Iridium/Acid Cocatalyzed Direct Access to Fused Indoles via Transfer Hydrogenative Annulation of Quinolines and 1,2-Diketones
摘要:
Herein, we present an unprecedented iridium/acid cocatalyzed construction of fused indoles via transfer hydrogenative annulation of nonactivated quinolines and 1,2-diketones. The products are assembled via initial reduction followed by selective coupling of 1,2-diketones with the N and C8 sites of the quinolyl skeleton. The developed synthetic method features operational simplicity, readily available feedstocks, applicability for streamline synthesis of functional molecules, high step and atom efficiency, and generation of water as the byproduct.
Zirconium Hydrazinediido Complexes Derived from Cyclic Hydrazines and Their Role in the Catalytic Synthesis of 1,7-Annulated Indoles
作者:Solveig A. Scholl、Hubert Wadepohl、Lutz H. Gade
DOI:10.1021/om301235d
日期:2013.2.11
Reaction of cyclic 1,1'-disubstituted hydrazines with the bis(dimethylamido)zirconium complex [Zr(N-Xyl)(2)N-py} (NMe2)(2)] (1) in the presence of dmap yielded the hexacoordinate zirconium hydrazinediido complexes [Zr(N-Xyl)(2)N-py}(=NNC9H10)(dmap)(2)] (2) and [Zr(N-Xyl)(2)N-py} (=NNC12H8)(dmap)(2)] (3). Hydrazinediides are thought to be key intermediates in the zirconium-catalyzed reaction of cyclic 1,1'-disubstituted hydrazines and disubstituted alkynes to yield 1,7-annulated indoles. Their basic structural motif is found in 5-HT3 receptor antagonists such as Cilansetron.