| Asymmetric organic small molecule catalysis is an important part of asymmetric synthesis and plays a major role in organic chemistry.It is widely used in the synthesis and development of chiral drugs,chemical production and biochemistry due to its high stereosel ectivity,good air and water stability and the absence of metal ions.The synthesis of axial chiral ligands and catalysts has been one of the hotspots in the field of asymmetric catalysis in recent years.Such compounds have important reference value for researchers in related fields such as pharmaceutical synthesis chemistry and asymmetric catalysis.The C2-axis chiral naphthol(BINOL)skeleton is an important structural unit of the chiral chiral ligand and catalyst,and various types of ligands and catalysts can be obtained by appropriately modifying the structure.Chiral thiourea is a commonly used multi-hydrogen bond donor type catalyst,which can activate the reaction reagent by forming a hydrogen bond with the substrate to further catalyze the reaction,and plays a major role in asymmetricsyn thesis.1.Based on the literature and the research of this research group,more than ten BINOL polyhydrogen bond thiourea catalysts were synthesized and used to catalyze the synthesis of tetrahydrothiophene derivatives by asymmetric Sulfa-Michael/Aldol series reaction.Optimized.Studies have shown that the optimum conditions for the reaction are 20 mmol% catalyst,THF as solvent(2 mL),reaction temperature 25 ℃,KF as additive(6 mmol%),and the reaction can be carried out efficiently.2.Under the optimal conditions,the reaction substrate was expanded.The results showed that the chiral BINOL polyhydrogen thiourea small molecule catalyst synthesized in this paper can effectively catalyze the Sulfa-Michael/Aldol reaction with higher yield(95%),excellent enantioselectivity(97%)and diastereoselectivity(>94:6 dr)gave a spirotetrahydrothiophene derivative.All products were characterized by NMR,IR,MS,and the like. |
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