Arene C−H Activation at Aluminium(I): meta Selectivity Driven by the Electronics of S N Ar Chemistry
The reactivity of the electron-rich anionic Al(I) ('aluminyl') compound K 2 [(NON)Al] 2 (NON = 4,5-bis(2,6-diisopropylanilido)-2,7-di- tert -butyl-9,9-dimethylxanthene) towards mono- and disubstituted arenes is reported. C-H activation chemistry with n -butylbenzene gives exclusively the product of activation at the arene meta position. Mechanistically, this transformation proceeds in a single step via a concerted Meisenheimer-type transition state. Selectivity is therefore based on similar electronic factors to classical S N Ar chemistry, which implies the destabilization of transition states featuring electron-donating groups in either the ortho or the para positions. In the cases of tolu…
The Aluminyl Anion : A New Generation of Aluminium Nucleophile
Trivalent aluminium compounds are well known for their reactivity as Lewis acids/electrophiles, a feature that is exploited in many pharmaceutical, industrial and laboratory-based reactions. Recently, a series of isolable aluminium(I) anions ('aluminyls') have been reported, which offer an alternative to this textbook description: these reagents behave as aluminium nucleophiles. This minireview covers the synthesis, structure and reactivity of aluminyl species reported to date, together with their associated metal complexes. The frontier orbitals of each of these species have been investigated using a common methodology to allow for a like-for-like comparison of their electronic structure a…
Carbon monoxide activation by a molecular aluminium imide: C-O bond cleavage and C-C bond formation
Anionic molecular imide complexes of aluminium are accessible via a rational synthetic approach involving the reactions of organo azides with a potassium aluminyl reagent. In the case of K2 [(NON)Al(NDipp)]2 (NON=4,5-bis(2,6-diisopropylanilido)-2,7-di-tert-butyl-9,9-dimethyl-xanthene; Dipp=2,6-diisopropylphenyl) structural characterization by X-ray crystallography reveals a short Al-N distance, which is thought primarily to be due to the low coordinate nature of the nitrogen centre. The Al-N unit is highly polar, and capable of the activation of relatively inert chemical bonds, such as those found in dihydrogen and carbon monoxide. In the case of CO, uptake of two molecules of the substrate…
A nucleophilic gold complex.
Solid-state auride salts featuring the negatively charged Au– ion are known to be stable in the presence of alkali metal counterions. While such electron-rich species might be expected to be nucleophilic (in the same manner as I–, for example), their instability in solution means that this has not been verified experimentally. Here we report a two-coordinate gold complex (NON)AlAuPtBu3 (where NON is the chelating tridentate ligand 4,5-bis(2,6-diisopropylanilido)-2,7-di-tert-butyl-9,9-dimethylxanthene) that features a strongly polarized bond, Auδ––Alδ+. This is synthesized by reaction of the potassium aluminyl compound [K{Al(NON)}]2 with tBu3PAuI. Computational studies of the complex, includ…
Probing the Extremes of Covalency in M-Al bonds: Lithium and Zinc Aluminyl Compounds.
Synthetic routes to lithium, magnesium, and zinc aluminyl complexes are reported, allowing for the first structural characterization of an unsupported lithium-aluminium bond. Crystallographic and quantum-chemical studies are consistent with the presence of a highly polar Li-Al interaction, characterized by a low bond order and relatively little charge transfer from Al to Li. Comparison with magnesium and zinc aluminyl systems reveals changes to both the M-Al bond and the (NON)Al fragment (where NON=4,5-bis(2,6-diisopropylanilido)-2,7-di-tert-butyl-9,9-dimethylxanthene), consistent with a more covalent character, with the latter complex being shown to react with CO<sub>2</sub> vi…
Trapping and Reactivity of a Molecular Aluminium Oxide Ion
Aluminium oxides constitute an important class of inorganic compound that are widely exploited in the chemical industry as catalysts and catalyst supports. Due to the tendency for such systems to aggregate via Al‐O‐Al bridges, the synthesis of well‐defined, soluble, molecular models for these materials is challenging. Here we show that reactions of the potassium aluminyl complex K 2 [( NON )Al] 2 ( NON = 4,5‐bis(2,6‐diiso‐propylanilido)‐2,7‐di‐tert‐butyl‐9,9‐dimethylxanthene) with CO 2 , PhNCO and N 2 O all proceed via a common aluminium oxide intermediate. This highly reactive species can be trapped by coordination of a THF molecule as the anionic oxide complex [( NON )AlO(THF)] ‐ , which …
Carbon Monoxide Activation by a Molecular Aluminium Imide: C−O Bond Cleavage and C−C Bond Formation
Anionic molecular imide complexes of aluminium are accessible via a rational synthetic approach involving the reactions of organo azides with a potassium aluminyl reagent. In the case of K 2 [( NON )Al(NDipp)] 2 ( NON = 4,5‐bis(2,6‐di iso propylanilido)‐2,7‐di‐tert‐butyl‐9,9‐dimethyl‐xanthene; Dipp = 2,6‐di iso propylphenyl) structural characterization by X‐ray crystallography reveals a short Al‐N distance, which is thought to be due primarily to the low coordinate nature of the nitrogen centre. The Al‐N unit is highly polar, and capable of the activation of relatively inert chemical bonds, such as those found in dihydrogen and carbon monoxide. In the case of CO, uptake of two molecules of …
Synthesis, structure and reaction chemistry of a nucleophilic aluminyl anion.
