Formation of Enehydrazine Intermediates through Coupling of Phenylhydrazines with Vinyl Halides: Entry into the Fischer Indole Synthesis
作者:Fuxu Zhan、Guangxin Liang
DOI:10.1002/anie.201207173
日期:2013.1.21
Cut to the chase: Direct formation of an enehydrazine, an intermediate in the classic Fischerindolesynthesis, solves the regioselectivity problem associated with indolization. This approach not only achieves selective synthesis of indoles through proper selection of the vinyl halide, but also leads to quick construction of desoxyeseroline and esermethole, as well as the key structural motif in the
to the myriad methods for the construction of C–N bonds, chemistry for N–N coupling, especially in an intermolecular fashion, remains underdeveloped. Here, we report a nitrene-mediated intermolecular N–N coupling of dioxazolones and arylamines under iridium or iron catalysis. These reactions offer a simple and efficient method for the synthesis of various hydrazides from readily available carboxylic
N-N 键存在于许多天然化合物中,并赋予迷人的结构和功能特性。与构建 C-N 键的无数方法相比,N-N 偶联化学,尤其是分子间偶联化学,仍然不发达。在这里,我们报告了在铱或铁催化下氮烯介导的二恶唑酮和芳胺的分子间 N-N 偶联。这些反应为从容易获得的羧酸和胺前体合成各种酰肼提供了一种简单有效的方法。尽管 Ir 催化条件通常比 Fe 催化条件具有更高的 N-N 偶联产率,但在 Fe 催化条件下,来自 α-取代羧酸的空间要求更高的二恶唑酮的反应效果要好得多。
Rh(III)-Catalyzed Oxidative Coupling of 1,2-Disubstituted Arylhydrazines and Olefins: A New Strategy for 2,3-Dihydro-1<i>H</i>-Indazoles
作者:Sangil Han、Youngmi Shin、Satyasheel Sharma、Neeraj Kumar Mishra、Jihye Park、Mirim Kim、Minyoung Kim、Jinbong Jang、In Su Kim
DOI:10.1021/ol500865j
日期:2014.5.2
A rhodium(III)-catalyzed oxidative olefination of 1,2-disubstituted arylhydrazines with alkenes via sp(2) C-H bond activation followed by an intramolecular aza-Michael reaction is described. This strategy allows the direct and efficient construction of highly substituted 2,3-dihydro-1H-indazole scaffolds.