526-47-6Relevant academic research and scientific papers
Synthesis of indoles through acceptorless dehydrogenative coupling catalyzed by nickel on silica-alumina
Charvieux, Aubin,Hammoud, Abdul Aziz,Duclos, Marie-Christine,Duguet, Nicolas,Métay, Estelle
supporting information, (2021/07/25)
The high atom-economical formation of indoles from anilines and diols was described with affordable and easy to handle Ni/SiO2-Al2O3. After optimization, 2,3-dimethylindole was isolated with an excellent 98% yield in neat conditions. The scope of the reaction was studied and 13 indoles were isolated in 16–80% yields.
Palladium-catalyzed dearomative allylation of indoles with cyclopropyl acetylenes: access to indolenine derivatives
Lu, Chuan-Jun,Chen, Yu-Ting,Wang, Hong,Li, Yu-Jin
, p. 635 - 644 (2021/02/06)
A palladium-catalyzed redox-neutral allylic alkylation of indoles with cyclopropyl acetylenes has been disclosed. Various 1,3-diene indolenine framework bearing a quaternary stereocenter at the C3 position were synthesized straightforwardly in good to excellent yields with high regio- and stereoselectivities. The reaction could be further expanded to the dearomatization of naphthols to synthesize functionalized cyclohexadienones with 1,3-diene motifs. The reaction exhibited high atom economy and good functional group tolerance.
Allylic and Allenylic Dearomatization of Indoles Promoted by Graphene Oxide by Covalent Grafting Activation Mode
Lombardi, Lorenzo,Bellini, Daniele,Bottoni, Andrea,Calvaresi, Matteo,Monari, Magda,Kovtun, Alessandro,Palermo, Vincenzo,Melucci, Manuela,Bandini, Marco
, p. 10427 - 10432 (2020/07/24)
The site-selective allylative and allenylative dearomatization of indoles with alcohols was performed under carbocatalytic regime in the presence of graphene oxide (GO, 10 wt percent loading) as the promoter. Metal-free conditions, absence of stoichiometric additive, environmentally friendly conditions (H2O/CH3CN, 55 °C, 6 h), broad substrate scope (33 examples, yield up to 92 percent) and excellent site- and stereoselectivity characterize the present methodology. Moreover, a covalent activation model exerted by GO functionalities was corroborated by spectroscopic, experimental and computational evidences. Recovering and regeneration of the GO catalyst through simple acidic treatment was also documented.
Fe-Catalyzed Sequential C(sp3)-H/N-H Annulation of 2-Methylindoles with Ethyl Trifluoropyruvate at Room Temperature: Construction of Pyrrolo[1,2-α]indoles
Wang, Le,Wang, Le,Zhou, Jia,Chen, Han-Qia,Li, Dong-Li,Lin, Jun-Bing,Lin, Jun-Bing,Li, Ke,Ding, Tong-Mei,Zhang, Shu-Yu,Zhang, Shu-Yu
supporting information, p. 4716 - 4720 (2020/06/29)
An efficient and benign iron-catalyzed room-temperature method was developed for direct sequential C(sp3)-H/N-H annulation to construct pyrroloindole scaffolds. This strategy features cheap and readily available raw materials and mild room-temperature reaction conditions and provides a green and practical method for the one-pot rapid synthesis of a wide range of diversely functionalized pyrrolo[1,2-α]indoles.
B(C6F5)3-Catalyzed Direct C3 Alkylation of Indoles and Oxindoles
Basak, Shyam,Alvarez-Montoya, Ana,Winfrey, Laura,Melen, Rebecca L.,Morrill, Louis C.,Pulis, Alexander P.
, p. 4835 - 4840 (2020/04/22)
The direct C3 alkylation of indoles and oxindoles is a challenging transformation, and only a few direct methods exist. Utilizing the underexplored ability of triaryl boranes to mediate the heterolytic cleavage of α-nitrogen C-H bonds in amines, we have developed a catalytic approach for the direct C3 alkylation of a wide range of indoles and oxindoles using amine-based alkylating agents. We also employed this borane-catalyzed strategy in an alkylation-ring opening cascade.
