100562-44-5Relevant academic research and scientific papers
Pd-catalyzed C–H bond activation of Indoles for Suzuki reaction
Banerjee, Isita,Ghosh, Keshab Ch,Sinha, Surajit
, (2019)
Abstract: We present a practical method for Suzuki coupling by which unprotected or N-protected indoles may be selectively arylated in the C2-position through direct C–H bond activation by electrophilic Pd(TFA) 2 catalyst. The protocol is operationally simple as it is carried out in dioxane/water mixture, and air as the sole oxidant at room temperature. Various 2-arylated indoles were obtained in good yields. The protocol works for benzofuran, pyrrole and thiophene also. Graphic abstract: Selective C-2 arylation of heterocycles using Pd(II) catalyst via C–H activation was performed under ambient condition. C3–C2 migration of organopalladium intermediate controls the reaction pathway.[Figure not available: see fulltext.].
Synthesis and Catalytic Use of Polar Phosphinoferrocene Amidosulfonates Bearing Bulky Substituents at the Ferrocene Backbone
Vosáhlo, Petr,Radal, Leá,Labonde, Marine,Císa?ová, Ivana,Roger, Julien,Pirio, Nadine,Hierso, Jean-Cyrille,?těpni?ka, Petr
, p. 1934 - 1944 (2021)
Anionic phosphinoferrocene amidosulfonates bearing sterically demanding tert-butyl substituents in positions 3 and 3′ of the ferrocene scaffold, viz. rac-(Et3NH)[Fe(η5-tBuC5H3PR2)(η5-tBuC5H3C(O)NHCH2SO3)] (R = phenyl, cyclohexyl), were synthesized by amidation of the corresponding phosphinocarboxylic acids, [Fe(η5-tBuC5H3PR2)(η5-tBuC5H3CO2H)]. These ditopic polar phosphinoferrocenes and their non-tert-butylated analogues have been used as ligands to prepare zwitterionic (η3-allyl)palladium(II) complexes [Pd(η3-C3H5){Fe(η5-R′C5H3PR2)(η5-R′C5H3C(O)NHCH2SO3)}] (R′ = H, tBu; R = Ph, Cy). Depending on the isolation procedure and crystallization conditions, some complexes were isolated in two isomeric forms which differed in the coordination of the amidosulfonate pendant group, where either amide or sulfonated oxygen ligated the Pd(II) center. The preference for coordination of the amide or sulfonate oxygen atoms has been explained by the interplay of electrostatic and solvation effects and further supported by DFT calculations. The (η3-allyl)PdII complexes have been applied as defined precatalysts for Pd-catalyzed C-H arylation of an unprotected indole with aryl iodides in polar solvents. Under the optimized reaction conditions at 100 °C in water, C2-arylation proceeded selectively with various aryl iodides to produce the respective 2-arylindoles in acceptable yields at a low catalyst loading (1 mol % Pd) and in the absence of any phase transfer agent. The catalyst possessing tert-butyl groups at the ferrocene core and an electron-rich dicyclohexylphosphino group exhibited the best catalytic performance.
Multi-site cyclization via initial C-H activation using a rhodium(III) catalyst: Rapid assembly of frameworks containing indoles and indolines
Huang, Ji-Rong,Qin, Liu,Zhu, Yu-Qin,Song, Qiang,Dong, Lin
supporting information, p. 2844 - 2847 (2015/03/05)
Tandem multi-site cyclization triggered by Rh(III)-catalyzed C-H activation has been achieved for highly efficient synthesis of spirocycle indolin-3-one (C2-cyclization), benzo[a]carbazole (C3-cyclization) and an unusual indoxyl core (N1-cyclization). In particular, the synthesis of pseudo-indoxyl is typically completed within 10 min, and the reaction tolerates air, water and a range of solvents.
Copper-catalyzed N-arylation/hydroamin(d)ation domino synthesis of indoles and its application to the preparation of a Chekl/KDR kinase inhibitor pharmacophore
Ackermann, Lutz,Barfuesser, Sebastian,Potukuchi, Harish K.
supporting information; experimental part, p. 1064 - 1072 (2010/03/03)
Inexpensive copper catalysts allow for efficient syntheses of N-aryl-, N-acyl-, or N-H-(aza)in-doles starting from ortho-alkynylbromoarenes. The broad scope of this domino N-arylation/hydro-amin(d)ation process is highlighted by the synthesis of highly fu
