论文部分内容阅读
首次采用 4 烷氧羰基噻唑烷、唑烷作为手性配体 ,诱导烷基锌对醛类的亲核加成反应 ,获得产物是烷基化的醛 ,最高达 90 %ee ,产率 98%的 (S) 二级醇。系统地考察了该类手性配体三维空间结构变化与产物对映选择性的关系 ,当配体 4 位烷氧羰基上的R、2 位R′基和环体上原子X发生变化时都会引起产物 (S) 二级醇的对映选择性发生规律性变化。对五种不同结构的底物醛在同一手性配体催化下 ,诱导烷基锌对醛类的亲核加成反应 ,底物结构变化也会引起 (S) 二级醇对映选择性变化
For the first time, 4-alkoxycarbonylthiazolidine and oxazolidine were used as chiral ligands to induce the nucleophilic addition of alkylzinc to aldehydes to obtain alkylated aldehydes up to 90% ee with a yield of 98 % Of (S) secondary alcohol. The relationship between the three-dimensional structure of the chiral ligands and the enantioselectivity of the products was systematically investigated. When the R, 2-position R ’groups on the 4-position alkoxycarbonyl group of the ligand and the atom X on the ring body changed Causing the enantioselectivity of the secondary alcohol of (S) to change regularly. The five aldehydes with different structures were catalyzed by the same chiral ligand to induce the nucleophilic addition reaction of alkylzinc to aldehydes. The change of substrate structure also caused the enantioselective change of (S)