开发了一种无过渡金属碱催化的 2-炔基酚分子内环化,用于简便合成 2-取代的苯并[ b ]呋喃。使用容易获得的 Cs 2 CO 3作为催化剂,在温和的反应条件下,可以以良好至优异的收率获得各种 2-芳基和 2-烷基取代的苯并[ b ]呋喃。广泛的底物范围和克级高效效率的典型维持使该协议成为合成 2-取代苯并[ b ]呋喃衍生物的潜在实用方法。
The first example of sole direct C–H bond arylation of benzo[b]furans with aryl chlorides was achieved catalyzed by a well-defined NHC-Pd(II)-Im complex. Under the suitable conditions, all reactions involving kinds of benzo[b]furans and (hetero)aryl chlorides proceeded well to give the desired C2-arylated benzo[b]furans in sole regioselectivity in acceptable to high yields, providing an efficient and
明确定义的NHC-Pd(II)-Im络合物催化了苯并[ b ]呋喃与芳基氯的唯一直接C-H键芳基化反应。在合适的条件下,所有涉及各种苯并[ b ]呋喃和(杂)芳基氯化物的反应均能顺利进行,从而以唯一的区域选择性提供所需的C2-芳基化苯并[ b ]呋喃,并以高收率接受,从而提供了有效而经济的途径用于苯并[ b ]呋喃的直接C2-H键芳基化。
Simple, Convenient, and Efficient Synthesis of 2-Aryl-substituted Benzo[b]furans
作者:Yong Jiang、Botao Gao、Wenjuan Huang、Yongmin Liang、Guosheng Huang、Yongxiang Ma
DOI:10.1080/00397910701860323
日期:2008.12.31
convenient, and efficient one-pot method for the preparation of benzofuran is reported. Sonogashira coupling reaction of aryl iodides with 2-methyl-3-butyn-2-ol was used as an acetylene source in the presence of Pd(PPh3)2Cl2 and CuI. Deprotection of the acetylene moiety in the same pot using a strong base and the second Sonogashira coupling/cyclization of and substituted o-iodophenols led to the formation
Microwave-assisted efficient synthesis of 2-arylbenzo[b]furans and 2-ferrocenylbenzo[b]furans from readily prepared propargylic alcohols and o-iodophenols
one-pot with iodobenzene, 2-methyl-3-butyn-2-ol and 2-iodo-4-methylphenol as reactants. A simple and efficient method for synthesis of 2-arylbenzo[b]furnas and 2-ferrocenylbenzo[b]furans has been developed from the Sonogashira coupling/cyclization reaction of propargylic alcohols and o-iodophenols in the presence of silica gel and catalytic amounts of PdCl2(PPh3)2 (2 mol%) and CuI (2 mol%) under microwave