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6943248 
Journal Article 
eta(2) Coordination of Electron -Deficient Arenes with Group 6 Dearomatization Agents 
Smith, JA; Simpson, , SR; Westendorff, KS; Weatherford-Pratt, J; Myers, JT; Wilde, JH; Dickie, DA; Harman, WD; , 
2020 
1 
Organometallics
ISSN: 0276-7333
EISSN: 1520-6041 
AMER CHEMICAL SOC 
WASHINGTON 
39 
13 
2493-2510 
English 
33456103 
WOS:000551358900020 
The exceptionally p-basic metal fragments {MoTp(NO)(DMAP)} and {WTp(NO)(PMe3)} (Tp = tris(pyrazolyl)borate; DMAP = 4-(N,N-dimethylamino)pyridine) form thermally stable eta(2)-coordinated complexes with a variety of electron-deficient arenes. The tolerance of substituted arenes with fluorine-containing electron withdrawing groups (EWG; -F, -CF3, -SF5) is examined for both the molybdenum and tungsten systems. When the EWG contains a pi bond (nitriles, aldehydes, ketones, ester), eta(2) coordination occurs predominantly on the nonaromatic functional group. However, complexation of the tungsten complex with trimethyl orthobenzoate (PhC(OMe)(3)) followed by hydrolysis allows access to an eta(2)-coordinated arene with an ester substituent. In general, the tungsten system tolerates sulfur-based withdrawing groups well (e.g., PhSO2Ph, MeSO2Ph), and the integration of multiple electron-withdrawing groups on a benzene ring further enhances the pi-back-bonding interaction between the metal and aromatic ligand. While the molybdenum system did not form stable eta(2)-arene complexes with the sulfones or ortho esters, it was capable of forming rare examples of stable eta(2)-coordinated arene complexes with a range of fluorinated benzenes (e.g., fluorobenzene, difluorobenzenes). In contrast to what has been observed for the tungsten system, these complexes formed without interference of C-H or C-F insertion.