In:
Science, American Association for the Advancement of Science (AAAS), Vol. 308, No. 5730 ( 2005-06-24), p. 1890-1892
Abstract:
The binuclear copper enzyme tyrosinase activates O 2 to form a μ-η 2 :η 2 -peroxodicopper(II) complex, which oxidizes phenols to catechols. Here, a synthetic μ-η 2 :η 2 -peroxodicopper(II) complex, with an absorption spectrum similar to that of the enzymatic active oxidant, is reported to rapidly hydroxylate phenolates at –80°C. Upon phenolate addition at extreme temperature in solution (–120°C), a reactive intermediate consistent with a bis-μ-oxodicopper(III)-phenolate complex, with the O–O bond fully cleaved, is observed experimentally. The subsequent hydroxylation step has the hallmarks of an electrophilic aromatic substitution mechanism, similar to tyrosinase. Overall, the evidence for sequential O–O bond cleavage and C–O bond formation in this synthetic complex suggests an alternative intimate mechanism to the concerted or late stage O–O bond scission generally accepted for the phenol hydroxylation reaction performed by tyrosinase.
Type of Medium:
Online Resource
ISSN:
0036-8075
,
1095-9203
DOI:
10.1126/science.1112081
Language:
English
Publisher:
American Association for the Advancement of Science (AAAS)
Publication Date:
2005
detail.hit.zdb_id:
128410-1
detail.hit.zdb_id:
2066996-3
detail.hit.zdb_id:
2060783-0
SSG:
11
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