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Formation of a C-C double bond from two aliphatic carbons. Multiple C-H activations in an iridium pincer complex

Polukeev, Alexey LU ; Marcos, Rocio; Ahlquist, Marten S. G. and Wendt, Ola LU (2015) In Chemical Science 6(3). p.2060-2067
Abstract
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,... (More)
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. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Chemical Science
volume
6
issue
3
pages
2060 - 2067
publisher
Royal Society of Chemistry
external identifiers
  • wos:000349832600060
  • scopus:84923167393
ISSN
2041-6539
DOI
10.1039/c4sc03839h
language
English
LU publication?
yes
id
abafab75-bd97-4511-803a-0b8e259515e0 (old id 5180082)
date added to LUP
2015-03-31 07:30:07
date last changed
2017-08-13 03:19:00
@article{abafab75-bd97-4511-803a-0b8e259515e0,
  abstract     = {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.},
  author       = {Polukeev, Alexey and Marcos, Rocio and Ahlquist, Marten S. G. and Wendt, Ola},
  issn         = {2041-6539},
  language     = {eng},
  number       = {3},
  pages        = {2060--2067},
  publisher    = {Royal Society of Chemistry},
  series       = {Chemical Science},
  title        = {Formation of a C-C double bond from two aliphatic carbons. Multiple C-H activations in an iridium pincer complex},
  url          = {http://dx.doi.org/10.1039/c4sc03839h},
  volume       = {6},
  year         = {2015},
}