title: Synthesis, transformations, and comparative studies of porphyryl acrylic acids and their homologues.
abstract: The reactivity of porphyryl acrylates and their homologues was studied systematically and to establish their potential as building blocks for the synthesis of novel tetrapyrroles. A new synthetic approach for multifunctional porphyrins was developed using alpha,beta-unsaturated acyl porphyrins as versatile building blocks with yields of 44-95%. The reaction of acyl chlorides generated in situ with ethyl diazoacetate in the presence of PPh(3) led to the corresponding phosphazine, which was quickly self-transformed into a novel porphyrin beta-keto ester system in up to 78% yield. Comparative studies of the next homologue of acrylic porphyrins, i.e., those bearing an additional CH(2) group next to the double bond of the alpha,beta-unsaturated fragment, showed that these can undergo rearrangement reactions via vinylketenes to yield both regioisomers. Depending on the reaction conditions, this method gives regioselectively access to either a rearrangement product or the product of esterification reactions in yields of 81% or 57%, respectively. Enyne metathesis of novel propargyl esters with allyl porphyrins provided an easy access to 1,3-disubstituted butadienes in up to 76% yield.
authors.affiliation: School of Chemistry, SFI Tetrapyrrole Laboratory, Trinity College Dublin, Dublin 2, Ireland.
authors.forename: Natalia N
authors.initials: NN
authors.lastname: Sergeeva
authors.forename: Mohd B
authors.initials: MB
authors.lastname: Bakar
authors.forename: Mathias O
authors.initials: MO
authors.lastname: Senge
mesh_terms: D000179:Acrylates / Q000138:chemical synthesis* / Q000737:chemistry; D002712:Chlorides / Q000737:chemistry
chemical_list: D000179:Acrylates; D002712:Chlorides; C036658:acrylic acid