98055-06-2Relevant academic research and scientific papers
Modular counter-Fischer?indole synthesis through radical-enolate coupling
Chung, Hyunho,Kim, Jeongyun,Gonzalez-Montiel, Gisela A.,Cheong, Paul Ha-Yeon,Lee, Hong Geun
supporting information, p. 1096 - 1102 (2021/01/26)
A single-electron transfer mediated modular indole formation reaction from a 2-iodoaniline derivative and a ketone has been developed. This transition-metal-free reaction shows a broad substrate scope and unconventional regioselectivity trends. Moreover, important functional groups for further transformation are tolerated under the reaction conditions. Density functional theory studies reveal that the reaction proceeds by metal coordination, which converts a disfavored 5-endo-trig cyclization to an accessible 7-endo-trig process.
Palladium-Catalyzed C–C Ring Closure in α-Chloromethylimines: Synthesis of 1H-Indoles
Bellezza, Delia,Noverges, Bárbara,Fasano, Francesco,Sarmiento, Jeymy T.,Medio-Simón, Mercedes,Asensio, Gregorio
, p. 1229 - 1235 (2019/01/04)
The C-C ring closure of α-chloromethyl alkyl or aryl N-aryl imines catalyzed with 1 to 10 % Pd(OAc)2/P(p-tolyl)3 afford efficiently 2-aryl- and 2-alkyl-1H-indoles. The heterocyclization reaction involves the initial formation of [2-(arylimino)ethyl]palladium(II) chloride complexes with subsequent C-H activation of the aromatic amine ring. Readily or commercially available α-chloromethyl-aryl or -alkyl ketones are used as the precursors. Functionalized indoles at the benzene ring are obtained when the imines are derived from substituted anilines.
Au-catalyzed synthesis of 2-alkylindoles from N-arylhydroxylamines and terminal alkynes
Wang, Yanzhao,Ye, Longwu,Zhang, Liming
supporting information; experimental part, p. 7815 - 7817 (2011/08/06)
The first gold-catalyzed addition of N-arylhydroxylamines to aliphatic terminal alkynes is developed to access O-alkenyl-N-arylhydroxylamines, which undergo facile in situ sequential 3,3-rearrangements and cyclodehydrations to afford 2-alkylindoles with regiospecificity and under exceptionally mild reaction conditions.
PdII-catalysed C-H functionalisation of indoles and pyrroles assisted by the removable N-(2-pyridyl)sulfonyl group: C2-alkenylation and dehydrogenative homocoupling
Garcia-Rubia, Alfonso,Urones, Beatriz,Arrayas, Ramon Gomez,Carretero, Juan Carlos
supporting information; experimental part, p. 9676 - 9685 (2010/10/18)
The easily installed and removed N-(2-pyridyl)sulfonyl group exerts complete C2 regiocontrol over the PdII-catalysed C-H alkenylation of indoles and pyrroles, affording the corresponding products in good isolated yields (typically ≥ 70%). A remarkable feature of this catalyst system is that it tolerates a wide variety of substituted alkenes, including conjugated electrondeficient alkenes, styrenes and 1,3- dienes, as well as conjugated 1,1- and 1,2-disubstituted olefins. The final reductive desulfonylation affords the C2- substituted, free-NH indoles and pyrroles in good yield. This N-(2-pyridyl)- sulfonyl-directing strategy has also been extended to the development of a protocol for the intermolecular, dehydrogenative homocoupling of indoles, providing 2,2'-biindoles. Mechanistic work based upon reactions with isotopically labelled starting materials and competitive kinetic studies of electronically varied substrates suggests a chelation- assisted electrophilic aromatic substitution palladation mechanism.
Efficient synthesis of 2-mono and 2,3-disubstituted indoles via palladium-catalyzed oxidation of aminoalcohols
Aoyagi, Yutaka,Shishikura, Masahiro,Mizusaki, Toshihiko,Komine, Takashi,Yoshinaga, Tokuji,Inaba, Haruko,Ohta, Akihiro,Takeya, Koichi
, p. 1055 - 1059 (2008/12/20)
Efficient synthesis of 2-mono- and 2,3-disubstituted indoles has been accomplished via palladium-catalyzed oxidation of aminoalcohols.
Kinetic resolutions of lndolines by a nonenzymatic acylation catalyst
Arp, Forrest O.,Fu, Gregory C.
, p. 14264 - 14265 (2008/03/13)
The first method for the kinetic resolution of indolines through catalytic N-acylation is described. To improve the selectivity factor, new planar-chiral PPY-derived catalysts were synthesized, wherein the chiral environment was systematically modified. This work provides a rare example of a nonenzyme-based acylation catalyst for the kinetic resolution of amines. Copyright
Radical cyclisation reactions with indoles
Flanagan, Stuart R.,Harrowven, David C.,Bradley, Mark
, p. 1795 - 1798 (2007/10/03)
Several radical cyclisation reactions involving indoles are described. Most notably, we have shown that radical additions to C3 of an indole are frequently facile. A dichotomy in the course of radical cyclisation reactions to C2 of the indole has also been exposed wherein 6-endo-trig cyclisations are propagated by the loss of a hydrogen atom from C2 while 5-exo-trig cyclisations are propagated by hydrogen atom abstraction at C3 from tributyltin hydride. Cyclisations involving the addition of indolyl radical intermediates to arenes have also been demonstrated.
Reactivities of Nitrenes Generated by Photolysis of 2-(ω-Phenylalkyl)phenyl Azides
Murata, Shigeru,Yoshidome, Ryuichi,Satoh, Youji,Kato, Noriyasu,Tomioka, Hideo
, p. 1428 - 1434 (2007/10/02)
In order to investigate the reactivity of a photolytically generated arylnitrene with an intramolecular CH bond, the photochemistry of 2-(ω-phenylalkyl)phenyl azides (1a-d) was examined.Irradiation of 1 in solution revealed that the insertion of the nitrene into an adjacent CH bond to give cyclic compounds 4 and 5 occurs favorably only when a reactive CH bond, such as benzylic, is located close to the nitrenic center.This process can compete with the formation of products derived from triplet nitrene, but not with the capture of didehydroazepine by DEA.On the other hand, irradiation of 1b in an Ar matrix at 12 K gave a mixture of the CH insertion product 4b and the didehydroazepine 15.The origin of the difference in reactivity of the nitrene observed in solutions and in matrix, and the spin state of the nitrene involved in the CH insertion reaction, are discussed.
