Jump to main content
Jump to site search

Issue 11, 2017
Previous Article Next Article

“Masked” Lewis-acidity of an aluminum α-phosphinoamide complex

Author affiliations


The reaction of Ph2P(DIPP)NH with AlMe3 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 Ph2P(DIPP)NAlMe2·THF. Efforts to use [Ph2P(DIPP)NAlMe2]2 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 [Ph2P(DIPP)NAlMe2]2 with CO2, however, gave an insertion in the N–Al bond and the dimeric product [Ph2P(DIPP)NCO2AlMe2]2 was isolated. The dimer [Ph2P(DIPP)NAlMe2]2 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-Ph2P-CH(CH2SMe)CH2]AlMe2 and [(DIPP)N-Ph2P-CH(C4H9)CH2]AlMe2.

Graphical abstract: “Masked” Lewis-acidity of an aluminum α-phosphinoamide complex

Back to tab navigation

Supplementary files

Publication details

The article was received on 26 Jan 2017, accepted on 13 Feb 2017 and first published on 28 Feb 2017

Article type: Paper
DOI: 10.1039/C7DT00318H
Citation: Dalton Trans., 2017,46, 3601-3610

  •   Request permissions

    “Masked” Lewis-acidity of an aluminum α-phosphinoamide complex

    H. S. Zijlstra, J. Pahl, J. Penafiel and S. Harder, Dalton Trans., 2017, 46, 3601
    DOI: 10.1039/C7DT00318H

Search articles by author