Synthesis of 3-oxa- and 3-azabicyclo[4.1.0]heptanes by gold-catalyzed cycloisomerization of cyclopropenes.
Allyl 3,3-dimethylcyclopropenylcarbinyl ethers or sulfonamides undergo gold-catalyzed cycloisomerization leading to 5-isopropylidene-3-oxa- and 3-azabicyclo[4.1.0]heptanes in excellent yields and with high diastereoselectivities. These reactions constitute the first examples of intramolecular cyclopropanation of an alkene by a gold carbene generated by electrophilic ring opening of a cyclopropene in the presence of gold(I) chloride.
Miege
Frédéric
F
Laboratoire de Chimie Organique, ESPCI ParisTech, CNRS, 10 rue Vauquelin, 75231 Paris Cedex 05, France.
Meyer
Christophe
C
Cossy
Janine
J