Research on Asymmetric Reaction with New Chiral Schiff Base-Metal Cpmplexes

我已经发明了许多使用手性席夫碱金属络合物作为催化剂的新的催化对映选择性反应。其中之一是三甲基氰化物与醛的不对称加成反应，得到光学活性大于90%的氰醇。本项目的研究是利用手性希夫碱进行的一些新的不对称催化反应。第一种是双乙烯酮与醛的不对称加成反应，得到手性的5-羟基-3-酮酯。本发明的某些产品可用于合成降低血液中总胆固醇的新药。使用10MO1%的手性钛催化剂，定量化学产率可达90%以上。第二个研究是对称环氧化物的不对称开环芳基化反应。在反应介质中，以手性席夫碱的烷氧基锂为催化剂，可得到ee大于90%的开环产物。产物很容易重结晶，得到光学纯净的化合物。此外，反式-2-芳基环己醇是制备多种药物的非常有用的手性前体。这一发明被申请为专利。

I already invented many new catalytic enantioselective reactions using chiral schiff base-metal complexes as catalyst. One of them was enantioselective addition of trimethylcyanide to aldehydes to give highly optically active cyanohydrins over 90% ee.The investigations by this project were new some enantioselective catalysis using chiral schiff bases. The first was the enantioselective addition of diketene to aldehydes to give chiral 5-hydroxy-3-ketoesters. Some kind of the products can be applied for the synthesis of new medicine lowering colesteroles in blood. The use of 10 mo1% of chiral titanium catalyst afforded over 90% ee's product in quantitative chemical yield.The second research was the enantioselective ring opening arylation of symmetrical epoxides such as cyclohexene oxide. Lithium alokoxide of chiral schiff bases in reaction media acts as catalyst to give ring opening product having over 90% ee. The products easily were recrystallized to give optically pure compounds. Also trans-2-arylcyclohexanols are very useful chiral precursors to prepare a variety of medicines. This invension was applied as a patent.