Synthesis of Aminobismuthanes via Me₃SnCl Elimination

Abstract

Abstract. The synthesis of N-trimethylstannylamines of the type RN(SnMe 3 )H (stannylated anilines) with the sterically encumbered substituents R such as Ter [terphenyl, 2,6-bis(2,4,6-trimethylphenyl)-phenyl], Ar* [2,6-bis(diphenylmethyl)-4-methylphenyl], and Mes* (supermesityl, 2,4,6-tri-tert-butylphenyl) is described. These stan-

Balancing Donor‐Acceptor and Dispersion Effects in Heavy Main Group Element π Interactions: Effect of Substituents on the Pnictogen⋅⋅⋅π Arene Interaction

“…Furthermore, such weak interactions might also play a crucial role in some biological systems as discussed by Frontera and coworkers . In addition to numerous examples showing intermolecular pnicogen⋅⋅⋅π arene interaction, systems with intramolecular interaction were less frequently reported, especially for bismuth . However, these instances demonstrate that this rather weak interaction enables stabilization of unusual compounds and might support catalytic processes …”

Reactivity of TerN(SiMe3)BiCl2—Synthesis of an Aminobismuthenium Cation and TerN(SiMe3)Bi(N3)2

“…In particular, N -(trimethylsilyl)­aminobismuthanes with different sterically demanding groups at the nitrogen atom have been studied intensively. The Me 3 Si group was introduced to increase the steric protection of the precursor, but at the same time, “Me 3 Si + ”, also known as “big proton”, can easily be removed by strong nucleophiles such as X – (X = halogen, OR) to afford, for instance, low-valent N–Bi cations. ,,, However, on some occasions the elimination of the Me 3 Si group was impossible, contrary to results obtained with lighter congeners (RN­(SiMe 3 )­PnCl 2 ; Pn = P, As; R = Mes*). − In these cases, use of stannylated species rather than silylated species often represented a more favorable reaction pathway …”

“…Aside from their steric protection, terphenyls are also capable of stabilizing bismuth compounds by π-arene interactions with the bismuth center, a typical structural motif frequently found in bismuth compounds. This long-known phenomenon (also known as “Menshutkin” interactions or “Menshutkin-type” complexes) is not limited to bismuth but is also observed for antimony and arsenic compounds , and has been intensively investigated by experimental and theoretical studies. − Often, such interactions are intermolecular (e.g., with solvent molecules), , but some examples of intramolecular Menshutkin-type complexes are known in bismuth compounds bearing bulky arene substituents. ,,, It has been demonstrated that such π-arene interactions have a significant stabilizing effect, for example, on highly reactive aminochlorobismuthenium cations …”

A Bismuth–Arene σ‐Complex – On the Edge of Menshutkin‐Type Complexes

“…The formation of the C–C coupling product 3b clearly demonstrated the instability of 2 + in the presence of WCAs as counter ions. C–C coupling and C–H activation of Bi compounds under elimination of “bismuth black” were observed on several occasions in the past decade and seem to represent a common pathway of decomposition of such compounds , , , . Unfortunately, C–C coupling product 3b could only be obtained in very low yields as a side product and could not be fully characterized.…”