1393834-80-4Relevant academic research and scientific papers
An effective and versatile strategy for the synthesis of structurally diverse heteroarylsilanesviaIr(iii)-catalyzed C-H silylation
Chen, Qi-Long,Dai, Kun-Long,Lu, Ka,Peng, Meng,Tu, Yong-Qiang,Yan, Zhi-Bo,Zhang, Fu-Min,Zhang, Xiao-Ming
, p. 9748 - 9753 (2021/07/28)
A versatile silylation of heteroaryl C-H bonds is accomplished under the catalysis of a well-defined spirocyclic NHC Ir(iii) complex (SNIr), generating a variety of heteroarylsilanes. A significant advantage of this catalytic system is that multiple types of intermolecular C-H silylation can be achieved using one catalytic system at α, β, γ, or δ positions of heteroatoms with excellent regioselectivities. Mechanistic experiments and DFT calculations indicate that the polycyclic ligand of SNIr can form an isolable cyclometalated intermediate, which leaves a phenyl dentate free and provides a hemi-open space for activating substrates. In general, favorable silylations occur at γ or δ positions of chelating heteroatoms, forming 5- or 6-membered C-Ir-N cyclic intermediates. If such an activation mode is prohibited sterically, silylations would take place at the α or β positions. The mechanistic studies would be helpful for further explaining the reactivity of the SNIr system.
Steric effects compete with aryne distortion to control regioselectivities of nucleophilic additions to 3-silylarynes
Bronner, Sarah M.,MacKey, Joel L.,Houk,Garg, Neil K.
, p. 13966 - 13969 (2012/10/29)
We report an experimental and computational study of 3-silylarynes. The addition of nucleophiles yield ortho-substituted products as a result of aryne distortion, but meta-substituted products form predominately when the nucleophile is large. Computations correctly predict the preferred site of attack observed in both nucleophilic addition and cycloaddition experiments. Nucleophilic additions to 3-tert-butylbenzyne, which is not significantly distorted, give meta-substituted products.
