278608-73-4Relevant articles and documents
Reactions of an Aluminum(I) Reagent with 1,2-, 1,3-, and 1,5-Dienes: Dearomatization, Reversibility, and a Pericyclic Mechanism
Bakewell, Clare,Crimmin, Mark R.,Gar?on, Martí,Kong, Richard Y.,O'Hare, Louisa,White, Andrew J. P.
, (2020)
Addition of the aluminum(I) reagent [{(ArNCMe)2CH}Al] (Ar = 2,6-di-iso-propylphenyl) to a series of cyclic and acyclic 1,2-, 1,3-, and 1,5-dienes is reported. In the case of 1,3-dienes, the reaction occurs by a pericyclic reaction mechanism, specifically a cheletropic cycloaddition, to form aluminocyclopentene-containing products. This mechanism has been examined by stereochemical experiments and DFT calculations. The stereochemical experiments show that the (4 + 1) cycloaddition follows a suprafacial topology, while calculations support a concerted albeit asynchronous pathway in which the transition state demonstrates aromatic character. Remarkably, the substrate scope of the (4 + 1) cycloaddition includes styene, 1,1-diphenylethylene, and anthracene. In these cases, the diene motif is either in part, or entirely, contained within an aromatic ring and reactions occur with dearomatisation of the substrate and can be reversible. In the case of 1,2-cyclononadiene or 1,5-cyclooctadiene, complementary reactivity is observed; the orthogonal nature of the Ca? C ?-bonds (1,2-diene) and the homoconjugated system (1,5-diene) both disfavor a (4 + 1) cycloaddition. Rather, reaction pathways are determined by an initial (2 + 1) cycloaddition to form an aluminocyclopropane intermediate which can in turn undergo insertion of a further Ca? C ?-bond, leading to complex organometallic products that incorporate fused hydrocarbon rings.
Reactions of Fluoroalkenes with an Aluminium(I) Complex
Bakewell, Clare,White, Andrew J. P.,Crimmin, Mark R.
supporting information, p. 6638 - 6642 (2018/05/05)
A series of industrially relevant fluoroalkenes react with a monomeric AlI complex. These reactions break strong sp2 and sp3 C?F bonds, and result in the formation of a diverse array of organoaluminium compounds. Mechanistic studies show that two mechanisms are likely in operation: 1) direct oxidative addition of the C?F bond to AlI occurs with retention of alkene stereochemistry, and 2) stepwise formation and decomposition of a metallocyclopropane intermediate occurs with inversion of alkene stereochemistry. As part of this mechanistic analysis, we have isolated the first aluminium metallocyclopropane complex from oxidative addition of an alkene to AlI. Remarkably this reaction is reversible and reductive elimination of the alkene occurs at higher temperature reforming AlI. Furthermore, in selected cases the organoaluminium products are susceptible toward β-fluoride elimination to yield a double C?F activation pathway.
Unprecedented reactivity of an aluminium hydride complex with ArNH 2BH3: Nucleophilic substitution versus deprotonation
Harder, Sjoerd,Spielmann, Jan
, p. 11945 - 11947 (2011/12/01)
Reaction of DIPPnacnacAlH2 with DIPPNH2BH3 did not give the anticipated deprotonation but nucleophilic substitution at B was observed instead. The product DIPPnacnacAl(BH4)2 was isolated and structura
