RESUMO
10-Arylbenzo[h]quinolines were synthesized by cross-coupling of ethyl benzo[h]quinoline-10-carboxylate with arylboronic acids via group-directed Ni(0) catalyzation. The catalytic system combining Ni(COD)2 (10 mol %) with PCy3 (20 mol %) and t-BuOK (3 equiv) was optimal for the above transformations. A series of arylboronic acids reacted with ethyl benzo[h]quinoline-10-carboxylates for the production of various substituted 10-phenyl[h]quinolines in moderate and good yields under optimized reaction conditions.
RESUMO
Carbon quantum dots (CQDs) are promising nanomaterials since they have smaller particle size, excellent biocompatibility, and low toxicity. However, no one has found their high-scale inhibition performance so far. In this article, a new kind of green scale inhibitor, carboxyl carbon quantum dots (CCQDs), was synthesized through a simple method of thermal decomposition of citric acid. The as-prepared CCQDs have excellent scale inhibition performance for CaSO4 and BaSO4. With a static test of scale inhibition at a temperature of 0-80 °C, the antiscaling efficiency can reach 100% with low additions of CCQDs.