variety of functional groups, and is scalable to 100 g under mild conditions. Remarkably, heterocycle‐containing substrates can be employed, thus expanding the scope of
Cerium photocatalyzed dehydrogenative lactonization of 2-arylbenzoic acids
作者:Ketan Wadekar、Suraj Aswale、Veera Reddy Yatham
DOI:10.1039/c9ob02676b
日期:——
The first cerium photocatalyzed dehydrogenative lactonization of 2-arylbenzoic acids has been developed. This operationally simple protocol allows rapid access to synthetically useful coumarins on gram scale by employing CeCl3 as a photocatalyst and O2 as a terminal oxidant. Overall, this delivers an economical and environmentally amiable entry to diversely substituted coumarins, important structural
A practical, electrochemical method is developed for the direct dehydrogenative lactonization of C(sp2/sp3)–H bonds under external oxidant- and metal-free conditions, delivering diverse lactones, including coumarin derivatives with excellent regioselectivity. The scalable nature of this newly developed electrochemical process was demonstrated on a 40 g scale following an operationally simple protocol