The present invention is directed to compounds of formula (I): ##STR00001## wherein R.sub.1, R.sub.2 and R.sub.3 are independently selected from the group consisting of alkyl, alkenyl, alkynyl, cycloalkyl, aryl and heteroaryl and X.sub.1 and X.sub.2 are independently a bond or an linker group of 1 to 6 atoms and may be optional substituted or oxidized, or a prodrug, a pharmaceutically acceptable salt or a pharmaceutically active metabolite thereof. The invention is also directed to methods of using the same for treating HIV infections, or AIDs or preventing viral replication.