3771-60-6Relevant academic research and scientific papers
Transition-Metal-Free C3 Arylation of Indoles with Aryl Halides
Chen, Ji,Wu, Jimmy
supporting information, p. 3951 - 3955 (2017/03/27)
We report an unprecedented transition metal-free coupling of indoles with aryl halides. The reaction is promoted by KOtBu and is regioselective for C3 over N. The use of degassed solvents devoid of oxygen is necessary for the success of the transformation. Preliminary studies implicate a hybrid mechanism that involves both aryne intermediates and non-propagative radical processes. Electron transfer is also a distinct possibility. These conclusions were substantiated by EPR data, isotopic labeling studies, and the use of radical scavengers and electron transfer inhibitors.
Dearomatization Strategy for the Synthesis of Arylated 2H-Pyrroles and 2,3,5-Trisubstituted 1H-Pyrroles
Polák, Peter,Tobrman, Tomá?
, p. 4608 - 4611 (2017/09/12)
The first high-yielding route to arylated 2H-pyrroles was developed. The methodology utilizes 2,5-disubstituted pyrroles that are metalated, and the aryl substituents are introduced by a palladium-catalyzed cross-coupling reaction. The prepared pyrroles can be rearranged to 2,3,5-trisubstituted pyrroles under acidic conditions. Attempts to convert the 2,3,5-trisubstituted pyrroles to 2,3,4,5-tetrasubstituted pyrroles by the dearomatization rearrangement strategy were unsuccessful.
A short synthesis of 2,3,5-Trisubstituted pyrroles by an alkylation/dehydrocyanation sequence
Kucukdisli, Murat,Nebe, Marco M.,Bartelt, Solveig M.,Opatz, Till
, p. 378 - 390 (2017/03/14)
2,3,5-Trisubstituted pyrroles were prepared in a one-pot procedure from readily available 3,5-disubstituted 3,4-dihydro-2H-pyrrole-2-carbonitriles by an alkylation/dehydrocyanation sequence. The method was also applied to α,ω-dihaloalkanes to furnish dipyrroles tethered with an alkyl spacer.
Highly regio-and enantioselective synthesis of polysubstituted 2 H -pyrroles via pd-catalyzed intermolecular asymmetric allylic dearomatization of pyrroles
Zhuo, Chun-Xiang,Zhou, Yong,You, Shu-Li
supporting information, p. 6590 - 6593 (2014/05/20)
A highly efficient synthesis of chiral polysubstituted 2H-pyrrole derivatives via a Pd-catalyzed intermolecular asymmetric allylic dearomatization reaction of pyrroles is presented. With the commercially available palladium precursor and chiral ligand, the polysubstituted 2H-pyrrole products containing a chiral quaternary carbon center were obtained with up to 97% ee and >95/5 regioselectivity.
Palladium-catalyzed C-H arylation of 2,5-substituted pyrroles
Wagner, Anna M.,Sanford, Melanie S.
supporting information; experimental part, p. 288 - 291 (2011/04/17)
The palladium-catalyzed direct arylation of 2,5-substituted pyrrole derivatives with diaryliodonium salts to generate tri-, tetra-, and penta-substituted pyrrole products is described. The scope and limitations of these transformations are also reported.
Nitrogen fixation: Synthesis of heterocycles using molecular nitrogen as a nitrogen source
Mori, Miwako,Akashi, Masaya,Hori, Masanori,Hori, Katsutoshi,Nishida, Mayumi,Sato, Yoshihiro
, p. 1655 - 1670 (2007/10/03)
Nitrogen fixation using transition metals is a fascinating process. We have already reported on the incorporation of molecular nitrogen into organic compounds using a titanium-nitrogen complex reported by Yamamoto. We developed a novel titanium-catalyzed nitrogenation procedure using TiCl4 in the presence of an excess amount of Li and TMSCl. In this reaction, a 1 atm pressure of nitrogen gas can be used and the reaction proceeds at room temperature. The procedure is very simple. A THF solution of TiCl4 or Ti(O iPr)4 (1 equiv.), Li (10 equiv.), and TMSCl (10 equiv.) was stirred under an atmosphere of nitrogen at room temperature overnight to give titanium-nitrogen complexes. Although the structures of the titanium-nitrogen complexes have not yet been determined, they would consist of N(TMS)3, X2TiN(TMS)2, and XTi=NTMS. Using this procedure, various heterocycles, such as indole, quinoline, pyrrole, pyrrolizine, and indolizine derivatives, could be synthesized from molecular nitrogen in good-to-moderate yields as a stoichiometric reaction based on a titanium complex by a one-pot reaction. Furthermore, monomorine I and pumiliotoxin C were synthesized from molecular nitrogen as a nitrogen source. This procedure was further extended for the syntheses of heterocycles using a catalytic amount of titanium complex; also, indole and pyrrole derivatives were obtained in high yields.
Reduction of Oximes and Aliphatic Nitro Compounds to Imines for Further in situ Reactions: A Novel Synthesis of Pyrroles and Pyrrolin-2-ones
Barton, Derek H. R.,Motherwell, William B.,Simon, Ethan S.,Zard, Samir Z.
, p. 2243 - 2252 (2007/10/02)
Tributhylphosphine-diphenyl disulphide is a self-drying reagent capable of reducing ketoximes and secondary aliphatic nitro compounds to the corresponding imines under strictly anhydrous conditions at room temperature.The imine may be hydrolysed to a ketone, acetylated to give an enamide, reduced to an amine , or captured by hydrogen cyanide to produce an α-amino nitrile.In the case of 1,4-nitro ketones or esters, intramolecular cyclisation leads to pyrroles or pyrrolin-2-ones.Aldoximes and primary nitro compounds are converted into nitriles by the reagent.Hydroxamic acids are reduced to the corresponding amides.
A MILD REDUCTION OF ALIPHATIC NITRO COMPOUNDS TO IMINES FOR FURTHER IN SITU REACTIONS : A SIMPLE SYNTHESIS OF PYRROLES
Barton, Derek H. R.,Motherwell, William B.,Zard, Samir Z.
, p. 3707 - 3710 (2007/10/02)
Tributylphosphine-diphenyldisulphide reduces nitroalkanes to imines which can be trapped intramolecularly to give pyrroles.
