Easily Prepared Chiral Scorpionates: Tris(2-oxazolinyl)boratoiridium(I) Compounds and Their Interactions with MeOTf

TitleEasily Prepared Chiral Scorpionates: Tris(2-oxazolinyl)boratoiridium(I) Compounds and Their Interactions with MeOTf
Publication TypeJournal Article
Year of Publication2008
AuthorsBaird B, Pawlikowski AV, Su J, Wiench JW, Pruski M, Sadow AD
Journal TitleInorganic Chemistry
Volume47
Pages10208-10210
Date PublishedNov
Type of ArticleArticle
ISBN Number0020-1669
Accession NumberISI:000260791100009
Keywordsasymmetric catalysis, C-H ACTIVATION, COMPLEXATION, COORDINATION CHEMISTRY, EFFICIENT, hapticity, IRIDIUM, ligands, metal, protonation, TRISOX
Abstract

Optically active C-3-symmetric monoanionic ligands are uncommon in organometallic chemistry. Here we describe the synthesis of readily prepared tris(4S-isopropyl-2-oxazolinyl)phenylborate [To(P)] and fluxional, zwitterionic four- and five-coordinate iridium(I) compounds [Ir(To(P))-(eta(4)-C8H12)] (4) and [Ir(To(P))(CO)(2)] (5). The highly fluxional nature of 4 and 5 makes structural assignment difficult, and the interaction between the iridium(I) center and the [To(P)] ligand is established by solid-state and solution N-15 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 Mel 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 H-1-N-15 HMBC experiments.

DOI10.1021/ic801637s
Alternate JournalInorg. Chem.