The present invention provides a new class of compounds useful for the modulation of beta-secretase enzyme (BACE) activity. The compounds have a general Formula I: wherein variables A1, A3, A5, A6, A8, R2, R7, X, Y and Z of Formula I are defined herein. The invention also provides pharmaceutical compositions comprising the compounds, and corresponding uses of the compounds and compositions for treatment of disorders and/or conditions related to plaque formation and deposition, resulting from the activity of BACE. Such BACE mediated disorders include, for example, Alzheimer's Disease, cognitive deficits and impairments, schizophrenia and other central nervous system conditions and disorders. The invention further provides compounds of Formulas II and III, and of sub-formulas of Formulas I, II and III, intermediates and processes and methods useful for the preparation of compounds of Formulas I-III.