Cp*Co(<scp>iii</scp>)-Catalyzed oxidative [5+2] annulation: regioselective synthesis of 2-aminobenzoxepines <i>via</i> C–H/O–H functionalization of 2-vinylphenols with ynamides
作者:Xiang-Lei Han、Xu-Ge Liu、E Lin、Yunyun Chen、Zhuangzhong Chen、Honggen Wang、Qingjiang Li
DOI:10.1039/c8cc06807k
日期:——
A Cp*Co(III)-catalyzed [5+2] C–H annulation reaction of 2-vinylphenols with ynamides was developed. The reaction led to the efficient synthesis of valuable 2-aminobenzoxepines in high regioselectivity. Mild reaction conditions, good functional group tolerance, and moderate to good yields were observed. The synthetic utility was demonstrated by a gram-scale synthesis and further transformations of the
Electrooxidative Rhodium‐Catalyzed [5+2] Annulations via C−H/O−H Activations
作者:Yulei Wang、João C. A. Oliveira、Zhipeng Lin、Lutz Ackermann
DOI:10.1002/anie.202016895
日期:2021.3.15
five‐ and six‐membered heterocycles. In contrast, we herein describe the first electrochemical metal‐catalyzed [5+2] cycloadditions to assemble valuable seven‐membered benzoxepine skeletons by C−H/O−H activation. The efficient alkyne annulation featured ample substrate scope, using electricity as the only oxidant. Mechanistic studies provided strong support for a rhodium(III/I) regime, involving a
Straightforward Assembly of Benzoxepines by Means of a Rhodium(III)-Catalyzed C–H Functionalization of <i>o</i>-Vinylphenols
作者:Andrés Seoane、Noelia Casanova、Noelia Quiñones、José L. Mascareñas、Moisés Gulías
DOI:10.1021/ja410538w
日期:2014.1.22
Readily available o-vinylphenols undergo a formal (5 + 2) cycloaddition to alkynes when treated with catalytic amounts of [Cp*RhCl2](2) and Cu(OAc)(2). The reaction, which involves the cleavage of the terminal C-H bond of the alkenyl moiety, generates highly valuable benzoxepine skeletons in a practical, versatile, and atom-economical manner. Using carbon monoxide instead of an alkyne as reaction partner leads to coumarin products which formally result from a (5 + 1) cycloaddition.
Bismuth(III)-Catalyzed 1,8-Addition/Cyclization/Rearrangement of Propargylic <i>para</i>-Quinone Methides with 2-Vinylphenol: Synthesis of Indeno[2,1-<i>c</i>]chromenes
The unique reactivity of in situ generated propargylic para-quinone methides as a new type of five-carbon synthon has been discovered by a novel bismuth(III)-catalyzed tandem annulation reaction. This 1,8-addition/cyclization/rearrangement cyclization cascade reaction is characterized by unusual structural reconstruction of 2-vinylphenol, involving cleavage of the C1′═C2′ bond and formation of four new