We present full details of the unique reactivities of the newly developed dianion-type bulky zincate, dilithium tetra-tert-butylzincate (tBu(4)ZnLi(2)). With this reagent, halogen-zinc exchange reaction of variously functionalized haloaromatics and anionic polymerization of N-isopropylacrylamide (NIPAm)/styrene with excellent chemoselectivity were realized. Halogen-zinc exchange reaction followed by electrophilic trapping with propargyl bromide provided a convenient route to functionalized phenylallenes, particularly those with electrophilic functional groups (such as cyano, amide and halogens). Spectral and computational studies of the structure in the gas and liquid phases indicated extraordinary stabilization of this dianion-type zincate by its bulky ligands.
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http://dx.doi.org/10.1002/chem.200800536 | DOI Listing |
Chem Commun (Camb)
April 2022
Departement für Chemie, Biochemie und Pharmazie, Universität Bern, Switzerland.
Combining a bulky bis(amide) and a reactive one-coordinate TMP (2,2,6,6-tetramethylpiperidide) ligand, a new mixed K/Zn heteroleptic base has been developed for regioselective zincation of fluoroarenes. This special ligand set allows for trapping and structural authentication of the first intermediates of direct Zn-H exchange of fluoroarenes obtained deprotonative metallation, providing mechanistic insights of the processes involved.
View Article and Find Full Text PDFAdv Mater
May 2022
Department of Chemistry and Biochemistry, Northern Illinois University, DeKalb, IL, 60115, USA.
One major challenge of aqueous Zn-MnO batteries for practical applications is their unacceptable performance below freezing temperatures. Here the use of simple Zn(ClO ) aqueous electrolytes is described for all-weather Zn-MnO batteries even down to -60 °C. The symmetric, bulky ClO anion effectively disrupts hydrogen bonds between water molecules and provides intrinsic ion diffusion even while frozen, and enables ≈260 mAh g on MnO cathodes at -30 °C .
View Article and Find Full Text PDFChemistry
September 2013
WestCHEM, Department of Pure and Applied Chemistry, University of Strathclyde, Glasgow, G1 1XL (UK).
Dalton Trans
January 2010
WestCHEM, Department of Pure and Applied Chemistry, University of Strathclyde, Glasgow, UK G1 1XL.
Four novel heterobimetallic ate complexes containing cis-2,6-dimethylpiperidide (cis-DMP) have been prepared and characterised. Two contain one cis-DMP ligand, namely the bisalkyl-amido lithium, and sodium zincates [(TMEDA) x MZn(cis-DMP)(tBu)2] (M = Li for 1, Na for 2). Both 1 and 2 are synthesised by co-complexation of the respective alkali metal amide with di-tert-butylzinc in the presence of a molar equivalent of N,N,N',N'-tetramethylethylenediamine (TMEDA) in a hydrocarbon medium.
View Article and Find Full Text PDFAcc Chem Res
June 2009
WestCHEM, Department of Pure and Applied Chemistry, University of Strathclyde, Glasgow G1 1XL, UK.
Metalation, one of the most useful and widely used synthetic methodologies, transforms a relatively inert carbon-hydrogen bond to a more labile carbon-metal bond. Until recently, most organometallic reagents that facilitate this process have combined strongly electropositive metals, such as lithium, with organic reagents to form highly polar and, by implication, highly reactive carbon-metal bonds. For example, the alkyllithium reagents and bulky lithium amides that are commonly employed for this purpose can suffer from low functional group tolerance.
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