Synthesis of Cycloheptatrienes, Oxepines, Thiepines, and Silepines: A Comparison between Brønsted Acid and Au‐Catalysis
Synthesis of Cycloheptatrienes, Oxepines, Thiepines, and Silepines: A Comparison between Brønsted Acid and Au‐Catalysis
复制标题
环庚三烯、Oxepines、Thiepines 和 Silepines 的合成:布伦斯台德酸和 Auâ 催化的比较
DOI:
10.1002/ejoc.202001072
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发表时间:
2020
影响因子:
2.8
通讯作者:
M. Alcarazo
中科院分区:
文献类型:
--
作者:
K. Sprenger;C. Golz;M. Alcarazo
The cyclization of 1‐(benzyl‐, oxyaryl‐, thioaryl‐, and silaaryl)‐2‐ethynylbenzenes under Brønsted acid‐ and Au(I)‐catalysis is described. Brønsted acid catalysis favors without exception the formation of the products derived from the regioselective protonation of the alkyne to generate the most stable vinyl carbocation intermediate. This determines the type of cyclization following this initial step and therefore, the structure of the products. Contrarily, with only a few exceptions, for example, when the substrate contains a terminal alkyne moiety, Au‐catalysis preferentially promotes the formation of seven‐membered rings via 7‐endo‐dig cyclization. This reaction pathway is imposed even if a priori the natural electronic polarization in the substrates would suggest another operating mechanism. Making use of these reactivity patterns, a series of structurally differentiated dibenzo‐cycloheptatrienes, ‐oxepines, ‐thiepines and ‐silepines have been synthesized with excellent yields and regioselectivities.
影响因子:
3.2
作者:
P. Wyatt;A. Hudson;J. Charmant;A. Orpen;H. Phetmung
通讯作者:
H. Phetmung
影响因子:
--
作者:
G. Mehler;P. Linowski;J. Carreras;A. Zanardi;J. W. Dube;M. Alcarazo
通讯作者:
M. Alcarazo
影响因子:
16.6
作者:
Hartung, Thierry;Machleid, Rafael;Alcarazo, Manuel
通讯作者:
Alcarazo, Manuel