A divergent and selective synthesis of ortho- and para-quinones from phenols

Tyrosinase and catechol oxidase activity of copper(I) complexes supported by imidazole-based ligands: structure–reactivity correlations

“…In 2013, Herres-Pawlis et al presented catalytic copper(I) model systems supported by bis(pyrazolyl)methane ligands which exhibit room temperature stable peroxo intermediates [20]. More recently, Lumb et al demonstrated catalytic conversions of different monophenols to a variety of organic products [21][22][23][24][25][26]. During the last years our group published a number of new copper(I) complexes functioning as model systems for tyrosinase [2,19,[27][28][29][30][31][32][33][34].…”

A bio-inspired synthesis of oxindoles by catalytic aerobic dual C–H functionalization of phenols

“…The cyclization of Q2 can be promoted by a variety of bases and cleanly returns Q3 and P1 ( Scheme 3B , entries 1–4). 29 Oxindoloquinone Q3 is the only observed product if Q2 is re-subjected to the standard catalytic conditions (entry 5), demonstrating that Q2 is a competent reaction intermediate in the transformation of P1 into Q3 , and that upon its release from Q2 , P1 can re-enter the catalytic cycle for conversion to Q3 . Cyclization of Q2 to Q3 is not promoted by acid (entry 6), suggesting that Q2 does not cyclize to an appreciable extent during the acidic work-up.…”

A Bioinspired Synthesis of Polyfunctional Indoles

“…ortho ‐Quinone Q1 differentiates its two carbonyl groups as an α,β‐unsaturated ketone and a vinylogous ester. Therefore, under carefully optimized conditions (see Tables S2–S5 in the Supporting Information), the vinylogous ester undergoes substitution with methanol to provide para ‐quinone Q3 with a methyl ether at C6 (indole numbering). This occurs with complementary regioselectivity to our previous work, which selectively functionalized the less electron rich carbonyl group at C5 .…”