Microwave-Promoted, One-Pot, Solvent-Free Synthesis of 4-Arylcoumarins from 2-Hydroxybenzophenones
作者:José Crecente-Campo、M. Pilar Vázquez-Tato、Julio A. Seijas
DOI:10.1002/ejoc.201000051
日期:2010.7
4-Arylcoumarins are synthesized in very good yields through solvent-free microwave irradiation of 2-hydroxybenzophenones and alkyl malonate in the presence of DBU. The one-pot synthesis is carried out with Knoevenagel condensation, intramolecular lactonization, and decarboxylation reactions. The method can be applied to a broad scope of neoflavonoids.
A variety of functionalized coumarins were synthesized from substituted phenylacrylic acids via PIDA/I2-mediated and irradiation-promoted oxidative carbon–oxygen bond formation. Our studies show that the oxygen in the pendant carboxylic acid group cyclizes favorably to the aryl ring that is cis to it. The main advantages of this method include good functional group tolerance and the transition-metal-free
通过PIDA / I 2介导的和辐射促进的氧化碳-氧键形成,由取代的苯基丙烯酸合成了多种功能化的香豆素。我们的研究表明,羧酸侧基中的氧有利地环化成顺式的芳基环。该方法的主要优点包括良好的官能团耐受性和无过渡金属的特性。
Visible-light-driven site-selective alkylation of the benzo core of coumarins
作者:Krishna N. Tripathi、Shashank Singh、Naved Akhtar、Kuntal Manna、Ravi P. Singh
DOI:10.1039/d2cc03073j
日期:——
An unprecedented, straightforward photochemical platform for efficient site-selective C–H alkylation of the C7 position of the benzocore via the cross coupling between coumarins and NHPI esters, employing Ru(II) as a photocatalyst in visiblelight, has been reported. Remarkably, this transformation demonstrated broad substrate scope and good functional group compatibility. Controlled experiments and