Publications

Complexes of the form TpW(NO)(PMe₃)(η²-thiophene) have been synthesized in 31−40% yield by reduction of TpW(NO)(PMe₃)(Br) in the presence of the thiophene ligand. The dynamics of protonation and the subsequent deprotonation for the corresponding 2H-thiophenium complexes have been investigated. Hydrogenation of the uncoordinated double bond was accomplished, and sulfur−carbon, sulfur−oxygen, and carbon−carbon bond-forming reactions were explored with these complexes.

Arenes and aromatic heterocycles have cyclic skeletons made up completely of unsaturated carbons. Through their dihapto coordination to a transition metal, controlled addition reactions can be accomplished with good stereocontrol, relative to the position of the metal. The metal can readily undergo inter- and intrafacial linkage isomerizations in these complexes. By controlling these processes using chiral auxiliaries on the arene, stereogenic metal centers, or solid-state induced control of kinetically unstable stereoisomers (SICKUS), enantio-enriched organic compounds can be realized from this methodology. This work outlines what is known about conformational and linkage isomerizations in dihapto-coordinated aromatic complexes, and demonstrates their relevance to organic synthesis

Arene complexes of the form TpM(π-acid)(L)(η²-arene) (Tp = hydridotris(pyrazolyl)borate, M = Re, Mo, or W, π-acid = CO or NO, L = 1-alkylimidazole, pyridine, PMe₃, arene is prochiral) exist as a dynamic equilibrium of coordination diastereomers in solution. In both crystalline and amorphous solid states, however, only one diastereomer is present. Reactions on the bound arenes in these complexes have been performed stereoselectively, by exploiting the homomorphic nature of the solid phase.