A New Substitution Pattern in Subphthalocyanines: Regioselective Synthesis and Separation of “ortho” Derivatives

Abstract

The regioselective preparation of ortho‐substituted subphthalocyanides was achieved employing 3‐substituted phthalonitrile derivatives as starting materials. A mechanistic proposal has been outlined.

Subphthalocyanines, Subporphyrazines, and Subporphyrins: Singular Nonplanar Aromatic Systems

“…These theoretical considerations on the mechanism of SubPc formation fit quite well with formerly reported experimental results. Thus, the proposed mechanistic pathway involving a dimeric intermediate made of two aza-fused phthalonitrile units explain the observed C 1 / C 3 selectivity described above . Additionally, these studies are in accordance with the experimentally determined optimal phthalonitrile/BCl 3 1:1 stoichiometry since the first step of the reaction necessarily involves the formation of a desymmetrized species which may act as both nucleophile and electrophile such as 7 .…”

“…Thus, the proposed mechanistic pathway involving a dimeric intermediate made of two aza-fused phthalonitrile units explain the observed C 1 /C 3 selectivity described above. 115 Additionally, these studies are in accordance with the experimentally determined optimal phthalonitrile/BCl 3 1:1 stoichiometry 23 since the first step of the reaction necessarily involves the formation of a desymmetrized species which may act as both nucleophile and electrophile such as 7. Torres and co-workers were able to isolate 8 (Scheme 6) as a white solid that most probably comes from the partial hydrolysis of 7 in the presence of moisture during the isolation process.…”

Optical resolution via chiral auxiliaries of curved subphthalocyanine aromatics

“…S23–S32 † ). 51 At this point, removal of the chiral auxiliary from the isolated diastereomers was expected to yield the enantiomerically pure P and M I 3 SubPc-Cl derivatives, as observed for meta -substituted m -3. However, treatment of o -2b with 20 equiv.…”

Recent advances in subphthalocyanines and related subporphyrinoids

“…As an example, 1.5 : 1, 1.75 : 1 and 1 : 9 C 3 : C 1 ratios have been observed in the presence of peripheral nitro, iodo and propylsulfonyl groups, respectively. 33 Notably, cyclotrimerization of 3-nitro-5- t -butylphthalonitrile afforded a mixture of C 3 and C 1 regioisomers in a 9 : 1 ratio, which substantially differs from the 1.5 : 1 ratio found in the synthesis of the ortho -(NO 2 ) 3 SubPc derivative. 31 In 2015, the regioselective synthesis of a C 3 -symmetric ortho -pentafluorosulfanylphenyl-substituted SubPc ( 7 , Fig.…”