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Scott NW, Ford MJ, Jeddi N, Eyles A, Simon L, Whitwood AC, Tanner T, Willans CE, Fairlamb IJS. A Dichotomy in Cross-Coupling Site Selectivity in a Dihalogenated Heteroarene: Influence of Mononuclear Pd, Pd Clusters, and Pd Nanoparticles-the Case for Exploiting Pd Catalyst Speciation. J Am Chem Soc 2021; 143:9682-9693. [PMID: 34152135 PMCID: PMC8297865 DOI: 10.1021/jacs.1c05294] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2021] [Indexed: 12/23/2022]
Abstract
Site-selective dihalogenated heteroarene cross-coupling with organometallic reagents usually occurs at the halogen proximal to the heteroatom, enabled by intrinsic relative electrophilicity, particularly in strongly polarized systems. An archetypical example is the Suzuki-Miyaura cross-coupling (SMCC) of 2,4-dibromopyridine with organoboron species, which typically exhibit C2-arylation site-selectivity using mononuclear Pd (pre)catalysts. Given that Pd speciation, particularly aggregation, is known to lead to the formation of catalytically competent multinuclear Pdn species, the influence of these species on cross-coupling site-selectivity remains largely unknown. Herein, we disclose that multinuclear Pd species, in the form of Pd3-type clusters and nanoparticles, switch arylation site-selectivity from C2 to C4, in 2,4-dibromopyridine cross-couplings with both organoboronic acids (SMCC reactions) and Grignard reagents (Kumada-type reactions). The Pd/ligand ratio and the presence of suitable stabilizing salts were found to be critically important in switching the site-selectivity. More generally, this study provides experimental evidence that aggregated Pd catalyst species not only are catalytically competent but also alter reaction outcomes through changes in product selectivity.
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Affiliation(s)
- Neil W.
J. Scott
- Department
of Chemistry, University of York, Heslington, York, North
Yorkshire YO10 5DD, United Kingdom
| | - Mark J. Ford
- Bayer
AG, Alfred-Nobel-Strasse
50, 40789 Monheim, Germany
| | - Neda Jeddi
- Department
of Chemistry, University of York, Heslington, York, North
Yorkshire YO10 5DD, United Kingdom
| | - Anthony Eyles
- Department
of Chemistry, University of York, Heslington, York, North
Yorkshire YO10 5DD, United Kingdom
| | - Lauriane Simon
- Department
of Chemistry, University of York, Heslington, York, North
Yorkshire YO10 5DD, United Kingdom
| | - Adrian C. Whitwood
- Department
of Chemistry, University of York, Heslington, York, North
Yorkshire YO10 5DD, United Kingdom
| | - Theo Tanner
- Department
of Chemistry, University of York, Heslington, York, North
Yorkshire YO10 5DD, United Kingdom
| | - Charlotte E. Willans
- School
of Chemistry, University of Leeds, Woodhouse Lane, Leeds LS2 9JT, United
Kingdom
| | - Ian J. S. Fairlamb
- Department
of Chemistry, University of York, Heslington, York, North
Yorkshire YO10 5DD, United Kingdom
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Zhao X, Chen H, Xing S, Yuan W, Wu L, Chen X, Zhan CG. Regioselective synthesis of 2- and 4-diarylpyridine ethers and their inhibitory activities against phosphodiesterase 4B. J Mol Struct 2019. [DOI: 10.1016/j.molstruc.2019.06.086] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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3
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Fowler JM, Britton E, Pask CM, Willans CE, Hardie MJ. Cyclotriveratrylene-tethered trinuclear palladium(ii)-NHC complexes; reversal of site selectivity in Suzuki-Miyaura reactions. Dalton Trans 2019; 48:14687-14695. [PMID: 31538177 DOI: 10.1039/c9dt03400e] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The trinuclear complexes [{PdI2(pyCl)}3(L1)] C1 and [{PdI2(pyCl)}3(L2)] C2, where pyCl = 3-chloropyridine, L1 = methyl(cyclotriguaiacylenyl)methylbenzimidazol-2-ylidene and L2 = benzyl(cyclotriguaiacylenyl)methylbenzimidazol-2-ylidene, each feature three palladium N-heterocyclic carbene (NHC) centres tethered onto a host-type cyclotriguaiacylene scaffold. Crystal structures of different solvates of complex C1 reveal different host-guest motifs including intra-cavity binding of dioxane guests concomitant with intramolecular halogen bonding interactions of C1. Mononuclear NHC analogues of C1 and C2, namely [PdI2(pyCl)(L3)] C3 and [PdI2(pyCl)(L4)] C4, where L3 = (3-chloropyridyl)-1-(2-methoxyphenyoxy)methyl-3-methylbenzimidazol-2-ylidene and L4 = (3-chloropyridyl)-1-(2-methoxyphenyoxy)methyl-3-benzylbenzimidazol-2-ylidene, were also synthesised and their crystal structures determined. Complexes C1-C4 are competent catalysts for Suzuki Miyaura cross-coupling, and interestingly exhibit a switch in the normal regioselectivity observed for reactions of 2,4-dibromopyridine with aryl boronic acids, usually C2-selective, yielding C4-arylated product preferentially over C2-arylated product.
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Affiliation(s)
- Jonathan M Fowler
- School of Chemistry, University of Leeds, Woodhouse Lane, Leeds LS2 9JT, UK.
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Rivera RP, Ehlers P, Ohlendorf L, Ponce MB, Rodríguez ET, Langer P. Synthesis of non-symmetrical alkynylpyridines by chemoselective Sonogashira cross-coupling reactions. Tetrahedron 2019. [DOI: 10.1016/j.tet.2019.130559] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Jo YI, Burke MD, Cheon CH. Modular Syntheses of Phenanthroindolizidine Natural Products. Org Lett 2019; 21:4201-4204. [DOI: 10.1021/acs.orglett.9b01397] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- Young-In Jo
- Department of Chemistry, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea
| | - Martin D. Burke
- Department of Chemistry and Carle Illinois College of Medicine, University of Illinois at Urbana−Champaign, 600 South Mathews Avenue, Urbana, Illinois 61801, United States
| | - Cheol-Hong Cheon
- Department of Chemistry, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea
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Gulevskaya AV, Shvydkova EA, Tonkoglazova DI. Synthesis and Characterization of Pyridine-, Pyrazine-, and Quinoxaline-Derived [4]Helicenes and S-Shaped Double [4]Helicenes. European J Org Chem 2018. [DOI: 10.1002/ejoc.201800613] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Affiliation(s)
- Anna V. Gulevskaya
- Department of Chemistry; Southern Federal University; Zorge str., 7 344090 Rostov-on-Don Russian Federation
| | - Ekaterina A. Shvydkova
- Department of Chemistry; Southern Federal University; Zorge str., 7 344090 Rostov-on-Don Russian Federation
| | - Daria I. Tonkoglazova
- Department of Chemistry; Southern Federal University; Zorge str., 7 344090 Rostov-on-Don Russian Federation
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