Suzuki‐Miyaura Reaction of Glycals with Base‐Labile Protecting Groups as a New Route to Glycoporphyrins

Abstract

AbstractGlycoporphyrins are considered promising photosensitisers of new generation. Herein, we describe a metal‐catalysed synthetic method towards porphyrin‐carbohydrate C−C conjugates. The protocol of Suzuki‐Miyaura reaction has been developed and it was compatible with peracetylated 2‐iodoglycals. The utility of the reaction was exemplified on 15 different (C‐2)‐arylated sugar derivatives. Then it was applied on more challenging starting materials, namely, porphyrin boronates in which we addressed the issues of difficult transmetalation step usually observed on palladium‐catalysed processes of porphyrin derivatives. The efficiency of the protocol was finally applied to synthesize the library of glycoporphyrins proving the versatile character of this strategy. Finally, the methodology was transferred onto A4‐type porphyrin to efficiently obtain an interesting example of a multivalent glycoconjugate.