1: tetrahydrofuran / -78 - 20 °C / Molecular sieve; Inert atmosphere 2: [copperl(II)(1,1,1,5,5,5-hexafluoroacetylacetonate)2] monohydrate; oxygen / N,N-dimethyl-formamide / 10 h / 105 °C View Scheme

in ethanol

0.25 h;