Reactions of Al‐N Based Active Lewis Pairs with Ketones and 1,2‐Diketones: Insertion into Al‐N Bonds, C‐C and C‐N Bond Formation and a Tricyclic Saturated Tetraaza Compound

Abstract

The monomeric aluminum hydrazide iBu 2 Al-N(C 10 H 15)(NC 5 H 10) (1) features a strained AlN 2 ring and is an efficient active Lewis pair. It reacted with 2,3-diphenyl-2-cyclopropen-1-one by insertion of the C=O group into an Al-N bond, cleavage of the C 3 ring and formation of an AlOC 3 heterocycle (2). Diacetyl, Me(O)C-C(O)Me, and 1 afforded by insertion of keto groups into both Al-N bonds a heterocyclic α-keto-hemihydrazinal coordinated to aluminum (3). 3 contains fused AlO 2 C 2 and C 2 N 2 heterocycles. In an unexpected reaction,

Activation of Molecular Hydrogen by Inter‐ and Intramolecular Al−N Lewis Pairs

“…[5] In contrast to these FLPs, the AlÀ N systems garnered far less attention. Such studies were pursued, e. g. by Uhl and coworkers, [6] and rare examples for reactions with chalcogendouble bonds (CO 2 , [7] ketones, [8] isocyanates [9] ), dehydrocoupling, [10] acryl and lactone polymerisation have been reported. [11] Noteworthy, there are very few reports on hydrogenation reactions using AlÀ N compounds: At first, the catalytic hydrogenation of imines with H 2 in the presence of HAl i Bu 2 ( i Bu = isobutyl) should be mentioned.…”

Reactions of Mesityl Azide with Ferrocene‐Based N‐Heterocyclic Germylenes, Stannylenes and Plumbylenes, Including PPh2‐Functionalised Congeners

“…Consequently, plumbylene 12 exhibits a reduced frustration in comparison to 5 and thus belongs to the so-called active Lewis pairs (ALPs), which can show FLP-like behaviour due to the weakness of their coordinative bond. [57] Investigations addressing the activation of fundamentally important small molecules with 12 and closely related ALPs are underway in our laboratory. In addition, our study has demonstrated the ability of the unfunctionalised Nheterocyclic germylene 17 and its donor-functionalised relatives 14 and 23 to act as ligands for copper(I), thus underlining the potential of such ferrocene-based, and hence redox-functionalised, N-heterocyclic germylenes in coordination chemistry.…”

“…This may be ascribed to the fact that the P atom of 12 , in contrast to that of 5 , is engaged in an intramolecular coordinative bond to the Pb atom. Consequently, plumbylene 12 exhibits a reduced frustration in comparison to 5 and thus belongs to the so‐called active Lewis pairs (ALPs), which can show FLP‐like behaviour due to the weakness of their coordinative bond [57] . Investigations addressing the activation of fundamentally important small molecules with 12 and closely related ALPs are underway in our laboratory.…”

Transfer of an Aluminium Atom: An Avenue to Aluminium Heterocycles

“…This may enable transfer of the Al-heterocycles. [104][105][106] To this end, we initially treated 2 and 3 with various anionic nucleophiles including t BuOK, potassium bis(trimethylsilyl)amide (KHMDS), and PhLi. These reactions resulted in a complicated mixture and only potassium or lithium carbazolide could be identified.…”