Formation of a C-C double bond from two aliphatic carbons. Multiple C-H activations in an iridium pincer complex
2015 (English)In: Chemical Science, ISSN 2041-6520, Vol. 6, no 3, 2060-2067 p.Article in journal (Refereed) Published
The search for novel, atom-economic methods for the formation of C-C bonds is of crucial importance in synthetic chemistry. Especially attractive are reactions where C-C bonds are formed through C-H activation, but the coupling of unactivated, alkane-type C-sp3-H bonds remains an unsolved challenge. Here, we report iridium-mediated intramolecular coupling reactions involving up to four unactivated C-sp3-H bonds to give carbon-carbon double bonds under the extrusion of dihydrogen. The reaction described herein is completely reversible and the direction can be controlled by altering the reaction conditions. With a hydrogen acceptor present a C-C double bond is formed, while reacting under dihydrogen pressure leads to the reverse process, with some of the steps representing net C-sp3-C-sp3 bond cleavage. Mechanistic investigations revealed a conceptually-novel overall reactivity pattern where insertion or deinsertion of an Ir carbene moiety, formed via double C-H activation, into an Ir-C bond is responsible for the key C-C bond formation and cleavage steps.
Place, publisher, year, edition, pages
2015. Vol. 6, no 3, 2060-2067 p.
IdentifiersURN: urn:nbn:se:kth:diva-161629DOI: 10.1039/c4sc03839hISI: 000349832600060ScopusID: 2-s2.0-84923167393OAI: oai:DiVA.org:kth-161629DiVA: diva2:797641
QC 201503242015-03-242015-03-132015-03-24Bibliographically approved