The use of ligands to tune the reactivity and selectivity of transition metal catalysts for C(sp(3))-H bond functionalization is a central challenge in synthetic organic chemistry. Herein, we report a rare example of catalyst-controlled C(sp(3))-H arylation using pyridine and quinoline derivatives: The former promotes exclusive monoarylation, whereas the latter activates the catalyst further to achieve diarylation. Successive application of these ligands enables the sequential diarylation of a methyl group in an alanine derivative with two different aryl iodides, affording a wide range of β-Ar-β-Ar'-α-amino acids with excellent levels of diastereoselectivity (diastereomeric ratio > 20:1). Both configurations of the β-chiral center can be accessed by choosing the order in which the aryl groups are installed. The use of a quinoline derivative as a ligand also enables C(sp(3))-H olefination of a protected alanine.
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http://dx.doi.org/10.1126/science.1249198 | DOI Listing |
Proc Natl Acad Sci U S A
January 2025
School of Biomolecular Science and Engineering, Vidyasirimedhi Institute of Science and Technology (VISTEC), Rayong 10120, Thailand.
A single-component flavin-dependent halogenase, AetF, has emerged as an attractive biocatalyst for catalyzing halogenation. However, its flavin chemistry remains unexplored and cannot be predicted due to its uniqueness in sequence and structure compared to other flavin-dependent monooxygenases. Here, we investigated the flavin reactions of AetF using transient kinetics.
View Article and Find Full Text PDFOrg Lett
January 2025
School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan.
The C2- or C3-selective direct C-H arylation of nonsubstituted 1-pyrrole with aryl chlorides/nonaflates was achieved using catalysts derived from palladium and appropriate phosphine ligands. The site selectivity of the arylation can be switched by changing the ligands, and the C3-selective arylation of nonsubstituted 1-pyrrole was realized for the first time. BuOLi played an important role in suppressing N-arylation and accelerating C2- or C3-arylation.
View Article and Find Full Text PDFJ Org Chem
January 2025
Department of Chemistry and Biochemistry, Loyola University Chicago, Chicago, Illinois 60660, United States.
Chemistry
December 2024
Shanghai Key Laboratory of Green Chemistry and Chemical Processes, State Key Laboratory of Petroleum Molecular & Process Engineering, School of Chemistry and Molecular Engineering, East China Normal University, Shanghai, 200062, China.
Pd-catalyzed alkoxycarbonylation of internal alkynes provides a straightforward access to α,β-disubstituted acrylic esters. Compared with the well-established regioselective alkoxycarbonylation of terminal alkynes, the regioselective hydrocarboxylation of non-functionalized unsymmetric internal alkynes was more challenging owing to the delicate differences of properties between the two substituents. Herein, by using either monophosphine ligand based on 2,3-dihydrobenzo[d][1,3]oxaphosphole motif or bidentate ligand Ph-Phox, the regioselective alkoxycarbonylations of aryl-aryl, aryl-alkyl and alkyl-alkyl disubstituted alkynes were achieved, giving a diversity of trisubstituted α,β-unsaturated carboxylic esters with moderate to excellent yields and high regioselectivity.
View Article and Find Full Text PDFChem Sci
December 2024
Leibniz-Institut für Katalyse e.V. Albert-Einstein-Straße 29a 18059 Rostock Germany
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