Tricyclic Sulfoxide-Alkene Hybrid Ligands for Chiral Rh(I) Complexes: The "matched" Diastereomer Catalyzes Asymmetric C-C Bond Formations

Nikol A, Zhang Z, Chelouan A, Falivene L, Cavallo L, Herrera A, Heinemann FW, Escalona A, Frieß S, Grasruck A, Dorta R (2020)

Publication Type: Journal article

Publication year: 2020

Journal

Organometallics American Chemical Society

DOI: 10.1021/acs.organomet.0c00094

Abstract

Deprotonation of phenyldibenzo[b,f]tropylidene (8) with LDA/t-BuOK followed by quenching with either diastereomer of inexpensive glucose-based t-Bu-sulfinate (R)- or (S)-11 affords a sulfoxide-alkene hybrid ligand as the diastereomeric pairs (SS,SC)-9/(SS,RC)-10 and (RS,RC)-9/(RS,SC)-10, respectively, which via chromatographic/recrystallization may be separated into the four isomers. The optically pure diastereomeric ligands (SS,SC)-9 and (SS,RC)-10 react with [RhCl(coe)2]2 to form the dinuclear complexes (RS,SC)-11 and (RS,RC)-12, respectively, in which the bidentate ligands coordinate the metal centers through the sulfur and alkene donor functions. These complexes catalyze the conjugate addition of arylboronic acids to cyclic Michael acceptors with enantioselectivities of up to 99% ee. DFT calculations show the preponderant influence of planar chirality of the ligand alkene function. The enantioselectivity switch observed between (RS,SC)-11 and (RS,RC)-12 is explained by the inverted cis-trans coordinations of the substrate molecules in catalytic steps.

Authors with CRIS profile

Ahmed Chelouan Lehrstuhl für Anorganische und Allgemeine Chemie Alberto Cesar Herrera Professur für Anorganische Chemie Frank Wilhelm Heinemann Lehrstuhl für Anorganische und Allgemeine Chemie Ana Melissa Escalona Bauza Lehrstuhl für Anorganische und Metallorganische Chemie Sibylle Frieß Lehrstuhl für Anorganische und Allgemeine Chemie Alexander Grasruck Professur für Anorganische Chemie Romano Dorta Professur für Anorganische Chemie

Involved external institutions

King Abdullah University of Science and Technology (KAUST) / جامعة الملك عبد الله للعلوم و التقنية SA Saudi Arabia (SA)

How to cite

APA:

Nikol, A., Zhang, Z., Chelouan, A., Falivene, L., Cavallo, L., Herrera, A.,... Dorta, R. (2020). Tricyclic Sulfoxide-Alkene Hybrid Ligands for Chiral Rh(I) Complexes: The "matched" Diastereomer Catalyzes Asymmetric C-C Bond Formations. Organometallics. https://doi.org/10.1021/acs.organomet.0c00094

MLA:

Nikol, Alexander, et al. "Tricyclic Sulfoxide-Alkene Hybrid Ligands for Chiral Rh(I) Complexes: The "matched" Diastereomer Catalyzes Asymmetric C-C Bond Formations." Organometallics (2020).

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