Chemical Reactions

The nitrogen atom of an amine carries a lone pair of electrons, and it is this lone pair that governs almost everything amines do chemically. Because nitrogen is more electronegative than hydrogen, and because that unshared pair is readily available for sharing, amines behave both as nucleophiles (attacking electron-deficient centres) and as bases (accepting a proton). Whether an amine is primary ($\text{R-NH}_2$), secondary ($\text{R}_2\text{NH}$), or tertiary ($\text{R}_3\text{N}$) — that is, how many N–H bonds remain — also has a strong bearing on how a given reaction proceeds, since the presence or absence of an N–H hydrogen changes what kind of product can form. The r …