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.
The title complex 1.THF has been synthesized by the reaction of [HO-4,6-di-^tBu- C6H2-2-CH2{CH（IPrNCHCHN）}]C1 with NdCl3 in a 2：1 molar ratio in THF, and characterized by single-crystal X-ray diffraction. It crystallizes in monoclinic, space group P2dc with a = 9.6501 （14）, b = 16.393（2）, c = 36.745（6） ]A, β = 97.444（4）^o, V= 5763.7（15） ]A^3, Mr= 1124.69, Z = 4, Dc= 1.296 g/cm^3, μ（MoKa） = 1.175 mm-1, F（000） = 2348, the final R = 0.0729 and wR = 0.1762 for 8735 observed reflections with 1 〉 2σ（I）. Complex 1 consists of an anion [NdC15（THF）]^2- and two cations [HO-4,6-di-tBu-C6H2-2-CH2{CH（iprNCHCHN）}]2^＋ to form a layer structure by the interconnection of anions and cations via hydrogen bonding. The central metal Nd in the anionic unit is coordinated by five C1 atoms and one oxygen atom from solvated THF molecule assuming a distorted octahedral geometry.
Reaction of homoleptic yttrium tris-alkyl complex YR3 (R=CH2C6H4NMe2-o) with 1 equivalent of amine bis(phenol)s LH2 (L=Me2NCH2CH2N(CH2-(2-O-C6H2-But2-3,5))2) afforded the solvent-free yttrium alkyl complex LYR (1),which has been characterized with elemental analysis,1H NMR and IR spectra,and structural determination. The coordination geometry around the center metal atom can be best de-scribed as a distorted octahedron. It was found that complex 1 can be used as an efficient catalyst for the Tishchenko reaction.
