Thermodynamic Control of Diastereoselectivity in the Formal Nucleophilic Substitution of Bromocyclopropanes
作者:Joseph E. Banning、Anthony R. Prosser、Michael Rubin
DOI:10.1021/ol100187c
日期:2010.4.2
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.
Formal Substitution of Bromocyclopropanes with Nitrogen Nucleophiles
作者:Joseph E. Banning、Jacob Gentillon、Pavel G. Ryabchuk、Anthony R. Prosser、Andrew Rogers、Andrew Edwards、Andrew Holtzen、Ivan A. Babkov、Marina Rubina、Michael Rubin
DOI:10.1021/jo4011798
日期:2013.8.2
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 cydopropylamine derivatives.
Formal Nucleophilic Substitution of Bromocyclopropanes with Azoles
A highly diastereoselective protocol for the formal nucleophilic substitution of 2-bromocyclopropylcarboxamides with azoles is described. A wide range of azoles, including pyrroles, indoles, benzimidazoles, pyrazoles, and benzotriazoles, can be efficiently employed as pronucleophiles in this transformation, providing expeditious access to N-cyclopropyl heterocycles.
Diastereoselectivity Control in Formal Nucleophilic Substitution of Bromocyclopropanes with Oxygen- and Sulfur-Based Nucleophiles
作者:Joseph E. Banning、Anthony R. Prosser、Bassam K. Alnasleh、Jason Smarker、Marina Rubina、Michael Rubin
DOI:10.1021/jo200368a
日期:2011.5.20
diastereoconvergent formal nucleophilicsubstitution 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: