Research on the production of new type of cyclic carbonates by using organomaignroup metal-compounds as high active catalysts

该项目旨在以工业上实际的反应速率从氧环烷和二氧化碳中生产各种碳酸盐。为此，我们开发了新型有机金属基催化剂；R_3 SnI-Lewis碱，R_2 sn_2 -碘化铵，PH_4 SBI等。这些催化体系具有以下优点：(1)催化活性高；二氧化碳和氧环烷的环加成在非常温和的条件下进行，如室温和较低的二氧化碳压力。活性较低的氧环烷，如2,3-二甲基氧环烷，很容易与二氧化碳反应，生成高收率的碳酸盐。(2)中立;这些催化剂几乎是中性的，因此适用范围很广。特别值得注意的是，锡配合物的酸度明显低于未配合的有机卤化锡。(3)定向性;顺式氧环烷对顺式碳酸盐有很高的选择性，尽管伴随有氧环烷与相应酮的异构化。即使我们的新型催化剂也不能完全抑制这种异构化。

This project aims the production of various carbonates from oxiranes and carbon dioxide at industrially practical reaction-rate. For this aim, we have developed novel organomaingrroup-metallic catalyst; R_3 SnI-Lewis bases, R_2 SnI_2 -onium iodides, PH_4 SBI, so on. These catalytic cystems have some advanitages as follows.(1) High catalystic activity; the cycloaddition of carbon dioxide and oxiranes proceeds under very mild conditions such as room temperature and lower pressure of carbon dioxide. Less reactive oxiranes such as 2,3-dimethyloxirance readily react with carbon dioxide to give carbonates in high yield.(2) Neutrality; these catalysts are so nearly neutral that wide range of oxiranes area appliciable. Particularyly, it is noteworthy that the acidity of the tin complexes is considerably lower than one of non-complexed organotin halides.(3) Stereospecificity; cis oxiranes gave cis carbonates in high selectivity, although the isomerization of oxiranes to corresponding ketones are accompanied. This isomerization could not be depressed completely even by our novel catgalyst.