Reduction vs. Addition: The Reaction of an Aluminyl Anion with 1,3,5,7‐Cyclooctatetraene

Abstract

The potassium aluminyl complex K[Al(NON Ar )] (NON = NON Ar = [O(SiMe 2 NAr) 2 ] 2À ,A r = 2,6-iPr 2 C 6 H 3 ) reacts with 1,3,5,7-cyclooctatetraene (COT) to give K[Al-(NON Ar )(COT)].The COT-ligand is present in the asymmetric unit as ap lanar m 2 -h 2 :h 8 -bridge between Al and K, with additional K···p-aryl interactions to neighboring molecules that generate ah elical chain. DFT calculations indicate significant aromatic character,c onsistent with reduction to [COT] 2À . Addition of 18-crown-6c auses ar earrangement of the C 8carbocycle to form the isomeric 9-aluminabicyclo[4.2.1]nona-2,4,7-triene anion.

Cycloaddition of Dialkylalumanyl Anion toward Unsaturated Hydrocarbons in (1+2) and (1+4) Modes

“…Compounds 2 and 3 are the first examples of anionic aluminanorbornadiene derivatives. Two newly formed Al−C(bridgehead) bonds of 2 and 3 [ 2 : 2.1118(15), 2.1087(15) Å; 3 : 2.1125(12), 2.1154(15) Å] are longer than those of the previously reported Al‐incorporated bicyclic compounds ( L , J , K ), reflecting the steric repulsion between four trimethylsilyl substituents and benzoannulated moiety in 2 and 3 . As a result, the C‐Al‐C angles in 2 and 3 [ 2 : 75.10(6)°; 3 : 75.21(6)°] are slightly smaller than those of reference compounds.…”

“…The NacNac‐stabilized Al I species B underwent (1+2) cycloaddition with alkynes and alkenes to form Al‐containing three‐membered ring species G . The diamino–Al anion D cyclized with cyclooctatetraene to give H via (1+2) cycloaddition . Similarly, the monomeric form of oxygen‐stabilized Al anion F reacted with ethylene to form (1+2) cycloadduct I .…”

“…On the other hand, B also reacted with a benzene complex of [NacNac‐Ca] + to give an alumanorbornadiene product J . The anionic bicyclic compound H rearranged to the (1+4) product K upon addition of [18]crown‐6 . Thus, compounds B and D are examples of Al I compound, which exhibit reactivity for two different modes of cycloaddition reaction.…”

An Alumanylyttrium Complex with an Absorption due to a Transition from the Al−Y Bond to an Unoccupied d‐Orbital

“…In contrast, three types of anionic and nucleophilic aluminum species have been reported recently and used as an Al I species in a low oxidation state . It should be noted here that the base‐stabilized aluminum anion was used for the synthesis of a base‐stabilized alumanylgold complex (see class‐(iii) complexes above) through a nucleophilic substitution at the gold center .…”

Aluminium‐Mediated Carbon Dioxide Reduction by an Isolated Monoalumoxane Anion

“…Notwithstanding this limitation, pioneering work has shown that aneutral dialumene activates CO 2 to give the aluminumcarbonate (VI)a nd -carbonyl (VII)c omplexes. Recent advances in group 13 chemistry have led to the development of new nucleophilic sources of aluminum [17] and indium. [16] Theu tilization of aluminum in this area is particularly attractive due to its low cost and high terrestrial abundance.…”