Redox neutral [4+1] cyclic reaction based on C-F fracture
Recently, Professor Feng Chao of the Institute of Advanced Synthesis of Nanjing University of Technology and Professor Rodeping of the School of Chemistry and Materials Science of USTC reported on the strategy of using C-F bond fracture under mild reaction conditions, through [4+1] a new method for constructing the important nitrogen-containing heterocyclic skeleton of indole ketone by cyclic reaction. It was found that α,α-Dimethylsulfoxide acetylene could participate in [4+1] cyclic reaction as an unconventional single carbon component under the condition that [RhCp*Cl2]2 is the precursor of catalyst, potassium acetate and 3Å molecular sieve as additive and methanol as reaction solvent. The multi-substituted indole ketone compounds containing the quaternary carbon center were synthesized and easily and quickly by high yield and single-minded region selectivity. The reaction is unique in the following three points: 1) two times the fracture of the C-F bond makes the whole reaction system exhibit the characteristics of redox neutrality, avoiding the use of the additive oxidizer; 2) due to the activation of the acetylene by Dimethylsulfoxide acetylene, the C-C and the C-N region are single-based on the same SP hybrid acetylene carbon atom; 3) due to the regional specificity of C-C bonding in this reaction and the fracture of C-F bond, the C≡C in the resulting product are migrated.
The research achievement was published in the JACS