Tseng, Hsi ChingHsi ChingTsengChen, Po-HanPo-HanChenLiu, Yi HungYi HungLiuLi, Zhen HuaZhen HuaLiCHING-WEN CHIU2024-04-232024-04-232024-01-0102767333https://scholars.lib.ntu.edu.tw/handle/123456789/642013Compared to borenium ions, the synthetic application of its dicoordinate variant, borinium ion, remains much less explored due to the facile decomposition of borinium ions. Previously, we showed that [Cp*B-Mes]+ ([1]+) can be viewed as a masked borinium ion with great potential in catalysis. In this study, we further demonstrate that [1]+ serves as a precatalyst in catalytic cyanosilylation of ketones. When treated with TMSCN, [1]+ transforms into a TMSCN coordinated boronium ion [Cp*BMes(TMSCN)2]+ ([4]+), which is highly efficient in catalyzing cyanosilylation. However, such reagent-coordinated boronium ion cannot be accomplished in the absence of Cp* ligand. Experimental and computational investigations revealed that the Cp* ligand could mitigate the Lewis acidity of the putative borenium ion, [Cp*BMes(TMSCN)]+ ([5]+), via the coordination of Cp* to boron in a η2-coordination fashion. Such a bonding interaction significantly reduces the positive charge on the boron atom [5]+, preventing the decomposition of the critical intermediate.enjournal article10.1021/acs.organomet.4c000562-s2.0-85189032879https://api.elsevier.com/content/abstract/scopus_id/85189032879