Gold(I)-Catalyzed Tandem Reactions Initiated by Hydroamination of Alkynyl Carbamates: Application to the Synthesis of Nitidine
作者:Taro Enomoto、Anne-Lise Girard、Yoshizumi Yasui、Yoshiji Takemoto
DOI:10.1021/jo901906b
日期:2009.12.4
convenient and direct synthesis of 1,2-dihydroisoquinolines, the gold(I)-catalyzed intramolecular hydroamination of (2-alkynyl)benzyl carbamates has been developed. The reaction with cationic gold(I) complex [AuCl(PPh3)/AgNTf2] proceeded at room temperature, giving the desired 6-endo adducts. The addition of alcohol efficiently promoted the reaction, and the amount of the catalyst could be reduced to
为了方便,直接地合成1,2-二氢异喹啉,已经开发了金(I)催化的(2-炔基)苄基氨基甲酸酯的分子内氢化胺化反应。与阳离子金(I)配合物[AuCl(PPh 3)/ AgNTf 2 ]的反应在室温下进行,得到所需的6-内加合物。醇的添加有效地促进了反应,并且催化剂的量可以减少至1mol%。然而,带有缺电子的芳基或烷基的炔烃主要产生5- exo加合物。在这种情况下,请使用大块金催化剂AuCl [(o -biPh)(t Bu)2 P] Cl / AgNTf 2改善了区域选择性,使6-内酰胺加合物具有更好的收率。此外,带有乙缩醛或烯酮的氨基甲酸炔基酯的加氢胺化反应已成功地通过单一催化剂介导的串联环化反应(包括缩合反应或迈克尔加成所得的氨基甲酸酯)进行了简明的四环杂环(如亚硝胺)的合成。