52604-16-7Relevant articles and documents
Nickel-catalyzed C3-alkylation of indoles with alcohols: Via a borrowing hydrogen strategy
Hu, Miao,Jiang, Yong,Sun, Nan,Hu, Baoxiang,Shen, Zhenlu,Hu, Xinquan,Jin, Liqun
, p. 10057 - 10062 (2021/06/15)
An efficient method for the Ni-catalyzed C3-alkylation of indoles using readily available alcohols as the alkylating reagents has been developed. The alkylation was addressed with an air and moisture-stable binuclear nickel complex ligated by tetrahydroquinolin-8-one as the effective pre-catalyst. The newly developed transformation could accommodate a broad substrate scope including primary/secondary benzylic and aliphatic alcohols and substituted indoles. Mechanistic studies suggested that the reaction proceeds through a borrowing hydrogen pathway.
Et3SiH + KO: T Bu provide multiple reactive intermediates that compete in the reactions and rearrangements of benzylnitriles and indolenines
Arokianathar, Jude N.,Clark, Kenneth F.,Dimitrova, Daniela,Leach, Stuart G.,Murphy, John A.,Poole, Darren L.,Smith, Andrew J.
, p. 12364 - 12370 (2020/12/08)
The combination of potassium tert-butoxide and triethylsilane is unusual because it generates multiple different types of reactive intermediates simultaneously that provide access to (i) silyl radical reactions, (ii) hydrogen atom transfer reactions to cl
Divergent Syntheses of Indoles and Quinolines Involving N1-C2-C3 Bond Formation through Two Distinct Pd Catalyses
San Jang, Su,Kim, Young Ho,Youn, So Won
supporting information, p. 9151 - 9157 (2020/11/03)
Pd-catalyzed annulative couplings of 2-alkenylanilines with aldehydes using alcohols as both the solvent and hydrogen source have been developed. These domino processes allow divergent syntheses of two significant N-heterocycles, indoles and quinolines, from the same substrate by tuning reaction parameters, which seems to invoke two distinct mechanisms. The nature of the ligand and alcoholic solvent had a profound influence on the selectivity and efficiency of these protocols. Particularly noteworthy is that indole formation was achieved by overcoming two significant challenges, regioselective hydropalladation of alkenes and subsequent reactions between the resulting Csp3-Pd species and less reactive imines.
Iron-Catalyzed Direct C3-Benzylation of Indoles with Benzyl Alcohols through Borrowing Hydrogen
Di Gregorio, Giovanni,Mari, Michele,Bartoccini, Francesca,Piersanti, Giovanni
, p. 8769 - 8775 (2017/08/23)
We present the coupling of primary and secondary benzyl alcohols with indoles to form 3-benzylated indoles and H2O that is catalyzed, for the first time, by a complex of earth-abundant iron. This transformation accommodates a variety of substrates and is distinguished by its operational simplicity, sustainability, high functional-group tolerance, and amenability to gram-scale synthesis. On the basis of the preliminary experimental observations, we propose that the reaction proceeds through a borrowing hydrogen process.
A kind of high-efficient synthetic indole and isoquinoline derivatives (by machine translation)
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Paragraph 0059; 0060, (2016/10/07)
The invention discloses a substituted indole and isoquinoline preparation method, which belongs to the technical field of organic chemical synthesis. This method adopts the oxygen as the oxidizing agent, various substituents substituted alkyne starting material of the aromatic amine or [...] , by transition metal-catalyzed, get containing indole or isoquinoline compound of the structure. The reaction raw material, oxidizing agent and cheap and easily obtained catalyst, synthesis technique is simple, which greatly reduces the cost of synthesizing; mild reaction conditions, high yield, easy industrialization; reaction raw materials and catalyst cleaning non-toxic, small pollution to the environment. Such compounds and their derivatives as an important fine chemicals, in the medical, agricultural chemicals, perfume and widely used photoelectric and other industries. (by machine translation)
Rh-Catalyzed oxidative C-H activation/annulation: Converting anilines to indoles using molecular oxygen as the sole oxidant
Zhang, Guoying,Yu, Hui,Qin, Guiping,Huang, Hanmin
supporting information, p. 4331 - 4334 (2014/04/17)
A practical and efficient Rh(iii)-catalyzed aerobic C-H activation has been developed for the facile synthesis of a broad range of indoles from simple anilines and alkynes. The protocol could be conducted under mild conditions and used environmentally friendly oxygen as the sole clear oxidant.
