(±)-tert-Butylphenylphosphinothioic acid was resolved into (Rp)-(+) tert-butylphenylphosphinothioic acids 129 according to a standard procedure. The (±)- and (Rp)-phosphinothioic acids were converted into (±)- and (Rp)-tert-butylphenylthionophosphinochloridates 139 respectively by treatment with either thionyl chloride or oxalyl chloride in dichloromethane, with enantiomeric purity for the (Rp)-product being in excess of 98%. Treatment of the chloridates with sodiated aryloxide or thio-aryloxide in DMF provided via a nucleophilic substitution reaction which proceeded with clean inversion to give O-phenyl (±)-tert-butylphenylthionophosphinate (±)-137, O-phenyl (Rp)-tert-butylphenylthionophosphinate (Rp)-137, S-phenyl (±)-tert-butylphenylthionophosphinate (±)-145, S-phenyl (Rp)-tert-butyl-phenylthionophosphinate (Rp)-145, O-1-naphthyl (±)-tert-butylphenylthionophosphinate (±)-142, O-1-naphthyl (Rp)-tert-butylphenylthionophosphinate (Rp)-142, O-2-naphthyl (±)-tert-butylphenylthionophosphinate (±)-143, O-2-naphthyl (Rp)-tert-butylphenylthionophosphinate (Rp)-143, O-(2-bromo-3-pyridyl) (±)-tert-butylphenylthionophosphinate (±)-141, O-(2-bromo-3-pyridyl) (Rp)-tert-butylphenylthionophosphinate (Rp)-141, S-2-bromophenyl (±)tert- butylphenylthionophosphinate (±)-146, and S-2-bromophenyl (Rp)-tert-butyl-phenylthionophosphinate (Rp)-146 in high yields. Similarly, each of pyrrole, indole and imidazole were deprotonated with sodium hydride and treated with each of (±)- and (Rp)-(±)-thionophosphinochloridate to give N-pyrrolyl (±)-tert-butylphenylthionophosphinoamidate (±)-153, (Rp)-tert-butylphenylthionophosphinoamidate (Rp)-153, N-indolyl (±)-tert-butylphenylthionophosphinoamidate (±)-154, N-indolyl (Rp)-tert- butylphenylthionophosphinoamidate (Rp)-154, and N-imidazolyl (±)-tert-butylphenylthionophosphinoamidate (±)-155, also in high yields. That inversion occurs in these reactions was confirmed by X-ray crystallographic determinations on compounds (Rp)-142 and (Rp)-145. The foregoing compounds were treated either with ...