Compounds having the following structure (I): including stereoisomers, prodrugs, and pharmaceutically acceptable salts, esters and solvates thereof, wherein R1, R2, R3a, R3b, L1, L2 and n are as defined herein. Such compounds generally function as H1 receptor ligands, and thus have utility as sleep inducing agents. Pharmaceutical compositions containing a compound of structure (I), as well as methods relating to the use thereof, are also disclosed.