tertiary carbon in this system. The mechanism ia an alkane path provides an insight into the closely related photochemical and catalytic thermal alkane dehydrogenation processes mediated by IrH2(O2CCF3)(PAr3)2; the thermal route requires tBuCHCH2 as the hydrogen acceptor. These two alkane reactions are intimately related mechanistically to the isotope exchange because they are proposed to have the same intermediates
要了解使用IrH 2(O 2 CCF 3)(PAr 3)2(Ar = p -FC 6 H 4)进行光
化学和热
烷烃活化,烯烃和IrD 2(O 2 CCF 3)(PAr)之间的H / D同位素加扰3)研究了2。无法对实验数据进行唯一的解释,因此在Ir(H)2(O 2 CCF 3)(PH 3)2(C 2 H 4)中交换过程的DFT(B3PW91)计算)以区分实验允许的可能性。在H / D加扰的几种可能机制中,强烈推荐一种机制,因此在此提出。它涉及烯烃的插入以得到烷基氢化该还原消除导致包含一个η的过渡状态3结合的
烷烃。这种实现1,1'双子H / D交换的过渡态的能量明显低于作为次要最小值的二氢卡宾,从而消除了卡宾机制。
烷烃(“粘性
烷烃”)与Ir(O 2 CCF 3)(PH 3)2片段的结合能(BDE)出乎意料的大(BDE = 11.9 kcal mol -1)在该过渡态中部分归因于存在弱的σ-和π-供体(CF