Reactivity of a β-diketiminate-supported magnesium alkyl complex toward small molecules

Abstract

The reactivity of the butylmagnesium complex toward various small molecules has been investigated.

Synthesis and Reactivity of Heteroleptic Ga‐P‐C Allyl Cation Analogues

“…ligand backbone.N ucleophilic bond-forming reactions involving the g-carbon have been previously reported for bdiketiminate stabilized cationic transition metal [32] and Al complexes [33] as well as neutral metal complexes [34] with heteroallenes,t hat is,C O 2 ,C S 2 ,d iphenylketene,i so-(thio)cyanates,a nd other unsaturated substrates including oxygen and ethylene. [35] However,t ot he best of our knowledge,t he formation of at ripodal N,N',N'' ligand as observed in compound 7 was only reported for the reaction between [LMg(n-Bu)] 2 and phenylisothiocyanate, [36] while the CÀC bond forming reaction of LLi with t-BuNCO yielded the isocyanate insertion product [{(MeCN-2,6-i-Pr 2 C 6 H 3 ) 2 C-(CONH(t-Bu))}Li•TMEDA],i nw hich the Li cation is coordinated in an N,O-chelating mode. [37] The 1 HNMR spectrum of 6 shows resonances of the bdiketiminate ligand, the carbene and dmap.T he singlet at 5.42 ppm (g-CH)isup-field shifted compared to that of 4,and the resonance of the NMe 2 group is displayed at 3.15 ppm.…”

Backbone Reactivity of Lithium β‐Diketiminate (NacNac) Complexes with CO2, tBuNCO and iPrNCO

“…This seemed a pertinent choice given recent work by Ma et al. that explored the activation of small molecules, including isothiocyanates, by a magnesium alkyl NacNac complex . We decided to focus our efforts on the isoelectronic isocyanates since these compounds have a similar bonding situation to that in carbon dioxide, with the synthetic advantage that exact stoichiometric amounts of the liquid isocyanates can be easily added to reactions.…”

“…This seemed ap ertinentc hoice given recent work by Ma et al that explored the activation of small molecules, including isothiocyanates, by am agnesium alkyl NacNac complex. [29] We decided to focus our efforts on the isoelectronic isocyanates since these compoundsh ave a similar bonding situation to that in carbon dioxide, with the synthetic advantage that exact stoichiometric amountso ft he liquid isocyanates can be easily added to reactions. Insertion of isocyanates into s-block metal complexes is known, [30] albeit a systematic investigation of isocyanate fixation using lithium NacNac complexes is required to investigate chemoselectivity of such aprocess.…”

“…Such rearrangements have been observed before in small molecule fixation. Notably Fulton et al., used lead and tin NacNac complexes to activate phenyl isocyanate, and Ren and Ma utilised magnesium NacNac complexes to activate phenyl isothiocyanate . The diimine functionality present within 2 was also confirmed from the C 13 −N 1 and C 16 −N 2 bond lengths of 1.299(4) Å and 1.295(5) Å respectively, again comparable with the standard imine C−N bond length of 1.279 Å .…”

Synthesis and Reactivity of Heteroleptic Ga‐P‐C Allyl Cation Analogues

“…Chemie Forschungsartikel 2016 www.angewandte.de ligand backbone.N ucleophilic bond-forming reactions involving the g-carbon have been previously reported for bdiketiminate stabilized cationic transition metal [32] and Al complexes [33] as well as neutral metal complexes [34] with heteroallenes,t hat is,C O 2 ,C S 2 ,d iphenylketene,i so-(thio)cyanates,a nd other unsaturated substrates including oxygen and ethylene. [35] However,t ot he best of our knowledge,t he formation of at ripodal N,N',N'' ligand as observed in compound 7 was only reported for the reaction between [LMg(n-Bu)] 2 and phenylisothiocyanate, [36] while the CÀC bond forming reaction of LLi with t-BuNCO yielded the isocyanate insertion product [{(MeCN-2,6-i-Pr 2 C 6 H 3 ) 2 C-(CONH(t-Bu))}Li•TMEDA],i nw hich the Li cation is coordinated in an N,O-chelating mode. [37] The 1 HNMR spectrum of 6 shows resonances of the bdiketiminate ligand, the carbene and dmap.T he singlet at 5.42 ppm (g-CH)isup-field shifted compared to that of 4,and the resonance of the NMe 2 group is displayed at 3.15 ppm.…”