The chlorination of b-halo or b,b-dihaloporphyrins with 2-chloro-1,3-bis(methoxycarbonyl)guanidine (Palau' Chlor) proceeded selectively at the neighboring unsubstituted meso position to affordmeso,b-dihalo or meso,b,b-trihaloporphyrins.S ucho ligohaloporphyrins are useful platforms for constructing more-elaborate porphyrin-based extended p systems.F or example,m eso-chloro-b,b-diiodoporphyrin participated in an efficient single-step synthesis of ad iphenylaminefused porphyrin. In addition, meso-chloro-b-iodoporphyrin was transformed in stepwise fashion into an efficiently conjugated meso-to-meso,b-to-b doubly butadiyne-linked porphyrin dimer,asystem which was previously difficult to access without such haloporphyrin precursors.Porphyrins are an important class of arenes in light of the wide range of applications that arise from their intriguing electronic and optical properties.[1] Peripheral functionalizations of porphyrins have attracted considerable attention since they allow the creation of av ariety of porphyrin-based functional materials.[2] In these recent studies,haloporphyrins play an important role as indispensable synthetic intermediates in reactions such as cross-coupling reactions, [3] aromatic nucleophilic substitution (S N Ar) reactions, [4] and peripheral metalations.[5] Therefore,d evelopment of an ew class of haloporphyrin intermediates should lead to an increase in the number of usable synthetic strategies and hence easier access to desirable porphyrin derivatives.Thee lectrophilic halogenation of porphyrins usually occurs selectively at their electron-rich meso positions to afford meso-haloporphyrins.[6] As ac omplementary method, we recently reported the facile preparation of meso-free bhaloporphyrins and b,b-dihaloporphyrins by Cu-mediated halogenation of b-borylporphyrins. [7, 8] These b-haloporphyrins allowed the synthesis of various functional porphyrins that were difficult to access without such precursors.[5d, 8] Herein, we disclose an efficient synthetic route to oligohaloporphyrins that bear more than two halogen substituents at the meso and neighboring b positions.T ot he best of our knowledge,t he efficient synthesis of such synthetic platforms has yet to be reported in the literature. [9] We thought that meso-free b-haloporphyrins were attractive precursors of meso,b-oligohaloporphyrins because of the presence of the reactive meso position. Attempted halogenation reactions of b-chloro Ni II porphyrin 1a with various halogenating reagents were carried out (see Table S1 in the Supporting Information). Bromination with N-bromosuccinimide (NBS) [6a] or iodination with ac ombination of I 2 and [bis(trifluoroacetoxy)iodo]benzene [6b] afforded the corresponding b-halo-b-chloroporphyrins 3 as unwanted side products.O nt he other hand, we found that both PhICl 2 [6c, 10] and 2-chloro-1,3-bis(methoxycarbonyl)guanidine (Palau' Chlor) [11] were efficient chlorinating reagents to provide meso,b-dichloroporphyrin 2aCl.C hen and co-workers reported that PhICl 2 was not suitable f...