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The chemical behavior of cyclopropyl-substituted alkynes has been probed using the reaction conditions of ruthenium-catalyzed oxidative C-H/O-H and C-H/N-H bond functionalizations. The oxidative annulations proceeded with complete conservation of all cyclopropane fragments and allowed for the one-step preparation of synthetically useful cyclopropyl-substituted isocoumarins and isoquinolones with high regioselectivities and chemical yields. The connectivities of the key heterocyclic products were unambiguously established by X-ray diffraction analysis.

The synthesis of 1,2-di-tert-butyl-3,3-dimethylcyclopropene (I) is performed and its IR and Raman spectra are measured. Optimized geometries of I are obtained at the HF/6-31G* and CCSD/cc-pVDZ levels. The ab initio calculated spectra are used for the assignments of the experimental spectral data. The results obtained are compared with the corresponding data for 3,3-dimethylbut-1-ene and 3,3-dimethylcyclopropene. These experimental data and the total vibrational analysis of I supplement the information obtained in the series of investigations of tert-butyl, trimethylsilyl, trimethylgermyl, trimethylstannyl, and trimethylplumbyl derivatives of 3,3-dimethylcyclopropene., (Copyright 2009 Elsevier B.V. All rights reserved.)

Ring conservation was observed in the first catalytic intermolecular hydroarylation of methylenecyclopropanes via C-H bond functionalization, a remarkable reactivity mode for a transformation proceeding through (cyclopropylcarbinyl)metal intermediates.