Anionic approaches to the construction of cyclopentanoids

One‐Pot Organocatalytic Domino Michael/α‐Alkylation Reactions: Direct Catalytic Enantioselective Cyclopropanation and Cyclopentanation Reactions

“…prostaglandins), [17,18] we became intrigued as to whether we could expand the scope of chiral-amine-catalyzed domino Michael/intramolecular a-alkylation reactions to the assembly of highly substituted cyclopentanones in an asymmetric fashion ( Scheme 2) . [19][20] Notably, during our initial studies Ley and co-workers disclosed an elegant organocatalytic nitrocyclopropanation of cyclohexanone.…”

Copper‐Catalyzed Synthesis of 1,2‐Disubstituted Cyclopentanes from 1,6‐Dienes by Ring‐Closing Kharasch Addition of Carbon Tetrachloride

“…[1] Over the past twenty years there has been high demand by the pharmaceutical and fine chemical industries for the development of different synthetic methods to cyclic compounds, particularly for five-membered rings (i.e., cyclopentanes, tetrahydrofurans, tetrahydropyrroles, etc). [2] Among them, the transition metal-catalyzed cyclization reactions of unsaturated substrates are undoubtedly one of the most useful synthetic procedures for the construction of five-membered ring systems.…”

Stereoselective Michael Additions of Phosphorylated Allyl Carbanions − Synthesis of Functionalized Cyclopentylphosphonates and Phosphane Oxides

“…We wished to explore the [3ϩ2] strategy for the synthesis of five-membered carbocycles from 3 because it offers the possibility of forming two carbonϪcarbon bonds under the same reaction conditions. [14,15] It was also of interest to determine the regiochemistry of Michael additions of P-allyl carbanions derived from 3, in view of the fact that anions derived from the analogous sulfone had undergone additions through the α-carbon atom, [13] while Haynes et al [16] have shown that the anions derived from allylic diphenylphosphane oxides react with Michael acceptors through the γ-carbon atom of the reagent.…”