Functionalization of Mesoporous Silica Surface by Anchoring of Chemically-active Groups and Applications to Precise Organic Synthesis

成功制备了孔结构均匀的介孔氧化硅。化学活性基团如氨丙基、辛基和环氧环己基被锚定在MS表面上，分别命名为MS-NH 2、MS-C8和MS-ep。还获得了在骨架结构中包含乙烯链、氨丙基、硫醇和吡啶鎓基团的介孔有机二氧化硅（分别缩写为MOS-Ey、MOS-NH 2、MOS-SH和MOS-Py）。1.乙醛在MS-NH_2上的吸附：氨丙基的锚定大大提高了乙醛的吸附性能。特别是在低浓度下，吸附剂在MS-NH 2中的吸附能力随着孔径的减小而增加。2.表面稳定性和疏水/亲油控制：MS-C8表现出疏水特性。MS-Ep比MS具有更好的亲水性，但吸水后孔结构保持稳定。MOS-Ey是相当疏水的，并且表现出去 ...更多信息 3.氧化形成的酸中心：氧化处理使MOS-SH表面的巯基转化为磺酸基（-SO_3H）。4.在有机合成中的应用：我们发现不对称2，6-二（恶唑啉基）吡啶（pybox）/钌催化剂被吸附在硅胶（如MS和MS-NH 2）上，并作为固载催化剂用于催化不对称环丙烷化反应。对于重氮酯和烯烃的催化不对称环丙烷化反应，在Pybox/Ru（II）催化剂上，在水相和两相体系中都成功地进行了反应，得到了相应的环丙酯，沿着大于95%.此外，在333 K下，在没有CuI等助催化剂的情况下，单恶唑啉苯基（phemox）/钯（Pd/MOS-Py）配合物催化碘代硝基苯和乙炔苯衍生物的Sonogashira偶联反应。以MOS-Py为载体的phemox/Pd催化剂的催化效率与未负载的催化剂几乎相同。少

Mesoporous silicas(MS) with uniform pore structure were successfully prepared. Chemical active groups such as aminopropyl, octyl, and epoxycyclohexyl groups were anchored on MS surfaces, designated as MS-NH2,MS-C8 and MS-ep, respectively. Mesoporous organosilicas including ethytene chains, aminopropyl, thiol and pyridinium groups in the framework structures were also obtained (abbreviated as MOS-Ey,MOS-NH2,MOS-SH and MOS-Py, respectively). The following researches were performed by use of these samples.1.Acetaldehyde adsorption on MS-NH2 : The sorptivity of acetaldehyde was drastically improved by the anchoring of aminopropyl groups. Especially, the sorptivity at low concentration increased in MS-NH2 with narrower pore sizes of ca. 1 nm.2.Surface stability and hydrophobe/hydrophile control : MS-C8 exhibited hydrophobic character. MS-Ep showed more hydrophilic character than MS, while the pore structure stably retained after water sorption. MOS-Ey was rather hydrophobic and exhibited go … More od sorptivity for alkane vapor.3.Acid sites formation by oxidation of MOS-SH : Thiol groups on MOS-SH surface were converted to sulfonic acid ones (-SO_3H) by an oxidation treatment. Solid acidity of the MOS-SO_3H characterized by ammonia adsorption microcalorimetry was comparable to that of aluminosilicate zeolites.4.Application to organic synthesis : We found that asymmetric 2,6-bis(oxazolinyl)pyridine(pybox)/ruthenium catalyst was adsorbed on silica such as MS and MS-NH2 and acted as solid-supported catalyst for a catalytic asymmetric cyclopropanation reaction. In the case of catalytic asymmetric cyclopropanation reactions of diazoester and alkenes, the reaction was successfully proceeded with pybox/Ru(II) catalyst in both water phase and two phases to give the corresponding cyclopropylesters along with over 95% enantioselectivities. Furthermore, monooxazolinylphenyl (phemox)/palladium complexes supported on MOS-Py catalyzed Sonogashira coupling reactions of iodonitrobenzene and ethynybenzene derivatives at 333K without any other co-catalysts such as CuI. The efficiency of phemox/Pd catalyst supported on MOS-Py was almost same as the non-supported catalyst. Less