Developing chiral solid catalysts for asymmetric catalysis is desirable for the elimination of homogeneous catalysis flaws but remains an immense challenge.Herein,we report the immobilization of TsDPEN on SBA‐15 with...Developing chiral solid catalysts for asymmetric catalysis is desirable for the elimination of homogeneous catalysis flaws but remains an immense challenge.Herein,we report the immobilization of TsDPEN on SBA‐15 with an ionic liquid(IL)linkage via the one‐pot reaction of imidazole‐TsDPEN‐N‐Boc with 3‐(trimethoxysilyl)propyl bromide in the SBA‐15 mesopores.After coordination to Rh,the chiral solid catalysts could efficiently catalyze quinoline transfer hydrogenation,achieving 97%conversion with 93%ee,which was comparable to their homogeneous counterparts.The chiral solid catalyst with the IL linkage afforded much higher turnover frequency than that without the IL linkage(93 h^(–1)vs.33 h^(–1)),attributed to the phase transfer and formate‐enriching ability of the IL linkage.Furthermore,the effect of the pH on the reaction rate of the solid catalyst was investigated,preventing reaction rate retardation during the catalytic process.The tuning of the linkage group is an efficient approach for catalytic activity improvement of immobilized chiral catalysts.展开更多
The crystal and molecular structure of diethyl l-(p-toluenesulfon-amido ) - p chlofoPhenylmet hylphosphonate has been determined by X- ray d iffractionmethod- The crystal (C18,H23,ClNO5PS) is monoclinic with space gro...The crystal and molecular structure of diethyl l-(p-toluenesulfon-amido ) - p chlofoPhenylmet hylphosphonate has been determined by X- ray d iffractionmethod- The crystal (C18,H23,ClNO5PS) is monoclinic with space group P21/c, a =8. 162(6), b= l8. O64(7), c= l4. 362(4) A, β=96. 29(3)°, V=2lO4. 7 A3, M.=431, 88, Z=4, Dx= l. 364 g/cm3, μ, = 3. 765 cm-1, F(000) = 904, R=0. 047 andRw=0. 0049 for 998 reflections with I>3σ(I). The 1H NMR spetrum of the title com-pound shows that the two ethoxy groups are magnetic nonequivalent, which is in agree-ment with its X-ray analysis result-展开更多
文摘Developing chiral solid catalysts for asymmetric catalysis is desirable for the elimination of homogeneous catalysis flaws but remains an immense challenge.Herein,we report the immobilization of TsDPEN on SBA‐15 with an ionic liquid(IL)linkage via the one‐pot reaction of imidazole‐TsDPEN‐N‐Boc with 3‐(trimethoxysilyl)propyl bromide in the SBA‐15 mesopores.After coordination to Rh,the chiral solid catalysts could efficiently catalyze quinoline transfer hydrogenation,achieving 97%conversion with 93%ee,which was comparable to their homogeneous counterparts.The chiral solid catalyst with the IL linkage afforded much higher turnover frequency than that without the IL linkage(93 h^(–1)vs.33 h^(–1)),attributed to the phase transfer and formate‐enriching ability of the IL linkage.Furthermore,the effect of the pH on the reaction rate of the solid catalyst was investigated,preventing reaction rate retardation during the catalytic process.The tuning of the linkage group is an efficient approach for catalytic activity improvement of immobilized chiral catalysts.
文摘The crystal and molecular structure of diethyl l-(p-toluenesulfon-amido ) - p chlofoPhenylmet hylphosphonate has been determined by X- ray d iffractionmethod- The crystal (C18,H23,ClNO5PS) is monoclinic with space group P21/c, a =8. 162(6), b= l8. O64(7), c= l4. 362(4) A, β=96. 29(3)°, V=2lO4. 7 A3, M.=431, 88, Z=4, Dx= l. 364 g/cm3, μ, = 3. 765 cm-1, F(000) = 904, R=0. 047 andRw=0. 0049 for 998 reflections with I>3σ(I). The 1H NMR spetrum of the title com-pound shows that the two ethoxy groups are magnetic nonequivalent, which is in agree-ment with its X-ray analysis result-
