Copper(II) Bromide/Boron Trifluoride Etherate-Cocatalyzed Cyclization of Ketene Dithioacetals and p-Quinones: a Mild and General Approach to Polyfunctionalized Benzofurans
作者:Yingjie Liu、Mang Wang、Hongjuan Yuan、Qun Liu
DOI:10.1002/adsc.200900809
日期:2010.3.22
general method for catalytic synthesis of polyfunctionalized benzofurans with the advantages of readily available starting materials, cheap catalysts, mild reaction conditions, good yields and wide range of synthetic potential for the benzofuran products. Further transformations of the resulting benzofurans to 2‐aminobenzofurans and benzofuro[2,3‐d]pyrimidine derivatives are also investigated.
开发了溴化铜(II)活化的烯酮二硫缩醛作为亲核试剂在有机化学中的新应用。在室温下在溴化铜(II)(2.0 mol%)和三氟化硼醚化物(10 mol%)的共催化下,α-吸电子基团取代的乙烯酮二硫缩醛与对苯醌在乙腈中的共轭加成和顺序环化产生了各种苯并呋喃。正式的[3 + 2]环加成反应为多官能化苯并呋喃的催化合成提供了一种通用方法,其优点是原料易得,催化剂便宜,反应条件温和,收率好,苯并呋喃产物的合成潜力大。所得苯并呋喃进一步转化为2-氨基苯并呋喃和苯并呋喃[2,3-还研究了d ]嘧啶衍生物。