motifs in organocatalysis, whereas efficient 1,3‐diamine‐derived organocatalysts are very rare. Herein we report a highly efficient camphor‐1,3‐diamine‐derived squaramideorganocatalyst. Its catalytic activity in Michaeladditions of 1,3‐dicarbonyl nucleophiles to trans‐β‐nitrostyrene derivatives provides excellent enantioselectivities (up to >99% ee).
Tertiary Amine-Derived Ionic Liquid-Supported Squaramide as a Recyclable Organocatalyst for Noncovalent “On Water” Catalysis
作者:Rinat S. Tukhvatshin、Alexander S. Kucherenko、Yulia V. Nelyubina、Sergei G. Zlotin
DOI:10.1021/acscatal.7b00562
日期:2017.4.7
was synthesized from available precursors and applied as an efficient organocatalyst for asymmetricMichael additions of β-dicarbonyl compounds to α-nitroolefins in the presence of water. Corresponding Michael adducts were generated under proposed conditions in nearly quantitative yield with high enantioselectivity (up to 99% ee). Useful precursors to pharmaceutically important chiral β-amino acids and
Chiral Squaramide-Functionalized Imidazolium-Based Organic–Inorganic Hybrid Silica Promotes Asymmetric Michael Addition of 1,3-Dicarbonyls to Nitroalkenes in Brine
作者:Xiangming Xu、Tanyu Cheng、Xiaochen Liu、Jianyou Xu、Ronghua Jin、Guohua Liu
DOI:10.1021/cs5002459
日期:2014.7.3
cinchona-based squaramide active center is incorporated onto the organic–inorganic hybrid silica. As a bifunctional heterogeneous catalyst, it displays excellent catalytic activity and high enantioselectivity in asymmetric Michael addition of 1,3-dicarbonyl compounds to nitroalkenes in brine. As presented in this study, the synergistic effect of confined site-isolated squaramide species and a salient imidazolium
Novel and highly efficient bifunctional calixarene thiourea derivatives as organocatalysts for enantioselective Michael reaction of nitroolefins with diketones
作者:Hayriye Nevin Genc、Abdulkadir Sirit
DOI:10.1007/s10847-017-0761-1
日期:2018.2
New bifunctional calixarene thiourea organocatalysts were synthesized and applied in catalytic asymmetric Michael addition of acetylacetone to various nitroolefins at room temperature. The corresponding adducts were obtained in good to excellent yields with excellent enantioselectivities (up to 92% ee). The present research demonstrates the advantages of incorporating two stereocontrolling structures
The chiral squaramide derivatives as hydrogen bonding catalyst for the Michael addition reactions of 1,3-dicarbonyl compounds to nitroolefins under solvent-free conditions was developed using a planetary ball mill. High yields, high enantioselectivities and shorter reaction times were achieved with lowcatalystloading.