Chen, Yan-Qiao published the artcileOvercoming the Limitations of γ- and δ-C-H Arylation of Amines through Ligand Development, Safety of 3-Bromo-6-iodo-imidazo[1,2-a]pyridine, the publication is Journal of the American Chemical Society (2018), 140(51), 17884-17894, database is CAplus and MEDLINE.
L,X-Type transient directing groups (TDGs) based on a reversible imine linkage have emerged as broadly useful tools for C-H activation of ketones and free amines. However, competitive binding interactions among multiple reaction components (TDG itself, substrate, and substrate-TDG adduct) with the palladium catalyst often lead to the formation of multiple unreactive complexes, rendering ligand development extremely challenging. Herein, we report the finding of versatile 2-pyridone ligands that addresses these problems and significantly improves the γ-methylene arylation of alkyl amines, extending the coupling partners to a wide range of medicinally important heteroaryl iodides and even previously unreactive heteroaryl bromides. The combination of an appropriate transient directing group and pyridone ligand has also enabled the δ-arylation of alkyl amines. Notably, our transient directing group design reveals the importance of matching the size of the Pd-chelation with different transient directing groups and the size of palladacycles generated from γ- and δ-C-H bonds: TDGs that coordinate with Pd(II) to form a six-membered chelate are selective toward γ-C-H bonds, whereas TDGs that coordinate with Pd(II) via a five-membered chelate tend to activate δ-C-H bonds. These findings provide an avenue for developing protecting group free and selective C-H functionalization using the transient directing group strategy.
Journal of the American Chemical Society published new progress about 1146615-52-2. 1146615-52-2 belongs to iodides-buliding-blocks, auxiliary class Other Aromatic Heterocyclic,Bromide,Iodide, name is 3-Bromo-6-iodo-imidazo[1,2-a]pyridine, and the molecular formula is C7H4BrIN2, Safety of 3-Bromo-6-iodo-imidazo[1,2-a]pyridine.
Referemce:
https://en.wikipedia.org/wiki/Iodide,
Iodide – an overview | ScienceDirect Topics – ScienceDirect.com