期刊
JOURNAL OF ORGANIC CHEMISTRY
卷 81, 期 19, 页码 9381-9388出版社
AMER CHEMICAL SOC
DOI: 10.1021/acs.joc.6b02092
关键词
-
资金
- National Natural Science Foundation of China [21473100, 21403123]
- Shandong Province Higher Educational Science and Technology Program [J14LC17]
- Opening Foundation of Shandong Provincial Key Laboratory of Detection Technology for Tumor Makers [KLDTTM2015-9]
- Doctoral Start-Up Scientific Research Foundation of Qufu Normal University [BSQD2012018]
Gold-catalyzed cyclization of 2-alkynyl-N-propargylanilines provides a step-economic method for the construction of three-dimensional indolines. In this article, the M06 functional of density functional theory was employed to gain deeper insights into the reaction mechanism and the associated intriguing experimental observations. The reaction was found to first undergo Au(I)-induced cyclization to form an indole intermediate, 1,3-propargyl migration, and substitution with the substrate 2-alkynyl-N-propargylaniline (R1) to generate the intermediate product P1, an allene species. Subsequently, Au(I)-catalyzed conversion of P1 into the final product P2, an indoline compound, occurs first through direct cyclization rather than via the previously proposed four-membered carbocycle intermediate. Thereafter, water-assisted oxygen heterocycle formation and proton transfer generate the final product. The calculated activation free energies indicate that P1 formation is 5.9 times slower than P2 formation, in accordance with the fact that P1 formation is rate-limiting. Futhermore, the intriguing experimental phenomenon that P2 can be accessed only after almost all the substrate R1 converts to P1 although P1 formation is rate-limiting was rationalized by employing an energetic span model. We found the initial facile cyclization to form a highly stable indole intermediate in the formation of P1 is the key to the intriguing experimental phenomenon.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据