Our group is interested in the development of skeletal transformations using geminal and vicinal organomultimetallic species. In this lecture, our recent advances in 1) carbon-atom transfer reactions using dinuclear chromium carbide species1 and 2) vic-dimetalloalkenes for skeletal transformations2-4 will be introduced.
- A chromium carbide complex was quantitatively formed by mixing CBr4 and CrBr2 in THF. The chromium carbide complex reacted with various unsaturated compounds such as alkenes and alkynes to construct spiropentanes and cyclopropenylidenes, respectively. Sequential reactions of the chromium carbide with alkene and then carbonyl compounds afforded alkylidenecyclopropanes.
- Reduction of alkynes with sodium metal in the presence of metal halides (RMgX, MgBr2, ZnCl2, and R2AlCl) resulted in the formation of the corresponding trans-1,2-dimetalloalkene. The vic-dimagnesioalkenes and dizincioalkenes reacted with various electrophiles to yield tetrasubstituted alkenes stereoselectively. Reaction of the vic-dialuminoalkenes with formaldehyde resulted in dearomatization of the aryl group to give cyclohexadiene 1,4-diols.
(1) Kurogi, T.; Irifune, K.; Takai, K. Chem. Sci. 2021, 12, 14281–14287.
(2) Takahashi, F.; Kurogi. T.; Yorimitsu, H. Nat. Synth. 2023, 2, 162–171.
(3) Yamaguchi, H.; Takahashi, F.; Kurogi, T.; Yorimitsu, H. Chem. Asian J. 2024, 19, e202400384.
(4) Yamaguchi, H.; Takahashi, F.; Kurogi, T.; Yorimitsu, H. Synthesis 2024, 56, 3307–3313.