Novel organometallic reagents: geminal dianionic derivatives of the heavy group 14 elements.

This Forum review describes the most recent achievements in the novel prospective field of highly reactive main-group organometallics, namely, geminal dianionic derivatives of the heavy group 14 elements (Si, Ge, Sn). A brief historical introduction to the topic is followed by discussion of the current state of affairs in the field of stable derivatives and prospects for future efforts, highlighting our own synthetic approach and recent results. The most important experimental contributions, including synthesis of 1,1-dilithiosilane, -germane, and -stannane derivatives; dilithio(halo)silanes (lithiosilylenoids); metallole 1,1-dianions; and heavy analogues of the cyclobutadiene dianion derivatives, are presented, along with a discussion of the synthetic applications of the above-mentioned organometallic compounds.