Intramolecular Hydroamination of Difluoropropargyl Amides: Regioselective Synthesis of Fluorinated β- and γ-Lactams
摘要:
Functionalized gem-difluoro beta- and gamma-lactams were synthesized through a novel intramolecular hydroamination reaction of difluoropropargyl amides.beta-Lactams were obtained via a Baldwin disfavored 4-exo-digonal cyclization using palladium acetate as the catalyst, whereas gamma-lactams were produced under basic conditions. Acid hydration of gamma-lactams produced ketoamides or hemiaminals selectively.
Intramolecular Hydroamination of Difluoropropargyl Amides: Regioselective Synthesis of Fluorinated β- and γ-Lactams
摘要:
Functionalized gem-difluoro beta- and gamma-lactams were synthesized through a novel intramolecular hydroamination reaction of difluoropropargyl amides.beta-Lactams were obtained via a Baldwin disfavored 4-exo-digonal cyclization using palladium acetate as the catalyst, whereas gamma-lactams were produced under basic conditions. Acid hydration of gamma-lactams produced ketoamides or hemiaminals selectively.
Stoichiometric and catalytic intermolecularPauson−Khandreactions (PKRs) of dissymmetric fluorinated alkynes were performed, affording regioselectively α-fluorinated cyclopentenones. Ethyl 4,4,4-trifluorobutynoate was an excellent substrate; its reaction with norbornadiene gave the corresponding PKR adduct in good yield and complete regioselectivity. Conjugate addition of nitroalkanes or cyanide to