The reactivity of aluminium compounds is dominated by their electron deficiency and consequent electrophilicity; these compounds are archetypal Lewis acids (electron-pair acceptors). The main industrial roles of aluminium, and classical methods of synthesizing aluminium–element bonds (for example, hydroalumination and metathesis), draw on the electron deficiency of species of the type AlR3 and AlCl31,2. Whereas aluminates, [AlR4]−, are well known, the idea of reversing polarity and using an aluminium reagent as the nucleophilic partner in bond-forming substitution reactions is unprecedented, owing to the fact that low-valent aluminium anions analogous to nitrogen-, carbon- and boron-centred…
Reversible, room-temperature C—C bond activation of benzene by an isolable metal complex
The activation of C-C bonds is of fundamental interest in the construction of complex molecules from petrochemical feedstocks. In the case of the archetypal aromatic hydrocarbon benzene, C-C cleavage is thermodynamically disfavored, and is brought about only by transient highly reactive species generated in situ. Here we show that the oxidative addition of the C-C bond in benzene by an isolated metal complex is not only possible, but occurs at room temperature and reversibly at a single aluminium center in [(NON)Al]- (where NON = 4,5-bis(2,6-diisopropylanilido)-2,7-di-tert-butyl-9,9-dimethylxanthene). Selectivity over C-H bond activation is achieved kinetically and allows for the generation…
CCDC 2095879: Experimental Crystal Structure Determination
Related Article: Matthew M. D. Roy, Jamie Hicks, Petra Vasko, Andreas Heilmann, Anne-Marie Baston, Jose M. Goicoechea, Simon Aldridge|2021|Angew.Chem.,Int.Ed.|60|22301|doi:10.1002/anie.202109416
CCDC 1899009: Experimental Crystal Structure Determination
Related Article: Jamie Hicks, Petra Vasko, Jose M. Goicoechea, Simon Aldridge|2019|J.Am.Chem.Soc.|141|11000|doi:10.1021/jacs.9b05925
CCDC 2008538: Experimental Crystal Structure Determination
Related Article: Jamie Hicks, Petra Vasko, Andreas Heilmann, Jose M. Goicoechea, Simon Aldridge|2020|Angew.Chem.,Int.Ed.|59|20376|doi:10.1002/anie.202008557
CCDC 1854972: Experimental Crystal Structure Determination
Related Article: Jamie Hicks, Akseli Mansikkamäki, Petra Vasko, Jose M. Goicoechea, Simon Aldridge|2019|Nature Chemistry|11|237|doi:10.1038/s41557-018-0198-1
CCDC 1972056: Experimental Crystal Structure Determination
Related Article: Andreas Heilmann, Jamie Hicks, Petra Vasko, Jose M. Goicoechea, Simon Aldridge|2020|Angew.Chem.,Int.Ed.|59|4897|doi:10.1002/anie.201916073
CCDC 1581596: Experimental Crystal Structure Determination
Related Article: Jamie Hicks, Petra Vasko, Jose M. Goicoechea, Simon Aldridge|2018|Nature (London)|557|92|doi:10.1038/s41586-018-0037-y
CCDC 1581598: Experimental Crystal Structure Determination
Related Article: Jamie Hicks, Petra Vasko, Jose M. Goicoechea, Simon Aldridge|2018|Nature (London)|557|92|doi:10.1038/s41586-018-0037-y
CCDC 1972053: Experimental Crystal Structure Determination
Related Article: Andreas Heilmann, Jamie Hicks, Petra Vasko, Jose M. Goicoechea, Simon Aldridge|2020|Angew.Chem.,Int.Ed.|59|4897|doi:10.1002/anie.201916073
CCDC 1899011: Experimental Crystal Structure Determination
Related Article: Jamie Hicks, Petra Vasko, Jose M. Goicoechea, Simon Aldridge|2019|J.Am.Chem.Soc.|141|11000|doi:10.1021/jacs.9b05925
CCDC 1972057: Experimental Crystal Structure Determination
