title: Synthesis of Novel Fluoropicolinate Herbicides by Cascade Cyclization of Fluoroalkyl Alkynylimines.
abstract: The cascade cyclization of fluoroalkyl alkynylimines with primary amines has been modified to allow the synthesis of 4-amino-5-fluoropicolinates. Use of N-trityl and acetal protecting groups in the cyclization precursor led to 5-fluoropyridines that were easily deprotected to picolinaldehyde derivatives for further elaboration to structures of interest as potential herbicides. This method provided access to picolinic acids with alkyl or aryl substituents at the 6-position that were previously inaccessible via cross-coupling chemistry.
authors.affiliation: †Discovery Chemistry and ‡Process Chemistry, Dow AgroSciences, 9330 Zionsville Road, Indianapolis, Indiana 46268, United States.
authors.forename: Peter L
authors.initials: PL
authors.lastname: Johnson
authors.affiliation: †Discovery Chemistry and ‡Process Chemistry, Dow AgroSciences, 9330 Zionsville Road, Indianapolis, Indiana 46268, United States.
authors.forename: James M
authors.initials: JM
authors.lastname: Renga
authors.affiliation: †Discovery Chemistry and ‡Process Chemistry, Dow AgroSciences, 9330 Zionsville Road, Indianapolis, Indiana 46268, United States.
authors.forename: Christopher V
authors.initials: CV
authors.lastname: Galliford
authors.affiliation: †Discovery Chemistry and ‡Process Chemistry, Dow AgroSciences, 9330 Zionsville Road, Indianapolis, Indiana 46268, United States.
authors.forename: Gregory T
authors.initials: GT
authors.lastname: Whiteker
authors.affiliation: †Discovery Chemistry and ‡Process Chemistry, Dow AgroSciences, 9330 Zionsville Road, Indianapolis, Indiana 46268, United States.
authors.forename: Natalie C
authors.initials: NC
authors.lastname: Giampietro
mesh_terms: D000631:Aminopyridines / Q000138:chemical synthesis* / Q000737:chemistry; D003500:Cyclization; D006540:Herbicides / Q000138:chemical synthesis* / Q000737:chemistry; D007097:Imines / Q000737:chemistry*; D015394:Molecular Structure; D010848:Picolinic Acids / Q000138:chemical synthesis* / Q000737:chemistry
chemical_list: D000631:Aminopyridines; D006540:Herbicides; D007097:Imines; D010848:Picolinic Acids