Ru(III)-Catalyzed Cyclization of Arene-Alkene Substrates via Intramolecular Electrophilic Hydroarylation
摘要:
We herein report that RuCl3/AgOTf has proven to be a hydroarylation catalyst with an efficiency and scope superior to previously known methods. This catalyst demonstrated consistent performance with arene-ene substrates of diverse structural features, providing good to excellent yields of cyclization products (chromanes, tetralins, terpenoids, dihydrocoumarins).
Catalytic C−H Bond Functionalization with Palladium(II): Aerobic Oxidative Annulations of Indoles
摘要:
A palladium-catalyzed aerobic oxidative annulation of indoles is described. We have demonstrated that a variety of factors influence these cyclizations, and in particular the electronic nature of the pyridine ligand is crucial. It is also remarkable that these oxidative cyclizations can proceed in good yield despite background oxidative decomposition pathways, testament to the facile nature with which molecular oxygen can serve as the direct oxidant for Pd(0). We have also shown that the mechanism most likely involves initial indole palladation (formal C-H bond activation) followed by migratory insertion and beta-hydrogen elimination.
Enantioselective Fujiwara-Moritani Indole and Pyrrole Annulations Catalyzed by Chiral Palladium(II)-NicOx Complexes
作者:Julia A. Schiffner、Thorsten H. Wöste、Martin Oestreich
DOI:10.1002/ejoc.200901129
日期:2010.1
catalytic asymmetric Fujiwara-Moritani ring closures of several indole- and pyrrole-based cyclization precursors are reported. These unprecedented oxidative palladium(II)-catalyzed annulations allow for the formation of a stereogenic quaternary carbon atom, and decent levels of enantiocontrol are seen in 5-exo-trig cyclizations (54 % ee for an indole and 76 % ee for a pyrrole) while 6-exo-trig ring
Highly Efficient Construction of Benzene Ring in Carbazoles by Palladium-Catalyzed <i>endo</i>-Mode Oxidative Cyclization of 3-(3‘-Alkenyl)indoles
作者:Aidi Kong、Xiuling Han、Xiyan Lu
DOI:10.1021/ol060039u
日期:2006.3.1
[reaction: see text] A highly efficient construction of the benzene ring in carbazoles by palladium-catalyzed endo-mode oxidative cyclization of 3-(3'-alkenyl)indoles was developed. The reaction utilizes benzoquinone as the stoichiometric oxidant and is conducted under mild conditions.
Enantioselective synthesis of tetrahydrocyclopenta[b]indole bearing a chiral quaternary carbon center via Pd(<scp>ii</scp>)–SPRIX-catalyzed C–H activation
作者:Mohamed Ahmed Abozeid、Shiho Sairenji、Shinobu Takizawa、Makoto Fujita、Hiroaki Sasai
DOI:10.1039/c7cc03199h
日期:——
conjunction with the chiral spiro bis(isoxazoline) ligand (SPRIX). The presence of an N-allyl substituent on the substrate has a strong impact on both reactivity and selectivity, leading to tricyclic indole products (up to 96% ee) with a chiral quaternary carbon center.
A Catalytic Asymmetric Fujiwara-Moritani
Cyclization
作者:Martin Oestreich、Julia Schiffner、Axel Machotta
DOI:10.1055/s-2008-1078271
日期:——
An enantioselective intramolecular Fujiwara-Moritani reaction involving direct C-H functionalization using modified PyOX ligands is reported for the first time. Screening of several ligand-oxidant combinations eventually produced a stereogenic quaternary carbon with promising enantiocontrol (54% ee) and in good chemical yield (71%).
C–H bond functionalizations with palladium(II): intramolecular oxidative annulations of arenes
作者:Eric M. Ferreira、Haiming Zhang、Brian M. Stoltz
DOI:10.1016/j.tet.2008.01.052
日期:2008.6
Oxidative annulations for the synthesis of carbocycles were developed using a catalytic palladium(II) system. Indoles with pendant olefin tethers were oxidativelycyclized to form annulated products. Electron-rich aromatic systems were also investigated, culminating in the synthesis of benzofurans and dihydrobenzofurans by a similar protocol. These reactions were demonstrated to proceed by an initial
使用催化钯 (II) 系统开发了用于合成碳环的氧化环。具有侧链烯烃系链的吲哚被氧化环化以形成环状产物。还研究了富含电子的芳香系统,最终通过类似的协议合成苯并呋喃和二氢苯并呋喃。这些反应被证明是通过初始 CH 键官能化事件进行的,然后是烯烃插入和 β-氢化物消除。