Polar substituent effects in 1,3-disubstituted bicyclo[1.1.1]pentanes

Abstract

The pAa's of eight 3-substituted bicyclo [1.1.1] pentanecarboxylic acids have been measured and found to correlate well with constants. The value of (2.23 ± 0.12) is large but not large enough to propose any special perturbation of normal field-inductive effects by the close proximity (about 1.88 Á) of the bridgehead carbons. Also determined were the products and rates of solvolyses of the p-nitrobenzoates of three 3-substituted l-(2-hydroxy-2propyl)bicyclo [1.1.1] pentanes. The products were primarily unrearranged, and the rates again showed no surprising substituent effects. A practical synthesis of 1,3-disubstituted bicy clo [ 1.1.1 ]pentanes has been developed and is described.Bicyclo [1.1.1] pentane (1) has the very special property 0

Nonconjugated Hydrocarbons as Rigid‐Linear Motifs: Isosteres for Material Sciences and Bioorganic and Medicinal Chemistry

“…This involved a new five‐step synthetic route from commercially available starting materials with an overall yield of 32 %. This is an improvement over the original seven‐step synthesis which had a yield of 14 % and incorporated the use of the corrosive hydrazoic acid reagent . The key step involved a novel, potentially versatile method using metal‐free homolytic alkylation.…”

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Improving Nonspecific Binding and Solubility: Bicycloalkyl Groups and Cubanes as para‐Phenyl Bioisosteres

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A Facile Route to Bridgehead Disubstituted Bicyclo[1.1.1]pentanes Involving Palladium-Catalyzed Cross-Coupling Reactions

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