Oxidation of phenacetin and related amides to their hydroxamic acids. Crystal structures of the dioxomolybdenum(VI) hydroxamates derived from phenacetin and acetanilide

Oxygen Abstraction Reactions of N-Substituted Hydroxamic Acids with Molybdenum(V) and Vanadium(III) and -(IV) Compounds

“…Thus the Mo−O(ligand) bonds trans to the terminal Mo−O bonds are elongated compared to the cis M−O(ligand) bonds, e.g. in 1 , n = 4, trans-Mo-O(ligand) = 2.19Å, which compares closely with those in ref ; e.g. trans-Mo−O(average) = 2.20 Å over cis-Mo−O(average) 2.02 Å.…”

“…Clearly both complexes are monomeric so cluster formation in FABMS must arise under the conditions of the method. In both 1 and 2 , the molybdenum atoms lie in a distorted octahedral environment similar to those in the molybdenum complexes of phenacetin and acetanilide . Thus the Mo−O(ligand) bonds trans to the terminal Mo−O bonds are elongated compared to the cis M−O(ligand) bonds, e.g.…”

“…To the best of our knowledge, the only analogous molybdenum structures are those of the hydroxamic acids (HA) derived from two analgesics, phenacetin and acetanilide, MoO 2 A 2 . In both cases the ligand arrangement about the Mo atom is distorted octahedral with the dioxo oxygens bonded cis to each other …”

Crystal structure of bis(pivaloylhydroxamato-κ2 O,O′)copper(II)

“…Though the survey did not contain any information about complexes with pivaloylhydroxamic acid, there are two reports devoted to structural studies of Th 4+ (1180613 and 1180614; Smith & Raymond, 1981) and MoO 2 2+ (763210-763214; Dzyuba et al, 2010) complexes with structurally similar ligands (N-isopropyl-2,2dimethylpropanehydroxamate, N-isopropyl-3,3-dimethylbutanehydroxamate and decano-, N-methyl-decano-, Nmethyl-hexano-, N-methyl-1-adamantano-or N-tert-butylhexanohydroxamates, respectively). It should be mentioned that coordination of hydroxamate ligands in the O,O 0chelating mode is quite typical (Tedeschi et al, 2003;Seitz et al, 2007a,b;Brewer & Sinn, 1981) and the CSD contains many records with such binding in various mononuclear bis-hydroxamate complexes (e.g. Drovetskaia et al, 1996;Li et al, 2004;Fisher et al, 1989;Harrison et al, 1976), which are usually coordinated in the trans-mode with respect to each other (Gaynor et al, 2001;Lasri et al, 2012;Casellato et al, 1984).…”

Dioxomolybdenum(VI) Complexes as Catalytic Neutral Esterification Agents

“…There are many reactions which are facilitated by dioxomolybdenum(VI) complexes such as transformation of alkenes to epoxides, 6 sulfides to sulfoxides, 7 secondary alcohols to ketones, 8 aldehydes to carboxylic acids, 9 azobenzenes to azoxybenzenes, 10 N-heterocyclics to N-oxides, 11 amides to hydroxamates 12 and more complex reactions. 13 Amongst dioxomolybdenum(VI) complexes, dioxomolybdenum(VI) acetylacetonate i.e., [MoO 2 (acac) 2 ] has been widely used as a catalyst in many organic transformations (due to its low cost and ease of handling) such as methoxymethylation of alcohols, protective tetrahydropyranylation of alcohols and phenols, 15 dehydration of tertiary alcohols to olefines, 16 β-selective epoxidation of cholesterol esters with molecular oxygen 17 and deprotection of acetals.…”