The present invention provides Janus kinase inhibitors, such as compounds of Formula (I) and Formula (II) wherein RY1 and RY2 comprise a tagged hydrophobic moiety RH. The compounds may covalently or non-covalently bind a kinase (e.g., Janus kinase 3 (JAK3)). The hydrophobic moiety RH may signal to the intracellular protein homeostasis machinery to induce degradation of the targeted kinase. Also provided are pharmaceutical compositions, kits, methods, and uses that involve the compounds for reducing the activity of a kinase and/or treating and/or preventing a condition associated with aberrant activity of a kinase (e.g., a proliferative disease, inflammatory disorder, autoimmune disorder, painful condition, and/or viral infection).