Reactivity of 1,3,5-triaza-7-phosphaadamantane-6-yllithium (PTA-Li) Towards Organotin, Silicon, and Boron Chlorides

In this thesis, the synthesis and preliminary characterization of a library of 1,3,5-triaza-7-phosphaadamantane derivatives with Sn, Si, and B moieties are presented. Various electrophiles were reacted with lithiated PTA (PTA-Li) including SnR3Cl, SnR2Cl2, SiR2Cl2 (R=CH3, Ph), and BR2Cl (R=Cy, Ph). The &agr;-stannylated PTA, PTA-SnMe3, was successfully isolated along with the oxide, O=PTA-SnMe3, characterized through solution NMR (31P{ 1H}, 13C{1H}, 119Sn{ 1H}, and 1H) and ESI-MS. These water soluble compounds are also soluble in other organic solvents like chloroform, methylene chloride, hexanes, pentane, etc. PTA-SnMe3 has been found to oxidize in solution but is more stable in the solid state. Preliminary observations on the reactions of PTA-Li with other tin, silicon, and boron electrophiles show various side products that become more abundant upon increasing the reaction scale. This may be a consequence of the air and moisture sensitivity of the starting materials and the products. Attempts to isolate the products were limited by a small yield. Most of the compounds were observed to decompose into O=PTA. Future attempts should consider measures to test effective moisture removal from solvents and starting materials.