Author, as appears in the article.: Margalef J, Borràs C, Alegre S, Pàmies O, Diéguez M

Department: Química Física i Inorgànica

URV's Author/s: ALEGRE ARAGONÉS, SABINA / BORRÀS NOGUERA, CARLOTA / Diéguez Fernández, Montserrat / Pamies Ollé, Oscar

Keywords: Versatile Thioether P,n-ligands Oxazoline ligands Etherification Enantioselectivity Chiral ligands Amination Allylation Alkylation

Abstract: A large library of thioether/selenoether-phosphite ligands have been tested in the Pd-catalyzed asymmetric allylic substitution reaction. The presented ligands are derived from cheap and available carbohydrates and they are air-stable solids and easy to handle. Their highly modular nature has made it possible to achieve excellent enantioselectivities in the substitution of a range of hindered and unhindered substrates (ees up to 99% and 91%, respectively). In addition, twelve C-, N- and O-nucleophiles can be efficiently introduced, independently of their nature. Among the whole library, ligands that contain an additional chiral centre in the alkyl backbone chain next to the phosphite group and an enantiopure biaryl phosphite group provided the best enantioselectivities. In general, there is a cooperative effect between these two chiral elements, and therefore, a matched combination between them is necessary to achieve the highest enantioselectivities. However, in the case of cyclic substrates, this cooperative effect is less pronounced and advantageously, both enantiomers of the product can be obtained by setting up the desired configuration of the biaryl phosphite group. Studies of the key Pd-π-allyl intermediates allowed us to better understand the enantioselectivities obtained experimentally.

Thematic Areas: Química Odontología Medicina ii Materiais Interdisciplinar Inorganic chemistry General medicine Farmacia Ensino Engenharias iv Engenharias iii Engenharias ii Engenharias i Ciências biológicas ii Ciências biológicas i Ciências ambientais Ciências agrárias i Chemistry, inorganic & nuclear Biotecnología Astronomia / física

licence for use: https://creativecommons.org/licenses/by/3.0/es/

ISSN: 14779226

Author's mail: montserrat.dieguez@urv.cat oscar.pamies@urv.cat

Author identifier: 0000-0002-8450-0656 0000-0002-2352-8508

Last page: 12643

Record's date: 2023-02-18

Journal volume: 48

Papper version: info:eu-repo/semantics/acceptedVersion

Link to the original source: https://pubs.rsc.org/en/content/articlelanding/2019/DT/C9DT02338K#!divAbstract

Licence document URL: http://repositori.urv.cat/ca/proteccio-de-dades/

Papper original source: Dalton Transactions. 48 (33): 12632-12643

APA: Margalef J, Borràs C, Alegre S, Pàmies O, Diéguez M (2019). A readily accessible and modular carbohydrate-derived thioether/selenoether-phosphite ligand library for Pd-catalyzed asymmetric allylic substitutions. Dalton Transactions, 48(33), 12632-12643. DOI: 10.1039/c9dt02338k

Article's DOI: 10.1039/c9dt02338k

Entity: Universitat Rovira i Virgili

Journal publication year: 2019

First page: 12632

Publication Type: Journal Publications