The present invention relates to methods of modulating (for example, inhibiting) activity of JAK3, comprising contacting the JAK3 with a compound of Formula I: or pharmaceutically acceptable salt thereof, wherein constituent members are provided hereinwith. The present invention further provides novel compounds and compositions as well as their methods of preparation and use of the same as JAK3 inhibitors in the treatment of JAK3-associated diseases including, for example, inflammatory and autoimmune disorders.