Browsing by Author "Yu, Ming-Shiuan"

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Mechanistic Study of a Switch in the Regioselectivity of Hydroheteroarylation of Styrene Catalyzed by Bimetallic Ni-Al through C-H Activation
(2014-06-23)
Chen, Wen-Ching
;
Lai, Ying-Chieh
;
Shih, Wei-Chun
;
Yu, Ming-Shiuan
;
Yap, Glenn P. A.
We previously reported a highly efficient protocol for bimetallic Ni-Al-catalyzed hydroheteroarylation of styrene with benzimidazole based on C-H bond activation. We have now delineated the mechanism of this process, providing a rationale for an observed switch in regioselectivity in the presence of the Lewis acid, AlMe3. The present mechanistic study gives insights for the rational development of catalysts that exhibit required linear/branched selectivity.
Nickel-catalysed para-CH activation of pyridine with switchable regioselective hydroheteroarylation of allylarenes
(2015-01-01)
Lee, Wei-Chih
;
Chen, Chien-Hung
;
Liu, Cheng-Yuan
;
Yu, Ming-Shiuan
;
Lin, Yung-Huei
para-CH activation of pyridine with allylbenzene is described by Ni/Al cooperative catalysis in combination with a bulkier NHC ligand and a Lewis acid, leading to linear hydroheteroarylation products. Interestingly, the branch selectivity can be achieved by using the combination of a less sterically hindered amino-NHC ligand and AlMe3 through tandem reaction of facile alkene isomerization followed by a slow CH bond activation process.
Selective C(8)-H Activation of Imidazopyridines Mediated by Cooperative Nickel-Aluminum Catalysis
(2016-09-01)
Liu, Cheng-Yuan
;
Chen, Ying-Ho
;
Chen, Chih-Hao
;
Yu, Ming-Shiuan
;
Tsai, Fu-Yu
A catalytic paradigm is described featuring a synergistic interaction between nickel, aluminum and different ligands to impart a rather remote C-H alkenylation of imidazo[1,5-a] pyridines at the C-8 position without the necessity of installing a directing group. The scope of the direct C-H activation reactions of various 5-aryl- and 3-arylimidazopyridines is established using different sterically hindered alkynes.