Synthesis and Development of Novel Main Group Element Compounds having Tin-based Steric Protection Group

近年来，具有高效空间保护基团的活性主族元素化合物因其独特的化学性质而备受关注。虽然空间保护基团的许多成功和发展已经被报道，但在许多情况下，中心原子被限制在碳上。在本研究项目中，我们一直在研究锡基空间保护基团对活性官能团的动力学稳定作用。例如，三(9-三苯基)锡基(Trp_3SN-)已被证明是-SOH功能的有效空间保护基团。此外，我们还合成并研究了中心锡原子上含有三个9，10-二氢-9，10-亚乙基菲-L基团(DBB_3SN-)的相关化合物作为一种新型的锡基空间保护基团。此外，还研究了甲基双(9-三丁酰基)锡基(Trp_2MeSn-)的合成和官能化，并对几种Trp_3Sn-化合物进行了静态和动态立体化学研究。对Trp3SnX(X=全息烯烃，烷基)的X-射线结晶学研究表明，三个Trp基团相互啮合，形成近C3的手性构象。在溶液中，用VT-核磁共振方法研究了Trp3SnX化合物的对映异构化过程。

In recent years there has been much interest in the reactive main group element compounds having an efficient steric protection group because of their unique chemical properties. Although many successes and developments of the steric protection groups have been reported, the central atom has been limited to carbon in many cases. In this research project, we have been investigating on the tin-based steric protection groups for the kinetic stabilization of reactive functional groups. For example, tris(9-triptycyl)stannyl group (Trp_3Sn-) has been shown as an effective steric protection group for-SOH function. Also, we synthesized and investigated on the related compounds bearing three 9,10-dihydro-9,10-ethenoanthracen-l-yl (Dbb) groups on a central tin atom (Dbb_3Sn-) as a novel tin-based steric protection group. Also, the synthesis and functionalization of methylbis(9-triptycyl)stannyl group (Trp_2MeSn-) has been studied.Moreover, static and dynamic stereochemistry of several Trp3Sn-compounds were studied. X-ray crystallography of the Trp3SnX (X= hologenes, alkyl groups) showed that the three Trp goups meshed with each other like bevel gears and formed near-C3 chiral conformation. In solution, the process of enantiomerization of those Trp3SnX compounds has been investigated by VT-NMR method.