Zijlstra Harmen S, Pahl Jürgen, Penafiel Johanne, Harder Sjoerd
Inorganic and Organometallic Chemistry, University of Erlangen-Nürnberg, Egerlandstrasse 1, 91058 Erlangen, Germany.
Dalton Trans. 2017 Mar 14;46(11):3601-3610. doi: 10.1039/c7dt00318h.
The reaction of PhP(DIPP)NH with AlMe cleanly gives an aluminum amide complex that crystallizes as a centrosymmetric dimer with a six-membered Al-N-P-Al-N-P ring. In aromatic solvents the dimer remains intact but the Al-P bond is readily broken upon addition of THF to form PhP(DIPP)NAlMe·THF. Efforts to use [PhP(DIPP)NAlMe] as a "masked" Lewis acidic activator for olefin polymerization catalysts were unsuccessful but the complex showed a Frustrated Lewis pair reactivity instead. The P/Al complex reacts with isocyanates to give the C[double bond, length as m-dash]O inserted product that crystallizes as a five-membered ring system Al-O-C(NR)-P-N. The reaction of [PhP(DIPP)NAlMe] with CO, however, gave an insertion in the N-Al bond and the dimeric product [PhP(DIPP)NCOAlMe] was isolated. The dimer [PhP(DIPP)NAlMe] is one of the few Al/P FLPs that can activate C[double bond, length as m-dash]C double bonds irreversibly. A reaction with allyl methyl sulfide and 1-hexene led to the clean formation of the structurally similar activated alkene products [(DIPP)N-PhP-CH(CHSMe)CH]AlMe and [(DIPP)N-PhP-CH(CH)CH]AlMe.
PhP(DIPP)NH 与 AlMe 反应可顺利生成一种铝酰胺配合物，该配合物结晶为具有六元 Al-N-P-Al-N-P 环的中心对称二聚体。在芳香族溶剂中，二聚体保持完整，但加入 THF 后，Al-P 键很容易断裂，形成 PhP(DIPP)NAlMe·THF。试图将 [PhP(DIPP)NAlMe] 用作烯烃聚合催化剂的 “掩蔽” 路易斯酸性活化剂未成功，但该配合物反而表现出受阻路易斯对反应活性。P/Al 配合物与异氰酸酯反应生成 C=O 插入产物，该产物结晶为五元环体系 Al-O-C(NR)-P-N。然而，[PhP(DIPP)NAlMe] 与 CO 反应时，N-Al 键发生插入反应，分离得到二聚产物 [PhP(DIPP)NCOAlMe]。二聚体 [PhP(DIPP)NAlMe] 是少数能够不可逆地活化 C=C 双键的 Al/P 受阻路易斯对之一。与烯丙基甲基硫醚和 1-己烯反应可顺利生成结构相似的活化烯烃产物 [(DIPP)N-PhP-CH(CHSMe)CH]AlMe 和 [(DIPP)N-PhP-CH(CH)CH]AlMe。
