Enantioconvergent Cu-Catalyzed Intramolecular C-C Coupling at Boron-Bound C(sp3) Atoms of α-Aminoalkylboronates Using a C1-Symmetrical 2,2'-Bipyridyl Ligand Attached to a Helically Chiral Macromolecular Scaffold

Enantioconvergent intramolecular coupling of α-(2-bromobenzoylamino)benzylboronic esters was achieved using a copper catalyst having helically chiral macromolecular bipyridyl ligand, PQXbpy. Racemic α-(2-bromobenzoylamino)benzylboronic esters were converted into (R)-configured 3-arylisoindolinones with high enantiopurity using right-handed helical PQXbpy as a chiral ligand in a toluene/CHCl3 mixed solvent. When enantiopure (R)- and (S)-configured boronates were separately reacted under the same reaction conditions, both afforded (R)-configured products through formal stereoinvertive and stereoretentive processes, respectively. From these results, a mechanism involving deracemization of organocopper intermediates in the presence of PQXbpy is assumed. PQXbpy switched its helical sense to left-handed when a toluene/1,1,2-trichloroethane mixed solvent was used, resulting in the formation of the corresponding (S)-products from the racemic starting material.

Medienart:

E-Artikel

Erscheinungsjahr:

2020

Erschienen:

2020

Enthalten in:

Zur Gesamtaufnahme - volume:142

Enthalten in:

Journal of the American Chemical Society - 142(2020), 43 vom: 28. Okt., Seite 18317-18323

Sprache:

Englisch

Beteiligte Personen:

Yoshinaga, Yukako [VerfasserIn]
Yamamoto, Takeshi [VerfasserIn]
Suginome, Michinori [VerfasserIn]

Links:

Volltext

Themen:

Journal Article
Research Support, Non-U.S. Gov't

Anmerkungen:

Date Completed 05.02.2021

Date Revised 05.02.2021

published: Print-Electronic

Citation Status PubMed-not-MEDLINE

doi:

10.1021/jacs.0c09080

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM316334774