Monoamine oxidase B (MAO-B) metabolizes monoamines such as dopamine regarding neural transmission and controls its level in the mammalian's brain. When MAO-B metabolizes dopamine abnormally, normal neurotransmission does not occur, and central nervous system disorders such as Parkinson's disease may develop. Although several MAO inhibitors have been developed, most of them have no selectivity between monoamine oxidase A (MAO-A) and MAO-B, or they work irreversibly against the enzyme. This report describes the first case of screening of <i>N</i>-arylated heliamine derivatives to develop novel MAO-B selective inhibitors that can be synthesized concisely by microwave-assisted Pd nanoparticle-catalyzed Buchwald-Hartwig amination. We discovered that the derivatives <b>4h</b>, <b>4i</b>, and <b>4j</b> display inhibitory activity against MAO-B with IC<sub>50</sub> values of 1.55, 13.5, and 5.08 μM, respectively.