Synfacts 2011(10): 1063-1063  
DOI: 10.1055/s-0030-1261103
Synthesis of Heterocycles
© Georg Thieme Verlag Stuttgart ˙ New York

Palladium-Catalyzed C-H Activation Induced Enantioselective Route to Fused Indolines

Contributor(s): Victor Snieckus, Emilie David
M. Nakanishi, M. Katayev, C. Besnard, E. P. Kündig*
University of Geneva, Switzerland
Further Information

Publication History

Publication Date:
20 September 2011 (online)


The synthesis of highly enantioenriched trans-fused indolines 2 is reported via Pd-catalyzed C-H activation in an unactivated methylene. The nucleophilic carbene NHC-HI proved to be the best precursor to generate the most efficient palladium-NHC catalyst for this transformation. Carrying out the reaction at lower catalyst loading (5 mol%), shorter reaction time (3 h) and higher temperature (160 ˚C) led to lower yields of products with minor effect on the enantiomeric ­excess. The reaction was successful with cyclohexyl- and cycloheptyl-substituted substrates 1 (n = 2, 3) but failed with cyclopentyl derivatives 1 (n = 1). A good range of substituents R was shown to be tolerated. The absolute configuration of the fused indolines 2 was determined by X-ray diffraction analysis. A mechanism was suggested without evidence.