The enzymes tyrosinase and laccase from a crude extract of the button mushroom (Agaricus bisporus) can be employed to catalyze the domino reaction between phenol and various cyclic 1,3-dicarbonyls using atmospheric oxygen as the oxidizing agent and yielding annulated benzofuranes in a highly efficient and sustainable manner.
Laccase initiated domino reactions of cyclohexane-1,3-diones with catechols using air as an oxidant afford 3,4-dihydro-7,8-dihydroxy-2H-dibenzofuran-l -ones with yields ranging from 70% to 97%. (C) 2007 Elsevier Ltd. All rights reserved.