Synthesis and structures of a 3-sila-(beta)-diketiminatomagnesium bromide, ketenimide and triflate

The crystalline compounds [Mg(Br)(L)(thf)]·0.5Et2O [L = {N(R)C(C6H3Me2-2,6)}2SiR, R = SiMe3](1), [Mg(L){N=C=C(C(Me)=CH)2CH2} (D)2][D = NCC6H3Me2-2,6 (2), thf (3)] and [{Mg(L)}2{(mu)-OSO(CF3)O-(mu)}2](4) were prepared from (a) Si(Br)(R){C(C6H3Me2-2,6) =NR}2 and Mg for (1), (b)[Mg(SiR3)2(thf)2] and 2,6-Me2C6H3CN (5 mol for (2), 3 mol for (3)), and (c)(2)+ Me3SiOS(O)2CF3 for (4); a coproduct from (c) is believed to have been the trimethylsilyl ketenimide Me3SiN=C=C{C(Me)=CH}2CH2(5).