title: Merging C-H activation and alkene difunctionalization at room temperature: a palladium-catalyzed divergent synthesis of indoles and indolines.
abstract: A palladium-catalyzed 1,2-carboamination through C-H activation at room temperature is reported for the synthesis of 2-arylindoles, and indolines from readily available, inexpensive aryl ureas and vinyl arenes. The reaction initiates with a urea-directed electrophilic ortho palladation, alkene insertion, and β-hydride elimination sequences to provide the Fujiwara-Moritani arylation product. Subsequently, aza-Wacker cyclization, and β-hydride elimination provide the 2-arylindoles in high yields. Intercepting the common σ-alkyl-Pd intermediate, corresponding indolines are also achieved. The indoline formation is attributed to the generation of stabilized, cationic π-benzyl-Pd species to suppress β-hydride elimination.
authors: Chemistry Division, CSIR-Indian Institute of Chemical Biology , 4 Raja S. C. Mullick Road, Jadavpur, Kolkata 700032, West Bengal, India.
authors: Manash Kumar
authors: MK
authors: Manna
authors: Asik
authors: A
authors: Hossian
authors: Ranjan
authors: R
authors: Jana
mesh_terms: D000475:Alkenes; D002384:Catalysis; D003500:Cyclization; D007211:Indoles / Q000138:chemical synthesis* / Q000737:chemistry; D015394:Molecular Structure; D010165:Palladium / Q000737:chemistry*; D013696:Temperature; D014508:Urea / Q000737:chemistry*
chemical_list: D000475:Alkenes; D007211:Indoles; D010165:Palladium; C057812:indoline; D014508:Urea