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@PHDTHESIS{Teeuwen:1017213,
author = {Teeuwen, Simon},
othercontributors = {Leitner, Walter and Bolm, Carsten},
title = {{C}hirale {P}hosphin-{P}hosphoramidit-{L}iganden:
{S}ynthese und {A}nwendung in der asymmetrischen {K}atalyse},
school = {RWTH Aachen University},
type = {Dissertation},
address = {Aachen},
publisher = {RWTH Aachen University},
reportid = {RWTH-2025-07211},
pages = {1 Online-Ressource : Illustrationen},
year = {2025},
note = {Veröffentlicht auf dem Publikationsserver der RWTH Aachen
University; Dissertation, RWTH Aachen University, 2025},
abstract = {The core of this work deals with chiral hybrid bidentate
phosphine-phosphoramidite ligands regarding their
characteristics, employable synthetic methods and their
applicability in transition metal catalyzed asymmetric
transformations. The focus lies on the modularity of the
desired ligand structure and its possible structural
variations. In this work, 21 novel ligand structures are
reported, described and characterized. In the first
subdivision of this work, different synthetic methods of the
phosphine-phosphoramidite structures from phosphine-imines
are investigated. Due to stereo induction during the
reactions, the respective reaction steps of alkylation or
arylation are evaluated with regards to the obtained
diastereoselectivities. With the employment of structural
motifs with the possibility of undergoing secondary
ligand-substrate-interactions, their influence on asymmetric
catalysis is investigated. Additionally, methods for a
simple isolation of the desired structures are developed.
Due to all phosphine-phosphoramidites synthesized being
newly described in this work, their complete
characterization is carried out by using common analytical
practices such as NMR spectroscopy, mass spectrometry and
polarimetry. Via XRD crystal structure analysis the absolute
stereo configuration of formed diastereomers can be proven.
In addition, complexation of the new ligands on the
transition metal precursor complexes [Rh(acac)(CO)2],
[Rh(cod)2]BF4 and [Ir(cod)Cl]2 allows for examining their
developed coordinative behavior. This work’s second
subdivision includes the exploration of the new ligand
structures regarding their performance in the asymmetric
hydrogenation of olefins and imines, as well as the
asymmetric hydroformylation of benchmark substrates.
Secondary ligand-substrate interactions and a resulting
influence on enantioselectivity could not be observed from
the data available. Excellent enantioselectivities of up to
$98.0\%$ ee for N-acetyl phenylalanine methyl ester are
obtained in asymmetric hydrogenation. A moderate
matched-mismatched-effect is observed for ligand derivatives
with alternating stereo configurations. Asymmetric
hydroformylation of styrene is carried out with very good
branched/linear ratios up to $96.2\%$ and
enantioselectivities up to $86.9\%$ ee. The hydroformylation
results show a pronounced matched-mismatched-effect, which
is directly opposed to that observed for asymmetric
hydrogenation, rendering one ligand superior in one
transformation while its counterpart shows better
performance in the other transformation.},
cin = {154110 / 150000},
ddc = {540},
cid = {$I:(DE-82)154110_20140620$ / $I:(DE-82)150000_20140620$},
typ = {PUB:(DE-HGF)11},
doi = {10.18154/RWTH-2025-07211},
url = {https://publications.rwth-aachen.de/record/1017213},
}
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