Palladium-Catalyzed Amination/Dearomatization Reaction of Indoles and Benzofurans
Zhang, Zhe,Zhang, Bo-Sheng,Li, Kai-Li,An, Yang,Liu, Ce,Gou, Xue-Ya,Liang, Yong-Min
, p. 7817 - 7839 (2020/07/16)
This report describes a palladium-catalyzed dearomatization and amination tandem reaction of 2,3-disubstituted indoles and benzofurans via the Catellani strategy. This reaction provides a new method for the construction of amino-substituted indoline-fused cyclic and benzofuran spiro compounds in good yields. The reaction has broad functional group compatibility and substrate scope.
Palladium-Catalyzed Dearomative Allylic Alkylation of Indoles with Alkynes to Synthesize Indolenines with C3-Quarternary Centers
Gao, Shang,Wu, Zijun,Fang, Xinxin,Lin, Aijun,Yao, Hequan
supporting information, p. 3906 - 3909 (2016/08/16)
A palladium-catalyzed dearomative allylic alkylation of indoles with alkynes to construct indolenines with C3-quarternary centers was reported. The in situ formed arylallene intermediate omitted the need to install leaving groups on the allylic compounds and employ extra oxidants to oxidize the allylic C-H bonds. The reaction exhibited good functional group tolerance and high atom economy. Moreover, the reaction was further expanded to synthesize pyrroloindolines and furanoindolines.
Facile construction of pyrrolophenanthridone skeleton via a one-pot intramolecular Heck reaction and oxidation
Cong, Wei,Zhao, Lei,Wu, Xiaoming,Xu, Jinyi,Yao, Hequan
supporting information, p. 312 - 317 (2014/01/06)
Construction of pyrrolophenanthridone skeleton via a one-pot Pd-catalyzed intramolecular Heck reaction followed by oxidation has been achieved in moderate to good yields. The reaction mechanism has been proposed.
Reactivity of tetrahydrochromeno[2,3-b]indoles: Chromic indicators of cyanide
Douglas, Nicholas,Neef, Charles J.,Rogers, Robert A.,Stanley, Jake A.,Armitage, Jacob,Martin, Ben,Hudnall, Todd W.,Brittain, William J.
, p. 688 - 695 (2013/08/23)
The synthesis and reactivity of a tetrahydrochromeno[2,3-b]indoles are reported. Evidence for reversible ring-opening is based on H/D exchange and trapping experiments. These compounds readily undergo reaction with tetra-n-butylammonium cyanide. The cyanide reaction is 10-100× faster when the solution is irradiated with 350 nm light. Reaction with trimethylsilyl cyanide occurs only with UV irradiation demonstrating photoreactivity. The rate of tetrahydrochromeno[2,3-b]indole ring-opening is greater for (i) Me substitution at the hemiaminal carbon (compared to Ph), and (ii) substitution of fluorine at the 9-position of the indole. Under acidic conditions, the ring-opened indolium ion is observed. Copyright
Oxidative palladium(II)-catalyzed dehydrogenative C-H/C-H cross-coupling of 2,3-substituted indolines with arenes at the C7 position
Jiao, Lin-Yu,Oestreich, Martin
supporting information, p. 10845 - 10848 (2013/09/02)
Directed directing group: The C7 position of the indoline nucleus is difficult to address in C-H activation. An oxidative palladium(II) catalysis that allows for cross-dehydrogenative coupling in that position with activation of the C-H bond of the arene component is disclosed here. This C-H/C-H cross-coupling is applicable to various indolines acetylated at the nitrogen atom. Substitution at C2 is crucial for the C-H activation to occur at C7 (see scheme).
