Iridium-catalyzed C–H borylation of quinolines and unsymmetrical 1,2-disubstituted benzenes: insights into steric and electronic effects on selectivity

@article{Tajuddin2012IridiumcatalyzedCB,
  title={Iridium-catalyzed C–H borylation of quinolines and unsymmetrical 1,2-disubstituted benzenes: insights into steric and electronic effects on selectivity},
  author={Hazmi Tajuddin and Peter Harrisson and Bianca Bitterlich and Jonathan C. Collings and Neil Sim and Andrei S. Batsanov and Man Sing Cheung and Soichiro Kawamorita and Aoife C. Maxwell and Lena Shukla and James Alan Morris and Zhenyang Lin and Todd B. Marder and Patrick G. Steel},
  journal={Chemical Science},
  year={2012},
  volume={3},
  pages={3505-3515}
}
Borylation of quinolines provides an attractive method for the late-stage functionalization of this important heterocycle. The regiochemistry of this reaction is dominated by steric factors but, by undertaking reactions at room temperature, an underlying electronic selectivity becomes apparent, as exemplified by the comparative reactions of 7-halo-2-methylquinoline and 2,7-dimethylquinoline which afford variable amounts of the 5- and 4-borylated products. Similar electronic selectivities are… 
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118 Citations

118 Citations

Metal-Free Borylation of Heteroarenes Using Ambiphilic Aminoboranes: On the Importance of Sterics in Frustrated Lewis Pair C-H Bond Activation.

Two novel frustrated Lewis pair aminoboranes were synthesized, and their structural features were elucidated both in solution and in the solid state, and it was shown that 2 and 3 are more active catalysts for the borylation of heteroarenes than the bulkier analogue 1.

Iridium-catalyzed C-H borylation of heteroarenes: scope, regioselectivity, application to late-stage functionalization, and mechanism.

One-pot functionalizations are reported of the hetero Daryl boronate esters formed in situ, demonstrating the usefulness of the reported methodology for the synthesis of complex heteroaryl structures.

Mechanistic Investigation of Iridium-Catalyzed C–H Borylation of Methyl Benzoate: Ligand Effects in Regioselectivity and Activity

The Ir-catalyzed C–H borylation of methyl benzoate has been studied with DFT methodology in order to understand the experimentally observed ligand-induced regioselectivity and activity when different…

para-C-H Borylation of Benzene Derivatives by a Bulky Iridium Catalyst.

The present [Ir(cod)OH]2/Xyl-MeO-BIPHEP catalyst represents a unique, sterically controlled, para-selective, aromatic C-H borylation system that should find use in streamlined, predictable chemical synthesis and in the rapid discovery and optimization of pharmaceuticals and materials.

The directing group wins over acidity: kinetically controlled regioselective lithiation for functionalization of 2-(2,4-dihalophenyl)-1,3-dithiane derivatives.

Computer calculated pKa values of the available reactive site protons and the experimental results suggest that the regioselective lithiation in 2-(2,4-dihalophenyl)-1,3-dithiane derivatives is not governed by thermodynamic acidity but exclusively dictated by the kinetic removal of protons due to cooperative coordination (complex induced proximity effect, CIPE).

Theoretical investigations of the Ir-catalyzed direct borylation of B(3,6)–H of o-carborane: the actual catalyst, mechanism, and origin of regioselectivity

The very recent success of Xie et al. (Nat. Commun., 2017, 8, 14827) in achieving the Ir-catalyzed direct borylation of the cage B(3,6)–H of o-carboranes with excellent yield and regioselectivity…

Iridium-catalyzed C-H borylation of pyridines.

The iridium-catalysed C-H borylation is a valuable and attractive method for the preparation of aryl and heteroaryl boronates but can be challenged by low reactivity and propensity for rapid protodeborylation, particularly for a bor onate ester ortho to the azinyl nitrogen.

Flexible Reaction Pocket on Bulky Diphosphine–Ir Complex Controls Regioselectivity in para-Selective C–H Borylation of Arenes

We used DFT calculations to elucidate the mechanism and source of regioselectivity for Ir-catalyzed para-selective C–H borylation with the bulky Xyl-MeO-BIPHEP diphosphine ligand (L1). We found that…

Rhodium-Catalyzed Intermolecular C–H Silylation of Arenes with High Steric Regiocontrol

A catalytic intermolecular C–H silylation of unactivated arenes that manifests very high regioselectivity through steric effects of substituents meta to a potential site of reactivity is reported.

Late-Stage Functionalization of 1,2-Dihydro-1,2-azaborines via Regioselective Iridium-Catalyzed C-H Borylation: The Development of a New N,N-Bidentate Ligand Scaffold.

The 6-[pyrid-2-yl]-B-Me-1,2-azaborine ligand has been demonstrated to form an emissive coordination complex with dimesitylboron that exhibits bathochromically shifted absorption and emission maxima and a higher photoluminescence quantum yield compared to its carbonaceous analogue.
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