Please use this identifier to cite or link to this item:
Title: Metal control of selectivity in acetate-assisted C-H bond activation : an experimental and computational study of heterocyclic, vinylic and phenylic C(sp[superscript 2])-H bonds at Ir and Rh
Authors: Carr, Kevin J. T
Davies, David L.
Macgregor, Stuart A.
Singh, Kuldip
Villa-Marcos, Barbara
First Published: 24-Mar-2014
Publisher: Royal Society of Chemistry
Citation: Chemical Science, 2014, 5 (6), pp. 2340-2346
Abstract: Acetate-assisted C(sp[superscript 2])–H bond activation at [MCl[subscript 2]Cp*][subscript 2] (M = Ir, Rh) has been studied for a series of N-alkyl imines, [superscript i]PrN[double bond, length as m-dash]CHR, (R _ N-methyl-2-pyrrolyl, H-L[subscript 1]; 2-furanyl, H-L[subscript 2]; 2-thiophenyl, H-L[subscript 3a]; C[subscript 2]H[subscript 2]Ph, H-L[subscript 4]; and Ph, H-L[subscript 5]) as well as phenylpyridine (H-L[subscript 6]) by both experimental and computational means. Competition experiments reveal significant variation in the relative reactivity of these substrates and highlight changes in selectivity between Ir (H-L[subscript 4] ≈ H-L[subscript 2] < H-L[subscript 3a] ≈ H-L[subscript 5] < H-L[subscript 1] ≈ H-L[subscript 6]) and Rh (H-L[subscript 2] ≈ H-L[subscript 1] < H-L[subscript 3a] ≈ H-L[subscript 4] < H-L[subscript 5] < H-L[subscript 6]). Comparison of H-L[subscript 3a] with its N-xylyl analogue, H-L[subscript 3b], gives a further case of metal-based selectivity, H-L[subscript 3a] being more reactive at Ir, while H-L[subscript 3b] is preferred at Rh. H/D exchange experiments suggest that the selectivity of C–H activation at Ir is determined by kinetic factors while that at Rh is determined by the product thermodynamic stability. This is confirmed by computational studies which also successfully model the order of substrate reactivity seen experimentally at each metal. To achieve the good level of agreement between experiment and computation required the inclusion of dispersion effects, use of large basis sets and an appropriate solvent correction.
DOI Link: 10.1039/c4sc00738g
ISSN: 2041-6520
eISSN: 2041-6539
Version: Post-print
Status: Peer-reviewed
Type: Journal Article
Rights: Copyright © the authors, 2014. This is an open-access article distributed under the terms of the Creative Commons Attribution License ( ), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
Appears in Collections:Published Articles, Dept. of Chemistry

Files in This Item:
File Description SizeFormat 
c4sc00738g.pdfPublished (publisher PDF)559.91 kBAdobe PDFView/Open

Items in LRA are protected by copyright, with all rights reserved, unless otherwise indicated.