with somewhat reduced ionicity. Despite this, reactions of these types of borylimides with C-H or C≡C bonds are all more exothermic and more strongly activating than for the corresponding arylimides. DFT calculations on model systems of differing steric bulk unpicked the underlying thermodynamic factors controlling the reactions of 25 and its reaction partners, and a detailed comparison was made with
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金属
硼酰亚胺络合物的合成、机械和理论研究,(NacNacNMe2)ScNB(NAr'CH)2} (25, Ar' = 2,6-C6H3iPr2, NacNacNMe2 = Ar 'NC(Me)CHC(Me)N NMe2)。甲基
硼酰胺 (NacNacNMe2)Sc(Me)NHB(NAr'CH)2} (18) 的热解通过决定速率的一级
甲烷消除 (KIE ≈ 8.7) 生成瞬态
酰亚胺 25。在没有外部底物的情况下,25 与 NacNacNMe2
配体的甲基发生可逆的环
金属化反应(sp3 CH 键加成到 Sc=Nimide)形成 MeC(NC6H3iPrCH(Me)
CH2)CHC(Me)N NMe2}ScNHB (NAr'CH)2} (21)。在
吡啶或
DMAP 存在下,发生可逆的 sp2 CH 键活化,形成正
金属化配合物 (NacNacNMe2)S