Summary: Catalytic and Photochemical Cyclopropanation of
Alkenes with Methyl Diazo(trialkylsilyl)acetates: Steric
Effects and Thermodynamic Stabilities of Cyclopropanes
Gerhard Maas*,
Abteilung Organische Chemie I, Universita¨t Ulm, Albert-Einstein-Allee 11,
D-89081 Ulm, Germany
Mechthild Alt, Dieter Mayer, and Uwe Bergstra¨sser
Fachbereich Chemie, Universita¨t Kaiserslautern, Erwin-Schro¨dinger-Strasse,
D-67663 Kaiserslautern, Germany
Stepan Sklenak, Prince Xavier, and Yitzhak Apeloig*
Department of Chemistry and the Lise MeitnersMinerva Center for Computational Quantum
Chemistry, TechnionsIsrael Institute of Technology, Haifa 32000, Israel
Received June 8, 2001
Diazo esters 1 (N2dC(SiR3)COOMe; R ) Me (1a), Et (1b), i-Pr (1c)) have been decomposed
in styrene, 1-hexene, and cyclohexene under Cu, Rh, or Ru catalysis as well as by
photochemical means with the objective to evaluate the effectiveness and diastereoselectivity
of the respective cyclopropanation reaction. With styrene and 1-hexene as substrates, the
ability of the catalysts followed the order CuOTf > [Ru2(CO)4(µ-OAc)2]n Rh2(OAc)4, but
even CuOTf (copper(I) triflate) did not promote cyclopropanation of 1-hexene with the bulky
1c. Cyclopropanation of cyclohexene with 1a,b succeeded only with the ruthenium catalyst.

Source: Apeloig, Yitzhak - Department of Chemistry, Technion, Israel Institute of Technology
Sklenak, Stepan - Department of Chemical Physics, Jaroslav Heyrovsky Institute of Physical Chemistry

Collections: Chemistry