title: One-pot Zn/CuI/TFA-catalyzed domino three-component-carbocyclization reaction involving biphenyl-2-carbaldehydes/alkynes/piperidine: allenes-mediated construction of phenanthrenes.
abstract: A one-pot protocol involving Zn/CuI/TFA-catalyzed domino three-component and subsequent carbocyclization reactions is described. The reaction proceeds via formation of propargyl amines from biphenyl-2-carbaldehydes/terminal alkynes/piperidine followed by the elimination of piperidine and ring closure to furnish phenanthrene derivatives in good yields. The strategy involves C(sp)-H activation-CH functionalization with imine-alkyne activation-1,5 hydride shift-β-elimination of piperidine-allene formation-6π cycloaddition-isomerization domino sequence. Evidence for the involvement of allenes as an intermediate during carbocyclization is discussed.
authors: Medicinal & Process Chemistry Division, Central Drug Research Institute, CSIR, Lucknow 226 001, India.
authors: Mohammad
authors: M
authors: Saifuddin
authors: Piyush K
authors: PK
authors: Agarwal
authors: Bijoy
authors: B
authors: Kundu
mesh_terms: D000447:Aldehydes / Q000737:chemistry; D000466:Alkadienes / Q000737:chemistry*; D000480:Alkynes / Q000737:chemistry; D002384:Catalysis; D003300:Copper; D003500:Cyclization; D007097:Imines / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D010616:Phenanthrenes / Q000138:chemical synthesis*; D010880:Piperidines / Q000737:chemistry; D014269:Trifluoroacetic Acid; D015032:Zinc
chemical_list: D000447:Aldehydes; D000466:Alkadienes; D000480:Alkynes; D007097:Imines; D010616:Phenanthrenes; D010880:Piperidines; D003300:Copper; D014269:Trifluoroacetic Acid; D015032:Zinc