Abstract
Cycloaddition reactions of acetylenic and olefinic dipolarophiles with diazoketones and a diazoester linked to tricarbonyl iron coordinaced diene units were investigated. 1H-pyrazoles were obtained directly from acetylene carboxylic esters by [1,5] group migrations at the stage of the primary formed 3H-pyrazoles. With methyl acrylate, the cycloaddition led to complexes of Δ 2-pyrazolines and at slightly more elevated temperature, with the diazoester, to cyclopropane esters. All diastereomers formed in each reaction could easily be separated by simple chromatography on silica gel, illustrating one of the practical advantages of the use of tricarbonyl iron complexes. In the optically active series, this allowed the high ee synthesis of various products with α-aminoacid or dienylcyclopropane substructures.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
