Zwitterionic Metal-Enolate or Equivalent: Generation and Capture

Decarboxylative Intramolecular [3 + 2] Cycloaddition of Cyclic Enol Carbonates: Construction of a Bicyclo[3.3.0]octanone Skeleton

Stereoselective synthesis of bicyclic cyclopentanones was achieved by sequential Tf2O-catalyzed decarboxylation and intramolecular [3 + 2] cycloaddition reactions of cyclic enol carbonates bearing an alkene unit. Four stereogenic centers in the obtained cyclopentanone were stereoselectively constructed. This method could be applied to the synthesis of various fused bicyclic products in moderate-to-good yields.

Decarboxylative 1,2-rearrangement of cyclic carbonates promoted by Lewis acid

A Lewis acid-mediated decarboxylative 1,2-rearrangement reaction of cyclic carbonates was developed. The selectivity of the migration in the decarboxylative 1,2-rearrangement of cyclic carbonates was opposite to that of the corresponding 1,2-diols under the same reaction conditions. This contrasting selectivity of the migration was confirmed in a variety of substrates.

Pd-Catalyzed asymmetric decarboxylation for the construction of spiro[4.5]deca-6,9-dien-8-ones featuring vicinal quaternary carbons

A Pd-catalyzed decarboxylative strategy for the asymmetric construction of spiro[4.5]deca-6,9-dien-8-ones is reported. The epimerization of the resultant products occurred under otherwise Pd-catalysis.