The present invention provides, in part, compounds of Formula I: or an N-oxide thereof, or a pharmaceutically acceptable salt of the compound or the N-oxide, wherein: R1, R2, L, A, and E are as described herein; processes for the preparation of; intermediates used in the preparation of; and compositions containing such compounds, N-oxides, or salts, and their uses for treating M4-mediated (or M4-associated) disorders including, e.g., Alzheimer's Disease, schizophrenia (e.g., its cognitive and negative symptoms), pain, addiction, and a sleep disorder.