Publications by authors named "Kenneth Turnbull"

Sydnones, which contain a mesoionic five-membered heterocyclic ring, are more stable if synthesized with an aromatic substutuent at the N3 position. In the title compound {sys-tematic name: 4-acetyl-3-[2-(eth-oxy-carbon-yl)phen-yl]-1,2,3-oxa-diazol-3-ylium-5-olate}, C13H12N2O5, the aromatic substitutent is 2-(eth-oxy-carbon-yl)phenyl. Intra- and inter-molecular hydrogen bonds are observed.

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In general, sydnone compounds are synthesized with an aromatic substituent at the N-3 position and this feature adds to the stability of the mesoionic five-membered heterocyclic ring. In the title compound, C26H19BrN3O2P, the aromatic substitutent is tri-phenyl-phosphine 4-bromo-phenyl-imide. The dihedral angle between the planes of the sydnone and the attached phenyl ring is 45.

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Sydnones are unusual mesoionic compounds containing a five-membered heterocyclic ring. Generally for stability, substitution at the N-3 position by an aromatic fragment is necessary. In the title compound, C(10)H(9)N(3)O(3), the aromatic substitutent is 2-acetamido-phenyl.

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As part of an effort to develop a spectroscopic structure-property relationship in platinum acetylide oligomers, we have prepared a series of mesoionic bidentate Pt(PBu3)2L2 compounds containing sydnone groups. The ligand is the series o-Syd-(C6H4-C[triple bond]C)n-H, where n = 1-3, designated as Syd-PEn-H. The terminal oligomer unit consists of a sydnone group ortho to the acetylene carbon.

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Investigating reactions of functionalized p-quinone methides continues to advance our design of a reagent being developed for controlled, in situ modification of DNA via phosphodiester alkylation. Previously reported investigations of p-quinone methides derived from catechols allowed for trapping of isolable trialkyl phosphates for characterization and mechanistic information. However, lactone formation with these derivatives required long reaction times, resulting in an unfavorable mixture of trialkyl phosphate and hydrolysis products.

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Despite the wide array of studies involving DNA alkylation and cleavage with quinone methide generating compounds, there have been no reports on the alkylation of phosphodiesters with quinone methides. We have investigated the reaction of dialkyl phosphates with a p-quinone methide in order to determine the potential for alkylation to produce trialkyphosphates. These studies have revealed that a phosphodiester can be alkylated with a p-quinone methide when promoted by a Brønsted acid.

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