Abstract
A facile introduction of alpha,beta- or alpha,beta,gamma,delta-unsaturated ester functions onto porphyrins was achieved through rhodium-catalyzed addition of beta-borylporphyrins to acrylate or 2,4-pentadienoate esters. The reaction of meso-borylporphyrins with acrylates exclusively afforded saturated esters by 1,4-conjugate addition under the same reaction conditions. Thus, the reaction mode (Heck-type versus conjugate addition) is highly dependent on the reaction site (beta versus meso). This functionalization has a significant impact on the electronic properties of the pi system of porphyrins, which induces a substantial redshift and broadening in the absorption spectra by effective conjugation through the beta positions. The coplanar structure of the unsaturated ester moieties with respect to the porphyrin core has been unambiguously elucidated by X-ray crystallographic analysis.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: 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.