Carbon dioxide undergoes a Pd-catalyzed [3+2] cycloaddition with trimethylenemethane (TMM) under mild conditions (1 atm, 75 degrees C, 30 min) to produce a gamma-butyrolactone product in 63% yield, when the Pd-TMM complex is generated from 2-(acetoxymethyl)-3-(trimethylsilyl)propene. The reaction reported here is more rapid than the all-carbon [3+2] cycloaddition, and only the gamma-butyrolactone is produced in a competition experiment. With substituted substrates, the reaction is completely regioselective, producing the product derived from the kinetic Pd-TMM complex.

2008 Furan derivatives R 0060 Palladium-Catalyzed [3 + 2] Cycloaddition of Carbon Dioxide and Trimethylenemethane under Mild Conditions. -A variety of γ-butyrolactones is produced via the title reaction. The optimized conditions refer only to the product (IIIa). -(GRECO*, G. E.; GLEASON, B. L.; LOWERY, T. A.; KIER, M. J.; HOLLANDER, L. B.; GIBBS, S. A.; WORTHY, A. D.; Org. Lett. 9 (2007) 19, 3817-3820; Dep. Chem., Goucher Coll., Baltimore, MD 21204, USA; Eng.) -R. Steudel 06-098