Chemistry, Ames Laboratory
Journal or Book Title
Optically active C3-symmetric monoanionic ligands are uncommon in organometallic chemistry. Here we describe the synthesis of readily prepared tris(4S-isopropyl-2-oxazolinyl)phenylborate [ToP] and fluxional, zwitterionic four- and five-coordinate iridium(I) compounds [Ir(ToP)(η4-C8H12)] (4) and [Ir(ToP)(CO)2] (5). The highly fluxional nature of 4 and5 makes structural assignment difficult, and the interaction between the iridium(I) center and the [ToP] ligand is established by solid-state and solution 15N NMR methods that permit the direct comparison between solution and solid-state structures. Although iridium cyclooctadiene 4 is a mixture of four- and five-coordinate species, the dicarbonyl 5 is only the five-coordinate isomer. The addition of electrophiles MeOTf and MeI provides the oxazoline N-methylated product rather than the iridium methyl oxidative addition product. N-Methylation was unequivocally proven by through-bond coupling observed in 1H−15N HMBC experiments.
American Chemical Society
Baird, Benjamin; Pawlikowski, Andrew V.; Su, Jiachun; Wiench, Jerzy W.; Pruski, Marek; and Sadow, Aaron D., "Easily Prepared Chiral Scorpionates: Tris(2-oxazolinyl)boratoiridium(I) Compounds and Their Interactions with MeOTf" (2008). Chemistry Publications. 235.