Abstract
Cyclopentadienylidenetriphenylphosphorane (the Ramirez ylide), unexpectedly and contrary to a number of earlier reports, has been shown to be like pyrrole in undergoing electrophilic substitution on the cyclopentadienide ring at either the 3- or the 2-position, depending on the electrophile. Formylation under Vilsmeier conditions and addition of tetracyanoethylene occurs at the 3-position, while activated acetylenes and the nitrosyl electrophile substitute at the 2 position. The 3-formylated product was reduced to the 3-methyl derivative and it also reacted under Knoevenagel conditions to give a number of novel condensation products. The results of single-crystal X-ray crystallographic analyses are given for four of the compounds studied, and a careful 2D NMR analysis of all of the compounds was performed in order to develop a reliable method for the unambiguous assignment of the regiochemistry of adduct formation.
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.
