Key Laboratory for Advanced Materials and Institute of Fine Chemicals, East China University of Science and Technology, 130 Mei Long Road, Shanghai 200237, China.
Department of Chemistry, East China Normal University, 3663 N. Zhongshan Road, Shanghai, 200062, China.
Org Biomol Chem. 2018 Jul 7;16(25):4641-4649. doi: 10.1039/c8ob01090k. Epub 2018 Jun 14.
We have developed an efficient diastereo- and enantioselective Mannich/cyclization cascade reaction of α-substituted isocyanoacetates with 4-aryl-3-carbonyl-1,2,5-thiadiazole-1,1-dioxide type cyclic sulfamide ketimines cooperatively catalyzed by cinchona alkaloid-derived squaramide and AgOAc. The corresponding optically active 2,3,3a,4-tetrahydroimidazo[1,5-b][1,2,5]thiadiazole-1,1-dioxide derivatives were obtained in excellent yields (up to 99%) and good to excellent stereoselectivities (up to >20 : 1 dr, up to 94% ee).
我们开发了一种高效的非对映选择性和对映选择性曼尼希/环化级联反应，反应中α-取代异氰基乙酸酯与 4-芳基-3-羰基-1,2,5-噻二唑-1,1-二氧化物型环亚磺酰胺酮亚胺在奎纳生物碱衍生的螺二酰胺和 AgOAc 的协同催化下发生反应。相应的光学活性 2,3,3a,4-四氢咪唑并[1,5-b][1,2,5]噻二唑-1,1-二氧化物衍生物以优异的收率（高达 99%）和良好到优异的立体选择性（高达>20:1 dr，高达 94%ee）获得。
