1859-39-8Relevant academic research and scientific papers
A General Synthesis of N-Hydroxyindoles
Wong, Audrey,Kuethe, Jeffrey T.,Davies, Ian W.
, p. 9865 - 9866 (2003)
A general method for the formation of N-hydroxyindoles is demonstrated through a lead-promoted intramolecular reductive cyclization of o-nitrobenzyl ketones and aldehydes under transfer hydrogenation conditions. The N-hydroxyindoles are isolated in high purity and excellent yield (> 90%) in an operationally simple procedure. This new method is exemplified by a two-step synthesis of the naturally occurring 1-methoxyindole-3-carboxaldehyde, which is pivotal in many alkaloid total syntheses.
Counterion Control of t-BuO-Mediated Single Electron Transfer to Nitrostilbenes to Construct N-Hydroxyindoles or Oxindoles
Driver, Tom G.,Sung, Siyoung,Wink, Donald J.,Zadrozny, Joseph M.,Zhao, Yingwei,Zhu, Haoran
, p. 19207 - 19213 (2021/08/09)
tert-Butoxide unlocks new reactivity patterns embedded in nitroarenes. Exposure of nitrostilbenes to sodium tert-butoxide was found to produce N-hydroxyindoles at room temperature without an additive. Changing the counterion to potassium changed the reaction outcome to yield solely oxindoles through an unprecedented dioxygen-transfer reaction followed by a 1,2-phenyl migration. Mechanistic experiments established that these reactions proceed via radical intermediates and suggest that counterion coordination controls whether an oxindole or N-hydroxyindole product is formed.
Iron-Catalyzed Reductive Cyclization of o-Nitrostyrenes Using Phenylsilane as the Terminal Reductant
Shevlin, Michael,Guan, Xinyu,Driver, Tom G.
, p. 5518 - 5522 (2017/08/17)
Using microscale high-throughput experimentation, an efficient, earth-abundant iron phenanthroline complex was discovered to catalyze the reductive cyclization of ortho-nitrostyrenes into indoles via nitrosoarene reactive intermediates. This method requires only 1 mol % of Fe(OAc)2 and 1 mol % of 4,7-(MeO)2phen and uses phenylsilane as a convenient terminal reductant. The scope and limitations of the method were illustrated with 21 examples, and an investigation into the kinetics of the reaction revealed first-order behavior in catalyst and silane and zero-order behavior with respect to nitrostyrene.
Reductive cyclizations of nitroarenes to hydroxamic acids by visible light photoredox catalysis
Cismesia, Megan A.,Ischay, Michael A.,Yoon, Tehshik P.
, p. 2699 - 2705 (2013/10/21)
We have developed a photocatalytic reduction of nitroarenes as an efficient, chemoselective route to biologically important N-phenyl hydroxamic acid scaffolds. Optimal conditions call for 2.5 mol% of a ruthenium photocatalyst, visible light irradiation, and a dihydropyridine terminal reductant. Because of the mild nature of the visible light activation, functional groups that might be sensitive to other non-photochemical reduction methods are easily tolerated. Georg Thieme Verlag Stuttgart New York.
