Activation of C-H bonds in thiophenes by Rh(PMe3)2(CO)Cl

A low-temperature NMR study

Martin G. Partridge, Leslie D. Field*, Barbara A. Messerle

*Corresponding author for this work

Research output: Contribution to journalArticle

15 Citations (Scopus)

Abstract

Irradiation of trans-Rh(PMe3)2(CO)Cl (1) at 230 K in the presence of 2,5-dimethylthiophene or thiophene affords products arising from C-H insertion. Irradiation of 1 in 2,5-dimethylthiophene affords three products: two conformers of the six-coordinate complex trans-Rh(PMe3)2(CO)(Cl)(2,5-dimethyl-3-thienyl)H, related by rotation about the Rh-C bond, and trans-Rh(PMe3)2(CO)(2,5-dimethyl-3-thienyl). The major conformer of trans-Rh(PMe3)2-(CO)(Cl)(2,5-dimethyl-3-thienyl)H decays back to 1 at a rate of (2.9 ± 0.2) × 10-4 s-1 at 273 K, whereas the minor conformer and trans-Rh(PMe3)2(CO)(2,5-dimethyl-3-thienyl) are relatively stable. Irradiation of (1) in the presence of thiophene affords products arising from addition at both the 2- and 3-positions in the thiophene ring: trans-Rh(PMe3)2(CO)-(Cl)(2-thienyl)H, Rh(PMe3)2(CO)(Cl)(3-thienyl)H and trans-Rh(PMe3)2(CO)(2-thienyl). The six-coordinate Rh(III) species each exist as two rotamers at 230 K related by rotation about the Rh-Caryl bond. Irradiation of 1 in thiophene or 2,5-dimethylthiophene under nitrogen with UV light at low temperatures also gives rise to products arising from thiophene carbonylation.

Original languageEnglish
Pages (from-to)872-877
Number of pages6
JournalOrganometallics
Volume15
Issue number2
Publication statusPublished - 23 Jan 1996
Externally publishedYes

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