The invention provides compounds with activity against infectious diseases. The compounds of the invention may inhibit retroviral reverse transcriptases and thus inhibit the replication, of the virus. The compounds of the invention may be useful for treating human patients infected with a human retrovirus, such as human immunodeficiency virus (strains of HIV-l or HIV-2) or human T-cell leukemia virus (HTLV-1 or HTLV-II) which results in acquired immunodeficiency syndrome (AIDS) and/or related diseases. Representative of the invention is a compound of the following formula, with the substituents defined herein: ##STR00001##