Intramolecular epoxide ring opening cyclisation reactions involving guanidines

Catalysts for CO2/epoxide ring-opening copolymerization

This article summarizes and reviews recent progress in the development of catalysts for the ring-opening copolymerization of carbon dioxide and epoxides. The copolymerization is an interesting method to add value to carbon dioxide, including from waste sources, and to reduce pollution associated with commodity polymer manufacture. The selection of the catalyst is of critical importance to contr...

Highly active oligomeric (salen)co catalysts for asymmetric epoxide ring-opening reactions.

Cooperative bimetallic catalysis has been documented in several recently reported asymmetric epoxide opening reactions that display second-order kinetic dependence on catalyst, specific requirements for multiple metal ions, and/or pronounced catalyst nonlinear effects.1 In such systems, one metal is proposed to serve as Lewis acid for epoxide activation and another as counterion for the nucleop...

Intramolecular Povarov reactions involving 3-aminocoumarins.

A series of pentacyclic heterocyclic systems (15 examples, 69-89%) have been synthesized using intramolecular Povarov reactions involving 3-aminocoumarins and O-cinnamylsalicylaldehydes. The Povarov adducts are formed with high selectivity for the trans,trans relative stereochemistry in the newly-formed [6,6] fused ring system. One example of a Povarov adduct featuring a new [6,5] fused ring sy...

Reductive ring opening reactions of diphenyldihydrofullerenylpyrroles

The reductive ring opening reaction conditions for the simple [60]fullerenyldihydropyrrole 1 have been optimized to include acetic acid in the reaction mixture to rapidly protonate the anionic intermediate. Under these conditions, the ring opened dihydrofullerene 2 was obtained in 68% yield. Under slightly modified conditions and at −78 °C, the reductive bis-ring opening of the tethered trans-4...

reactivity and selectivity in epoxide - opening reactions promoted by water