Isolation of a 1-Magnesium-2,3-disilacyclopropene and a Related Bis(disilenide).

Herein we report the first synthesis of a 1-magnesium-2,3-disilacyclopropene and a related bis(disilenide). Reduction of (boryl)tribromosilane (, boryl = (HCArN)B, Ar = 2,6-PrCH) with magnesium in THF afforded boryl-substituted magnesium complex [(boryl)Si]Mg(THF) () in good yield, whereas reduction of (boryl)trichlorosilane () with KC in THF led to the isolation of bridged alkoxy alkyl bis(disilenide) (THF)K(boryl)Si═Si(boryl)O(CH)(boryl)Si═Si(boryl)K(THF) () via ring opening of a THF molecule. X-ray diffraction analysis of confirmed the presence of the novel SiMg three-membered ring as well as the Si═Si double bond, which existed in a noticeably twisted B-Si-Si-B array. Complex also represents the first reported example of a stable disilyne dianion.