Structural and Mechanistic Studies of Halogenation of a Tin(II) N-Functionalized Alkyl

The halogenation of the tin(II) alkyl SnR12 (1) [R1 = CH(SiMe3)C9H6N-8] to give R12SnX2
[X = F (2), Cl (3), Br (4), I (5)] was investigated by reacting 1 with SnX2 (X = F, Cl, Br, and
I), PbCl2, BCl3, and X2 (X = Br, I), respectively. 1H, 119Sn NMR and X-ray analysis showed
that the reactions with SnX2 under a milder experimental condition afforded intermediate
compounds, R12Sn→SnX2 [X = Cl (6), Br (7)] and R1SnX [X = Cl (8), Br (9)]. Further heating
gave the final products R2SnX2. The X-ray structures of 2−6 and 9 have been determined.
The dynamic exchange process between diastereoisomers of R1SnX (X = Cl, Br) has been
studied by variable-temperature 1H and 119Sn NMR spectroscopy.

以二烷基锡(II)配合物SnR₁₂（1，其中R₁ = CH(SiMe₃)C₉H₆N-8）为起始原料，分别与卤化锡(II) SnX₂（X=F、Cl、Br、I）、氯化铅(PbCl₂)、三氯化硼(BCl₃)以及单质卤素X₂（X=Br、I）进行反应，对其卤化生成R₁₂SnX₂[X=F(2)、Cl(3)、Br(4)、I(5)]的过程展开了系统研究。通过1H、119Sn核磁共振（NMR）波谱与X射线分析结果表明，在温和实验条件下与SnX₂的反应可生成中间体R₁₂Sn→SnX₂[X=Cl(6)、Br(7)]与R₁SnX[X=Cl(8)、Br(9)]。对反应体系进一步加热后，可得到最终产物R₁₂SnX₂。目前已完成化合物2~6及9的X射线晶体结构解析。此外，通过变温1H和119Sn核磁共振波谱，对R₁SnX（X=Cl、Br）的非对映异构体间的动态交换过程进行了研究。