Chlorination of aromatic substrates catalyzed by the phthalocyanine complexes

Abstract

The chlorination of benzene, toluene, and o xylene with molecular chlorine in the pres ence of the phthalocyanine complexes of different structures was studied. The transformations of the catalysts during the reaction were investigated.

Phthalocyanine Metal Complexes in Catalysis

“…245 Lewis acid properties of MPc t Bu 4 (M = Co, Ni, Pd, CrCl) were used for the catalytic chlorination of benzene, toluene, and oxylene with molecular chlorine. 247 Toluene was transformed in oand p-chlorotoluene with 0.05 mol % catalyst loading at 25 °C with up to 97% total yield (Scheme 58).…”

“…Phthalocyanine moieties of the complexes underwent chlorination during catalytic reactions. 247 Iron phthalocyanines bearing positively charged substituents mediated oxidative chlorination of aromatic compounds by H 2 O 2 −HCl. 248 Using 0.65 mol % catalyst loading, 2-methyl-1chloronaphthalene (94% chromatographic yield), 2-methoxy-1chloronaphthalene (99%), 2,3-dimethyl-1,4-dichloronaphthalene (95%), 2,6-dimethyl-1,5-dichloronaphthalene (95%), and 1-methyl-4,5-dimethoxy-2-chlorobenzene (99%) were prepared.…”

“…A complex mixture of 3- and 4-monochloro- o -xylenes (76% total yield in 10:1 ratio), dichloroxylenes (16% yield), and trichloroxylenes was obtained with 0.05 mol % CoPc t Bu 4 catalyst after 3.5 h. Chlorination of pyridine provided 3,5-dichloropyridine in 15% isolated yield after 5 h. On the basis of UV–vis data, the cation radical form of CoPc t Bu 4 was proposed to be the active species. Phthalocyanine moieties of the complexes underwent chlorination during catalytic reactions …”