Publications by authors named "Joseph Banning"

The synthesis and crystal structure of the heterocyclic explosive bis(nitroxymethylisoxazolyl) furoxan, C H N O , are described. In addition, we report its physical properties and theoretical performance. This material was found to exhibit standalone melt-castable explosive properties, with a melting point of 89.

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A highly chemo- and diastereoselective protocol toward amino-substituted donor-acceptor cyclopropanes via the formal nucleophilic displacement in bromocyclopropanes is described. A wide range of N-nucleophiles, including carboxamides, sulfonamides, azoles, and anilines, can be efficiently employed in this transformation, providing expeditious access to stereochemically defined and densely functionalized cyclopropylamine derivatives.

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A diastereoconvergent formal nucleophilic substitution of bromocyclopropanes with oxygen- and sulfur-based nucleophiles is described. The reaction proceeds via in situ formation of a highly reactive cyclopropene intermediate and subsequent diastereoselective addition of a nucleophile across the strained C═C bond. Three alternative means of controlling the diastereoselectivity of addition have been demonstrated: (1) thermodynamically driven epimerization of enolizable carboxamides, (2) steric control by bulky substituents, and (3) directing effect of carboxamide or carboxylate functions.

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A chemo- and diastereoselective protocol for the formal nucleophilic substitution of 2-bromocyclopropylcarboxamides with secondary amides is described. This method allows for convergent and highly selective synthesis of trans-β-aminocyclopropane carboxylic acid derivatives.

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A new, general, and chemoselective protocol for the formal nucleophilic substitution of 2-bromocyclopropylcarboxamides is described. A wide range of alcohols and phenols can be employed as pronucleophiles in this transformation, providing expeditious access to trans-cyclopropanol ethers. A new mode of the selectivity control through a thermodynamic equilibrium is realized, alternative to the previously described steric and directing modes.

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A highly diastereoselective formal nucleophilic substitution of bromocyclopropanes with oxygen- and nitrogen-based nucleophiles was demonstrated. The reaction proceeds via a base-assisted dehydrohalogenation producing a cyclopropene intermediate, which subsequently undergoes addition of a pronucleophile across the strained double bond. Very high chemoselectivity toward addition of primary and secondary alkoxides, as well as N-nucleophiles, in the presence of tert-butoxide base was observed, whereas phenoxides did not undergo addition under these reaction conditions.

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