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Pseudo Cs-Symmetric Heterometallic Bissalen Complexes: Scaling up

Armengol, Helena LU (2016) KEMP31 20161
Department of Chemistry
Abstract
In this project work, we report the scaling up of the production of pseudo Cs-symmetric catalysts for asymmetric ring opening (ARO) of epoxides. These catalysts consists in heterometallic bissalen complexes whose synthesis has already been designed by our research group. Further research will be based on catalytic studies of the synthetized pseudo Cs-symmetric bissalen complexes in ARO of epoxides with TMSN3.
Popular Abstract
Salens are tetradentate ligands that, when asymmetric and in metallic complexes, can be used as catalysts in asymmetric ring opening (ARO) of epoxides.[1] Observing that dimeric salens, i.e. two salen cavities united by an hydrocarbonated chain, were better catalysts for these reactions, i.e. gave better yielding and same or even more enantiomeric excess,[2] the mechanism of the catalytic process was redefined. Metal salen complexes do not only perform as Lewis acids by activating the oxygen in the epoxide but also they activate the nucleophile in the ARO process.

The bissalen ligands used in these reactions were C2-symmetric, i.e. they had the same stereochemical configuration in both salen cavities.[3] The aim of the group research... (More)
Salens are tetradentate ligands that, when asymmetric and in metallic complexes, can be used as catalysts in asymmetric ring opening (ARO) of epoxides.[1] Observing that dimeric salens, i.e. two salen cavities united by an hydrocarbonated chain, were better catalysts for these reactions, i.e. gave better yielding and same or even more enantiomeric excess,[2] the mechanism of the catalytic process was redefined. Metal salen complexes do not only perform as Lewis acids by activating the oxygen in the epoxide but also they activate the nucleophile in the ARO process.

The bissalen ligands used in these reactions were C2-symmetric, i.e. they had the same stereochemical configuration in both salen cavities.[3] The aim of the group research in this project is to prove that meso ligands, when coordinated to two different metals thus affording Cs-symmetric complexes, can also perform as catalysts in ARO of epoxides giving good yields and high enantiomeric excess. It is a proof-of-concept project: meso complexes, which only break the symmetry by coordinating to different metal ions, can catalyse almost enantioselective ARO of epoxides. (Less)
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author
Armengol, Helena LU
supervisor
organization
course
KEMP31 20161
year
type
L3 - Miscellaneous, Projetcs etc.
subject
keywords
organic chemistry, organisk kemi
language
English
id
8880668
date added to LUP
2016-08-30 11:13:28
date last changed
2016-08-30 11:13:28
@misc{8880668,
  abstract     = {In this project work, we report the scaling up of the production of pseudo Cs-symmetric catalysts for asymmetric ring opening (ARO) of epoxides. These catalysts consists in heterometallic bissalen complexes whose synthesis has already been designed by our research group. Further research will be based on catalytic studies of the synthetized pseudo Cs-symmetric bissalen complexes in ARO of epoxides with TMSN3.},
  author       = {Armengol, Helena},
  keyword      = {organic chemistry,organisk kemi},
  language     = {eng},
  note         = {Student Paper},
  title        = {Pseudo Cs-Symmetric Heterometallic Bissalen Complexes: Scaling up},
  year         = {2016},
}