Related Article: Andreas Heilmann, Jamie Hicks, Petra Vasko, Jose M. Goicoechea, Simon Aldridge|2020|Angew.Chem.,Int.Ed.|59|4897|doi:10.1002/anie.201916073
CCDC 1899006: Experimental Crystal Structure Determination
Related Article: Jamie Hicks, Petra Vasko, Jose M. Goicoechea, Simon Aldridge|2019|J.Am.Chem.Soc.|141|11000|doi:10.1021/jacs.9b05925
CCDC 1943804: Experimental Crystal Structure Determination
Related Article: Jamie Hicks, Andreas Heilmann, Petra Vasko, Jose M. Goicoechea, Simon Aldridge|2019|Angew.Chem.,Int.Ed.|58|17265|doi:10.1002/anie.201910509
CCDC 1943806: Experimental Crystal Structure Determination
Related Article: Jamie Hicks, Andreas Heilmann, Petra Vasko, Jose M. Goicoechea, Simon Aldridge|2019|Angew.Chem.,Int.Ed.|58|17265|doi:10.1002/anie.201910509
CCDC 1972054: Experimental Crystal Structure Determination
Related Article: Andreas Heilmann, Jamie Hicks, Petra Vasko, Jose M. Goicoechea, Simon Aldridge|2020|Angew.Chem.,Int.Ed.|59|4897|doi:10.1002/anie.201916073
CCDC 1972052: Experimental Crystal Structure Determination
Related Article: Andreas Heilmann, Jamie Hicks, Petra Vasko, Jose M. Goicoechea, Simon Aldridge|2020|Angew.Chem.,Int.Ed.|59|4897|doi:10.1002/anie.201916073
CCDC 1943805: Experimental Crystal Structure Determination
Related Article: Jamie Hicks, Andreas Heilmann, Petra Vasko, Jose M. Goicoechea, Simon Aldridge|2019|Angew.Chem.,Int.Ed.|58|17265|doi:10.1002/anie.201910509
CCDC 1854971: Experimental Crystal Structure Determination
Related Article: Jamie Hicks, Akseli Mansikkamäki, Petra Vasko, Jose M. Goicoechea, Simon Aldridge|2019|Nature Chemistry|11|237|doi:10.1038/s41557-018-0198-1
CCDC 2095878: Experimental Crystal Structure Determination
Related Article: Matthew M. D. Roy, Jamie Hicks, Petra Vasko, Andreas Heilmann, Anne-Marie Baston, Jose M. Goicoechea, Simon Aldridge|2021|Angew.Chem.,Int.Ed.|60|22301|doi:10.1002/anie.202109416
CCDC 2095877: Experimental Crystal Structure Determination
Related Article: Matthew M. D. Roy, Jamie Hicks, Petra Vasko, Andreas Heilmann, Anne-Marie Baston, Jose M. Goicoechea, Simon Aldridge|2021|Angew.Chem.,Int.Ed.|60|22301|doi:10.1002/anie.202109416
CCDC 1581594: Experimental Crystal Structure Determination
Related Article: Jamie Hicks, Petra Vasko, Jose M. Goicoechea, Simon Aldridge|2018|Nature (London)|557|92|doi:10.1038/s41586-018-0037-y
CCDC 1854973: Experimental Crystal Structure Determination
Related Article: Jamie Hicks, Akseli Mansikkamäki, Petra Vasko, Jose M. Goicoechea, Simon Aldridge|2019|Nature Chemistry|11|237|doi:10.1038/s41557-018-0198-1
CCDC 1899010: Experimental Crystal Structure Determination
Related Article: Jamie Hicks, Petra Vasko, Jose M. Goicoechea, Simon Aldridge|2019|J.Am.Chem.Soc.|141|11000|doi:10.1021/jacs.9b05925
CCDC 1581591: Experimental Crystal Structure Determination
Related Article: Jamie Hicks, Petra Vasko, Jose M. Goicoechea, Simon Aldridge|2018|Nature (London)|557|92|doi:10.1038/s41586-018-0037-y
CCDC 1943808: Experimental Crystal Structure Determination
Related Article: Jamie Hicks, Andreas Heilmann, Petra Vasko, Jose M. Goicoechea, Simon Aldridge|2019|Angew.Chem.,Int.Ed.|58|17265|doi:10.1002/anie.201910509
CCDC 1581600: Experimental Crystal Structure Determination
Related Article: Jamie Hicks, Petra Vasko, Jose M. Goicoechea, Simon Aldridge|2018|Nature (London)|557|92|doi:10.1038/s41586-018-0037-y
CCDC 1581593: Experimental Crystal Structure Determination
