Far-red fluorescence and chiroptical properties of pyrrolopyrrole aza-BODIPYs induced by the B,O-chelation.

A titanium-mediated aza-BODIPY synthesis using diketopyrrolopyrrole bearing o-anisyl substituents provided B,O-chelated pyrrolopyrrole aza-BODIPYs in a one-pot manner via ether bond cleavage and chelation of the resulting nucleophilic oxygen to the boron atom. The B,O-chelation not only induces the redshifts of absorption and fluorescence but also endows chiroptical properties.