Primozic, Johann Julius (2024)
Mechanistic Investigation of the Diastereodivergent Asymmetric Allylic Alkylation of Cyclobutenes.
Technische Universität Darmstadt
doi: 10.26083/tuprints-00026531
Ph.D. Thesis, Primary publication, Publisher's Version
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Item Type: | Ph.D. Thesis | ||||
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Type of entry: | Primary publication | ||||
Title: | Mechanistic Investigation of the Diastereodivergent Asymmetric Allylic Alkylation of Cyclobutenes | ||||
Language: | English | ||||
Referees: | Thiele, Prof. Dr. Christina Marie ; Didier, Prof. Dr. Dorian ; Maulide, Prof. Dr. Nuno | ||||
Date: | 7 March 2024 | ||||
Place of Publication: | Darmstadt | ||||
Collation: | VIII, 301 Seiten | ||||
Date of oral examination: | 18 December 2023 | ||||
DOI: | 10.26083/tuprints-00026531 | ||||
Abstract: | The Pd-catalyzed asymmetric allylic alkylation of cyclobutenes with stabilized nucleophiles represents a unique example of a diastereodivergent deracemization and de-epimerization. In the present work, a comprehensive mechanistic analysis is reported, encompassing the preparation of putative Pd–allyl intermediates, ¹H/³¹P-NMR reaction monitoring, ²H-labeling studies, ESI-HRMS analysis of reaction mixtures, kinetic rate order determination, and ²H/¹³C-KIE studies. As a result, an unprecedented mechanistic scenario with a stereochemical dichotomy for both oxidative addition and nucleophilic attack is proposed. Oxidative addition exhibits a convergent course, allowing for de-epimerization to a rapidly interconverting mixture of η¹- and η³-coordinated Pd–allyl intermediates with the η1-species as resting states of the reaction. This suprafacial η¹–η³–η¹ equilibrium enables deracemization via a dynamic kinetic asymmetric transformation type I. Nucleophilic attack of displays a ligand-controlled divergent behavior, establishing a diastereodivergent access to enantioenriched products. |
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Status: | Publisher's Version | ||||
URN: | urn:nbn:de:tuda-tuprints-265315 | ||||
Classification DDC: | 500 Science and mathematics > 540 Chemistry | ||||
Divisions: | 07 Department of Chemistry > Clemens-Schöpf-Institut > Organ Chemistry | ||||
Date Deposited: | 07 Mar 2024 12:36 | ||||
Last Modified: | 08 Mar 2024 07:28 | ||||
URI: | https://tuprints.ulb.tu-darmstadt.de/id/eprint/26531 | ||||
PPN: | 516073192 | ||||
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