Two novel silyl-substituted stannylenes are reported: ArMesSnSi (SiMe3) 2 (SitBuPh2) (ArMes = 2, 6-Mes2C6H3, Mes = 2, 4, 6-Me3C6H2) and SnSi (SiMe3) 2 (SitBuPh2) 2, the latter representing a very rare example of a homoleptic disilyl stannylene Together with the known stannylene ArMesSnSi (SiMe3) 3, these systems are each shown to insert into the Au–Cl bond of (Ph3P) AuCl to form complexes of the type (Ph3P) Au (SnR2Cl) containing four coordinate stannyl ligands (where R = aryl or silyl group). Similar behavior is shown toward (Cy3P) AuI, yielding crystalline (Cy3P) AuSnI (ArMes) (Si (SiMe3) 3) in the case of ArMesSnSi (SiMe3) 3. Subsequent iodide abstraction to yield (Cy3P) AuSn (ArMes) (Si (SiMe3) 3) + can be achieved using LiAl (ORf) 4 (Rf = −C (CF3) 3), facilitated by the long tin–halide bond and strongly electron-donating tertiary phosphine ligand. This cationic complex represents the first structurally characterized example of a simple (two-coordinate) stannylene ligand bound to a gold center in a manner analogous to classical Au (I) carbene complexes.
Murray et al. (Thu,) studied this question.