Palladium-catalyzed -borylation of aryl halides, well-known as Miyaura borylation, is one of the reliable synthetic methods for organoborons. This reaction involves base-mediated nucleophilic activation of diboron that enables transmetalation of an aryl(halo)palladium(II) intermediate with a diboron. As an alternative, herein, we have established Lewis acid-mediated conditions for borylating (pseudo)haloarenes that require no external base. The electrophilic activation of the aryl(halo)palladium(II) intermediate via dehalogenation with Lewis acidic zinc complexes promotes the borylation.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1021/acs.orglett.3c03531 | DOI Listing |
Org Lett
December 2024
School of Chemical Science and Engineering, Shanghai Key Laboratory of Chemical Assessment and Sustainability, Tongji University, Shanghai 200092, People's Republic of China.
Org Lett
December 2024
Department of Chemistry, The University of Texas at Austin, 100 East 24th Street, Austin, Texas 78712, United States.
Herein, we report the palladium-catalyzed borylation of aryl halides (iodides or bromides) under base-free conditions utilizing a commercially available Lewis acidic mediator, Zn(OTf). Under these conditions, an array of electronically and functional-group-diverse aryl iodides and bromides undergo borylation to afford the corresponding aryl boronic esters in ≤82% isolated yields. Mechanistic investigations are consistent with Zn(OTf) enabling transmetalation between a cationic Pd(II)-Ar intermediate and Bpin via halide abstraction.
View Article and Find Full Text PDFBeilstein J Org Chem
November 2024
School of Chemistry, Chair of Organic Chemistry, Trinity Biomedical Sciences Institute, 152-160 Pearse Street, Trinity College Dublin, The University of Dublin, Dublin, D02 R590, Ireland.
Unlike their planar counterparts, classic synthetic protocols for C-C bond forming reactions on nonplanar porphyrins are underdeveloped. The development of C-C bond forming reactions on nonplanar porphyrins is critical in advancing this field of study for more complex porphyrin architectures, which could be used in supramolecular assemblies, catalysis, or sensing. In this work a library of arm-extended dodecasubstituted porphyrins was synthesized through the optimization of the classic Suzuki-Miyaura coupling of peripheral haloaryl substituents with a range of boronic acids.
View Article and Find Full Text PDFJ Org Chem
May 2024
Institute of Chemistry of Organometallic Compounds (CNR-ICCOM), 50019 Sesto Fiorentino, Italy.
We report an efficient procedure to carry out palladium-catalyzed Miyaura borylation reactions of (hetero)aromatic halides and triflates in choline chloride (ChCl)-based deep eutectic solvents (DESs). The procedure employs bis(pinacolato)diboron as a boron source and a catalyst prepared in situ from readily available Pd(dba) and the phosphine ligand XPhos. Reactions proceed well in different ChCl-based DESs, among which the best results were provided by environmentally friendly and biodegradable mixtures with glycerol and glucose.
View Article and Find Full Text PDFAdv Sci (Weinh)
June 2024
State Key Laboratory of Natural Medicines (SKLNM) and Department of Medicinal Chemistry, School of Pharmacy, China Pharmaceutical University, Nanjing, 210009, P. R. China.
Palladium-catalyzed Suzuki-Miyaura (SM) coupling is a valuable method for forming C─C bonds, including those between aryl moieties. However, achieving atroposelective synthesis of axially chiral styrenes via SM coupling remains challenging. In this study, a palladium-catalyzed atroposelective Suzuki-Miyaura coupling between gem-diborylalkenes and aryl halides is presented.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!