[3 + 1] Mixed Cyclization: A Synthetic Route to Prepare Low-Symmetry Phthalocyanines

Abstract

A novel synthetic strategy for low-symmetry phthalocyanines has been developed, which involves the basepromoted cyclization of a preconnected trisphthalonitrile and a free phthalonitrile in the presence of a metal template. By using this [3 + 1] mixed cyclization approach, a series of zinc(II) phthalocyanine derivatives have been synthesized in up to 12% yields, including a very rare ABCD-type phthalocyanine and an amphiphilic ABACtype analogue that can self-assemble in aqueous media, forming stable spherical nanoparticles.

Bulking Up the Bay-Position Substituents Enables Enhanced Selectivity of Cs-Symmetric Boron Subphthalocyanine–Subnaphthalocyanine Hybrids

“…Therefore, this sterically driven strategy offers a simple yet still elegant route toward selective formation of π-extended Bsub-(Pc 3-p -Nc p ) hybrids, with potentially higher yields than other sophisticated methods used in phthalocyanine (Pc) chemistry. 46,47 Inspired by these precedents, we report the use of sterically driven mixed cyclotrimerization enabling precise control over the product distribution to two macrocyclic species for the selective formation of Bsub(Pc 2 -Nc 1 ) hybrids (Scheme 1C). The primary macrocycle from this process was the targeted nonsterically hindered C s -symmetric hybrid.…”

“…Theoretically, this type of mixed cyclotrimerization should demonstrate improved selectivity producing only two macrocycles that display minimal to no steric hindrance. Therefore, this sterically driven strategy offers a simple yet still elegant route toward selective formation of π-extended Bsub­(Pc 3‑ p -Nc p ) hybrids, with potentially higher yields than other sophisticated methods used in phthalocyanine (Pc) chemistry. , …”

“…Therefore, this sterically driven strategy offers a simple yet still elegant route toward selective formation of π-extended Bsub(Pc 3- p -Nc p ) hybrids, with potentially higher yields than other sophisticated methods used in phthalocyanine (Pc) chemistry. 46 , 47 …”