Diacylation of coumarins by silver-catalyzed decarboxylative cross-coupling
作者:Hua Wang、Shi-Liu Zhou、Li-Na Guo、Xin-Hua Duan
DOI:10.1016/j.tet.2014.12.029
日期:2015.1
A mild silver-catalyzeddecarboxylative acylation of coumarins has been developed by using α-oxocarboxylicacids as acyl sources. This protocol provides an efficient and straightforward access to aroyl substituted coumarins in moderate to excellent yields with good selectivities. Furthermore, the reaction conditions were also applicable to quinolinones and naphthoquinones, affording the corresponding
An expedient route to highly functionalized 2H-chromene-2-thiones via ring annulation of β-oxodithioesters catalyzed by InCl3 under solvent-free conditions
作者:Rajiv Kumar Verma、Girijesh K. Verma、Keshav Raghuvanshi、Maya Shankar Singh
DOI:10.1016/j.tet.2010.11.055
日期:2011.1
A convenient and one-pot synthesis of 3-aroyl/heteroaroyl-2H-chromene-2-thiones and benzo[f]2H-chromene-2-thiones has been developed by the condensation of β-oxodithioesters and salicylaldehydes/α-hydroxynaphthaldehydes in the presence of indium trichloride under solvent-free conditions. The reaction is operationally facile, readily scalable, and offers rapid entry into differentially substituted chromene-2-thione
通过β-氧代二硫代酯与水杨醛/α-的缩合反应,开发出了一种方便的一锅合成3-芳酰基/杂芳酰基-2 H-亚甲基-2-硫酮和苯并[ f ] 2 H-亚甲基-2-硫酮的方法。在无溶剂条件下在三氯化铟存在下生成羟基萘醛。该反应操作简便,易于扩展,可快速进入差异取代的亚甲基-2-硫酮骨架。
Dual Role of Oxoaldehydes: Divergent Synthesis of 3-Aryl- and 3-Aroylcoumarins
arylation and aroylation of coumarins with glyoxals in a metal-free manner is presented. The aryl glyoxal is for the first time recognized to serve as an aryl surrogate in addition to its role as an aroyl transfer reagent via a simple switch in reaction conditions. The approach accommodates a broad substrate scope and high yields of the two types of cross-coupling reactions starting from identical starting
cobalt-catalyzed C–H bond activation of coumarins with aryl halides or pseudohalides and carbon monoxide insertion to give various 3-aroylcoumarin derivatives is described. It is the first time that CO as C1 feedstock is used as the coupling partners in cobalt-catalyzed regioselective coumarin C–H functionalization reactions. Upon activation with manganese powder, the Co catalyzes the C–H bond activation
Condensation of α-Aroylketene Dithioacetals and 2-Hydroxyarylaldehydes Results in Facile Synthesis of a Combinatorial Library of 3-Aroylcoumarins
作者:H. Surya Prakash Rao、S. Sivakumar
DOI:10.1021/jo061372e
日期:2006.11.1
facile, convenient, efficient, and high yielding synthesis of a combinatoriallibrary of 3-aroylcoumarins has been developed by the condensation of easily available α-aroylketene dithioacetals (AKDTAs) and 2-hydroxybenzaldehydes (salicylaldehydes)/2-hydroxy-1-naphthaldehyde in the presence of catalytic amount of piperidine in THF reflux. The condensation of ferrocene derived α-aroylketene dithioacetal