Hexa-coordinated aluminum and gallium cations derived from indazole

An Investigation of the Symmetric and Asymmetric Cleavage Products in the System Aluminum Trihalide/1‐Butylimidazole

“…The molecular structures of [AlCl 3 (BuIm)] and [AlCl 2 (BuIm) 4 ]Cl ⋅ MeCN are shown in Figure . The Al−N and Al−Cl distances are in the range of the bond lengths in other complexes of the type [AlCl 3 (L)] and [AlCl 2 (L) 4 ] + . The Al−N distances are almost identical in [AlBr 3 (BuIm)] and [AlCl 3 (BuIm)].…”

“…Depending on their nature and the experimental conditions, the Lewis bases can induce symmetric or asymmetric cleavage of dimeric Al 2 X 6 , which results in the formation of neutral adducts or salts (Scheme ). Crystal structures of the neutral adducts [AlX 3 (L)], trans ‐[AlX 3 (L) 2 ], and mer ‐[AlX 3 (L) 3 ], as well as the cationic aluminum complexes [AlX 2 (L) 2 ] + , [AlX 2 (L) 4 ] + , [AlX(L) 5 ] 2+ , and [Al(L) 6 ] 3+[4, 21, 22] with monodentate N, O, S, and P ligands L are known.…”

Regioselective synthesis of 2H-indazoles through Ga/Al- and Al-mediated direct alkylation reactions of indazoles

“…Finally, the allylation reaction takes place in a normal fashion even in the case of an indazole substrate bearing an amino substituent ( Table 5, entry 4). 12 Therefore, reaction of indazole with the η1-allyl complex could go through the chelation or non-chelation pathway, which enables the kinetically controlled reaction that leads to 2-allyl 2H-indazole. The reaction of gallium (aluminium) metal and allyl bromide generates an allylgallium (allylaluminium) cation complex.…”

“…11 Moreover, it has been reported that indazole serves as a chelating ligand for aluminum and gallium cations through coordination utilizing its N-2 lone pair. 12 In a related effort, it has been shown that gallium and allyl bromide participate in nucleophilic substitution reactions in aqueous media, as is exemplified by C-3 allylation reactions of indoles. 13 These observations led us to propose a new method for the regioselective synthesis of 2-substituted 2H-indazoles that involves gallium-mediated N-2 allylation reactions with allyl bromide.…”

[GaX2(dmpe)2][GaX4] (X = Cl, Br, I): a synthetic, solid state, and computational study

“…Nevertheless, hypervalent environments involving five and six electron pairs around the p-block centre are observed for many p-block elements, including examples of complexes involving L-type ligands. The chemistry of aluminum and gallium are most developed in this context, [1][2][3][4][5] and the presence of a cationic charge naturally enhances the Lewis acidity of the acceptor site, which we have exploited to realize examples of phosphine and pyridine complexes of pnictogen centres (Group 15) and tetrael centres (Group 14). [6][7][8][9] While reports of solid state structures for phosphine complexes of gallium are relatively rare, 10 Levason et al revealed structural diversity for diphosphine complexes of gallium, 5 with the expectation that a four coordinate tetrahedral environment is favoured for gallium.…”