An efficient route to 2,3-disubstituted indoles via reductive alkylation using H2 as reductant
Cao, Liang-Liang,Wang, Duo-Sheng,Jiang, Guo-Fang,Zhou, Yong-Gui
supporting information; experimental part, p. 2837 - 2839 (2011/06/21)
An efficient route to 2,3-disubstituted indoles was developed via reductive alkylation of 2-substituted indoles using hydrogen as a clean and atom economic reductant under ambient pressure.
The palladium-catalyzed reaction of o-alkynyltrifluoroacetanilides with alkyl halides. An entry into 2-substituted 3-alkylindoles
Arcadi, Antonio,Cacchi, Sandro,Fabrizi, Giancarlo,Marinelli, Fabio
, p. 394 - 396 (2007/10/03)
Indolylcarboxylate esters 2 and 2-substituted-3-benzylindoles 4 are prepared usually in good yield through the palladium-catalyzed reaction of o- alkynyltrifluoro acetanilides with ethyl iodoacetate or benzyl bromide. Best results are obtained by employing Pd2(dba)3 and tris(2,4,6- trimethoxyphenyl)phosphine in THF.
Reactions of unsaturated azides, 12[≠] azido-1,2,3-triphenylpropenes of varying stabilities: A corrigendum of structure assignment
Banert, Klaus,Hagedorn, Manfred,Liedtke, Christine,Melzer, Antje,Schoeffler, Claudia
, p. 257 - 267 (2007/10/03)
A reinvestigation of the reaction between 2,3-diphenyl-2-H-azirine (1) and phenyldiazomethane (2) has shown that a literature report has to be corrected since no vinyl azide 4 but rather the allylic compound 3-azido- 1,2,3-triphenyl-1-propene (3) is produced. This stable substance, which can also be prepared by substitution reactions of allylic bromide (E)-10 or from alcohol (E)-11, may be separated into its geometrical isomers (E)-3 and (Z)- 3, although these equilibrate through rapid [3,3] sigmatropic migration of the azido group. Attempts to synthesize 4 by dehydration of azido alcohols 7 using methanesulfonyl chloride and sulfur dioxide or by elimination of hydrogen chloride from azides 15 led only to 3 and 2-benzyl-2,3-diphenyl-2H- azirine (14). This heterocycle, which can also be prepared by Neber rearrangement, has been found to be the thermal and photochemical decomposition product of the unstable vinyl azides 4. However, dehydrations of 7 using thionyl chloride at low temperature have led to the first isolation of 1-azido-1,2,3-triphenyl-1-propenes (4). Starting with 3 and various other allylic azides, rearrangement reactions involving sigmatropic shift of the azido group or photochemical cis-trans isomerization have been investigated, as have base-catalyzed (prototropic) rearrangements to give vinyl azides.
"Site Selective" Formation of Low-Valent Titanium Reagents: An "Instant" Procedure for the Reductive Coupling of Oxo Amides to Indoles
Fuerstner, Alois,Hupperts, Achim,Ptock, Arne,Janssen, Edo
, p. 5215 - 5229 (2007/10/02)
Aromatic acylamido carbonyl compounds are readily cyclized to indole derivatives upon treatment with low-valent titanium reagents of the formal oxidation states 0, +1, and +2.Other strong reducing agents such as SmI2 and low-valent zirconium, niobium, and tungsten complexes are also capable of effecting such intramolecular alkylidenation reactions of amides.From the preparative point of view these heterocycle syntheses are best effected with an active titanium species which is prepared in the presence of the carbonyl compound upon coordination of TiCln (n = 3, 4) to the oxo amide substrate and reduction of this complex with zinc dust ("instant" method).This procedure turned out to be as effective as the titanium-graphite-based methodology previously described but is much easier to perform as all hazardous reagents are avoided. "Instant" cyclizations can also be run in nonetheral solvents such as DMF, ethyl acetate, or acetonitrile and turned out to be compatible with many functional groups.The method was used to cyclize oxo amide 15 to (+)-aristoteline, and it applies nicely to the synthesis of strained indole derivatives, the formation of benzofurans, conventional McMurry reactions of aldehydes and ketones, and the dimerization of alkynes.Metals such as zirconium can also be activated in situ by reduction of ZrCl4 in the presence of a carbonyl compound.On the basis of the results obtained with substrates bearing appropriate structural probes a mechanism for such intramolecular keto-amide coupling processes is proposed.Carbonyl dianions, formed upon two-electron reduction of the keto group, are the most likely reactive intermediates.Electrochemical investigations support this mechanistic interpretation.
