The ytterbium chloride catalyzed Diels-Alder reaction of acrylate with furan was studied.The influence of reaction conditions upon the yield and stereoselectivity of the products was discussed emphatically.
YbCl3(C4H8O)3, Mr = 495. 73, monoclinic, space group P21/c, a = 9.024(2), b=12.863(2), c=15. 762(7) A ,β=92. 21(2)°. V = 1828. 7(9) A3, Z = 4, DC=1. 801gcm-3, A(MoKa) = 0. 71073A, μ= 64. 44cm-1, F (000) = 964, ...YbCl3(C4H8O)3, Mr = 495. 73, monoclinic, space group P21/c, a = 9.024(2), b=12.863(2), c=15. 762(7) A ,β=92. 21(2)°. V = 1828. 7(9) A3, Z = 4, DC=1. 801gcm-3, A(MoKa) = 0. 71073A, μ= 64. 44cm-1, F (000) = 964, R = 0. 075 for 2259 unique observed reflections. The Yb3+ ion is in a distorted octahedral coordination with three Cl ions and three O atoms from three tetrahydrofuran (THF) molecules. The average Yb -Cl distance is 2. 525A and Yb -O is 2. 303A.展开更多
The reaction of anhydrous YbCl3 with lithium b-diketiminate, LLi (L = N,N- diphenyl-2,4-pentanediimine anion), in 1:1 molar ratio in THF gave rise to the title complex LYbCl2(THF)2 1 which has been characterized by si...The reaction of anhydrous YbCl3 with lithium b-diketiminate, LLi (L = N,N- diphenyl-2,4-pentanediimine anion), in 1:1 molar ratio in THF gave rise to the title complex LYbCl2(THF)2 1 which has been characterized by single-crystal X-ray diffraction. It crystallizes in the orthorhombic system, space group Pna21(#33) with a = 19.657(8), b = 9.581(4), c = 14.107(6) ? V = 2656.8(18) 3, Z = 4, C25H33N2O2Cl2Yb, Mr = 637.49, Dc = 1.594 g/cm3, F(000) = 1268.00 and m(MoKa) = 3.744mm-1. The final R and wR are 0.031 and 0.073 for 2596 observed reflections with I > 2s(I), respectively. The X-ray crystal structure analysis revealed that the center ytterbium(III) is bonded to two chloride anions, two oxygen atoms from two tetrahydrofuran molecules and one chelate ligand b-diketiminate to form a six-coordinate distorted octahedral geometry.展开更多
A clean,efficient method to synthesize 2-amino-4H-3,1-benzothiazines by ytterbium chloride-catalyzed tandem addition-cyclization reaction of o-aminocinnamate and isothiocyanates under solvent-free conditions is develo...A clean,efficient method to synthesize 2-amino-4H-3,1-benzothiazines by ytterbium chloride-catalyzed tandem addition-cyclization reaction of o-aminocinnamate and isothiocyanates under solvent-free conditions is developed.展开更多
文摘The ytterbium chloride catalyzed Diels-Alder reaction of acrylate with furan was studied.The influence of reaction conditions upon the yield and stereoselectivity of the products was discussed emphatically.
文摘YbCl3(C4H8O)3, Mr = 495. 73, monoclinic, space group P21/c, a = 9.024(2), b=12.863(2), c=15. 762(7) A ,β=92. 21(2)°. V = 1828. 7(9) A3, Z = 4, DC=1. 801gcm-3, A(MoKa) = 0. 71073A, μ= 64. 44cm-1, F (000) = 964, R = 0. 075 for 2259 unique observed reflections. The Yb3+ ion is in a distorted octahedral coordination with three Cl ions and three O atoms from three tetrahydrofuran (THF) molecules. The average Yb -Cl distance is 2. 525A and Yb -O is 2. 303A.
基金Supported by the National Natural Science Foundation of China (20072027) Department of Education of Jiangsu province and the Key Laboratory of Organic Synthesis of Jiangsu province
文摘The reaction of anhydrous YbCl3 with lithium b-diketiminate, LLi (L = N,N- diphenyl-2,4-pentanediimine anion), in 1:1 molar ratio in THF gave rise to the title complex LYbCl2(THF)2 1 which has been characterized by single-crystal X-ray diffraction. It crystallizes in the orthorhombic system, space group Pna21(#33) with a = 19.657(8), b = 9.581(4), c = 14.107(6) ? V = 2656.8(18) 3, Z = 4, C25H33N2O2Cl2Yb, Mr = 637.49, Dc = 1.594 g/cm3, F(000) = 1268.00 and m(MoKa) = 3.744mm-1. The final R and wR are 0.031 and 0.073 for 2596 observed reflections with I > 2s(I), respectively. The X-ray crystal structure analysis revealed that the center ytterbium(III) is bonded to two chloride anions, two oxygen atoms from two tetrahydrofuran molecules and one chelate ligand b-diketiminate to form a six-coordinate distorted octahedral geometry.
基金supported by the National Natural Science Foundation of China(20872106,20972107)the Priority Academic Program Development of Jiangsu Higher Education Institutions
文摘A clean,efficient method to synthesize 2-amino-4H-3,1-benzothiazines by ytterbium chloride-catalyzed tandem addition-cyclization reaction of o-aminocinnamate and isothiocyanates under solvent-free conditions is developed.
