Regiospecific\nMethylalumination of Silacyclopropenes:\nThe Access to Z‑1-Silyl-2-Aluminyl-Disubstituted Olefins

A methodology\nto access Z-1-silyl-2-aluminyl-disubstituted\nolefins\nis developed. It relies on the uncatalyzed ring opening of silacyclopropenes\nin the presence of a stoichiometric amount of trimethylaluminum. The\nresulting heterosubstituted alkenes exhibit a particular interaction\nbetween the electron-rich [Si–CH<sub>3</sub>] moiety and the\nelectron-deficient diorganoaluminyl group, resulting in similar geometrical\nfeatures due to the proximity of these two centers. This interaction\nis rationalized using experimental and theoretical descriptors. The\nregioselectivity and functional tolerance of the methylalumination\nwere also studied in the case of unsymmetrical silacyclopropenes,\nand the methodology ultimately transposed to the synthesis of a polymeric\norganoalane incorporating tricoordinated aluminum centers.