Allenylporphyrins: a new motif on the porphyrin periphery

Palladium-catalysed Suzuki–Miyaura cross-coupling proved to be the simplest and most efficient method for attaching an unsubstituted allene, a novel substituent and potential functional group, to the porphyrin periphery. Comparative studies on various allenyl synthetic pathways show that this method, which makes use of a bromoporphyrin and allenylboronate, affords the corresponding allenylporphyrin in the presence of an appropriate base and THF.