Stereoselective synthesis of 2-carbamoyl-2-cyanocyclopropanecarboxylates by tandem oxidative cyclization and neighboring group-assisted decarboxylation.

In this paper, we report a facile synthesis of 2-carbamoyl-2-cyanocyclopropanecarboxylates through a tandem iodosobenzene/tetrabutylammonium iodide-induced oxidative cyclization and a subsequent neighboring group-assisted decarboxylation of the Michael adducts of 2-cyanoacetamides with α,β-unsaturated malonates. This method affords the desired highly functionalized cyclopropanes in moderate to good yields and with excellent diastereoselectivities. In addition, the reaction proceeds smoothly under mild conditions and with good functional group tolerance.