Related Article: Jamie Hicks, Petra Vasko, Jose M. Goicoechea, Simon Aldridge|2018|Nature (London)|557|92|doi:10.1038/s41586-018-0037-y
CCDC 1581592: Experimental Crystal Structure Determination
Related Article: Jamie Hicks, Petra Vasko, Jose M. Goicoechea, Simon Aldridge|2018|Nature (London)|557|92|doi:10.1038/s41586-018-0037-y
CCDC 1581599: Experimental Crystal Structure Determination
Related Article: Jamie Hicks, Petra Vasko, Jose M. Goicoechea, Simon Aldridge|2018|Nature (London)|557|92|doi:10.1038/s41586-018-0037-y
CCDC 1943807: Experimental Crystal Structure Determination
Related Article: Jamie Hicks, Andreas Heilmann, Petra Vasko, Jose M. Goicoechea, Simon Aldridge|2019|Angew.Chem.,Int.Ed.|58|17265|doi:10.1002/anie.201910509
CCDC 1899005: Experimental Crystal Structure Determination
Related Article: Jamie Hicks, Petra Vasko, Jose M. Goicoechea, Simon Aldridge|2019|J.Am.Chem.Soc.|141|11000|doi:10.1021/jacs.9b05925
CCDC 1581595: Experimental Crystal Structure Determination
Related Article: Jamie Hicks, Petra Vasko, Jose M. Goicoechea, Simon Aldridge|2018|Nature (London)|557|92|doi:10.1038/s41586-018-0037-y
CCDC 2008540: Experimental Crystal Structure Determination
Related Article: Jamie Hicks, Petra Vasko, Andreas Heilmann, Jose M. Goicoechea, Simon Aldridge|2020|Angew.Chem.,Int.Ed.|59|20376|doi:10.1002/anie.202008557
CCDC 1854974: Experimental Crystal Structure Determination
Related Article: Jamie Hicks, Akseli Mansikkamäki, Petra Vasko, Jose M. Goicoechea, Simon Aldridge|2019|Nature Chemistry|11|237|doi:10.1038/s41557-018-0198-1
CCDC 2008537: Experimental Crystal Structure Determination
Related Article: Jamie Hicks, Petra Vasko, Andreas Heilmann, Jose M. Goicoechea, Simon Aldridge|2020|Angew.Chem.,Int.Ed.|59|20376|doi:10.1002/anie.202008557
CCDC 1899008: Experimental Crystal Structure Determination
Related Article: Jamie Hicks, Petra Vasko, Jose M. Goicoechea, Simon Aldridge|2019|J.Am.Chem.Soc.|141|11000|doi:10.1021/jacs.9b05925
CCDC 1972055: Experimental Crystal Structure Determination
Related Article: Andreas Heilmann, Jamie Hicks, Petra Vasko, Jose M. Goicoechea, Simon Aldridge|2020|Angew.Chem.,Int.Ed.|59|4897|doi:10.1002/anie.201916073
CCDC 1581597: Experimental Crystal Structure Determination
Related Article: Jamie Hicks, Petra Vasko, Jose M. Goicoechea, Simon Aldridge|2018|Nature (London)|557|92|doi:10.1038/s41586-018-0037-y
CCDC 2008536: Experimental Crystal Structure Determination
Related Article: Jamie Hicks, Petra Vasko, Andreas Heilmann, Jose M. Goicoechea, Simon Aldridge|2020|Angew.Chem.,Int.Ed.|59|20376|doi:10.1002/anie.202008557
CCDC 1899007: Experimental Crystal Structure Determination
Related Article: Jamie Hicks, Petra Vasko, Jose M. Goicoechea, Simon Aldridge|2019|J.Am.Chem.Soc.|141|11000|doi:10.1021/jacs.9b05925
CCDC 2008541: Experimental Crystal Structure Determination
Related Article: Jamie Hicks, Petra Vasko, Andreas Heilmann, Jose M. Goicoechea, Simon Aldridge|2020|Angew.Chem.,Int.Ed.|59|20376|doi:10.1002/anie.202008557
CCDC 2010397: Experimental Crystal Structure Determination
Related Article: Jamie Hicks, Petra Vasko, Andreas Heilmann, Jose M. Goicoechea, Simon Aldridge|2020|Angew.Chem.,Int.Ed.|59|20376|doi:10.1002/anie.202008557
CCDC 2008539: Experimental Crystal Structure Determination
Related Article: Jamie Hicks, Petra Vasko, Andreas Heilmann, Jose M. Goicoechea, Simon Aldridge|2020|Angew.Chem.,Int.Ed.|59|20376|doi:10.1002/anie.202008557