1-oxa-3-aza-2,4-disilacyclobutanes - Synthesis, X-ray structures, and reactivity

Lithium aminodi(tert-butyl)silanolate reacts with F3SiR to give the aminosi loxane (Me3C)(2)SiNH2-O-SiF2R [1; R = 2,4,6-(tBu)(3)C6H2] In the reaction o f 1 with BuLi a four-membered (Si-O-Si-NH) ring system 2 is formed [-(Me3C) (2)Si-O-SiFR-NH-]. The amino-1,3-disiloxane RSiF2-NH-Si(CME3)(2)-O-SiF2R (3 ) is obtained from dilithiated amino(di-tert-butyl)silanol and F3SiR. Compo und 1 reacts with BuLi with formation of a dimeric Lithium derivative throu gh the Li-N bond (4). In 4 the transannular Si Si distance was found to be 237.2 pm, which is the shortest distance so far found between two silicon a toms contained in four-membered rings. Compound 4 reacts with Me3SiOSO2CF3 with substitution of the lithium by the Me3Si group to give 5.