Lewis Acid-Catalyzed [4 + 2] Benzannulation between Enynal Units and Enols or Enol Ethers: Novel Synthetic Tools for Polysubstituted Aromatic Compounds Including Indole and Benzofuran Derivatives
作者:Naoki Asao、Haruo Aikawa
DOI:10.1021/jo060597m
日期:2006.7.1
enynals 1, including o-(alkynyl)benzaldehydes, and carbonyl compounds 2, such as aldehydes and ketones, in the presence of a catalytic amount of AuBr3 in 1,4-dioxane at 100 °C gave the functionalized aromatic compounds 3 in high yields. Similarly, the AuBr3-catalyzed reactions of 1 with acetal compounds 5 afforded the corresponding aromatic compounds 3 in good yields. On the other hand, when the reaction
在1,4-二恶烷中催化量的AuBr 3存在下,烯醇1(包括邻-(炔基)苯甲醛)和羰基化合物2(例如醛和酮)在100°C下反应,得到官能化的芳族化合物3高产。类似地,1与乙缩醛化合物5的AuBr 3催化反应以良好的产率提供了相应的芳族化合物3。另一方面,当反应在催化量的Cu(NTf 2)2和1当量的H 2 O在(CH 2Cl)2在100℃下,在3 ℃以上选择性地获得脱羰基萘产物4。苯并杂杂芳族化合物,例如吲哚衍生物13和苯并呋喃衍生物15,也通过使用本发明的苯环化方法合成。