Synthesis of novel norephedrine-based chiral ligands with multiple stereogenic centers and their application in enantioselective addition of diethylzinc to aldehyde and chalcone

Novel norephedrine-based chiral ligands with multiple stereogenic centers were conveniently prepared from norephedrine and N-substituted pyrrole. These novel chiral ligands were used to catalyze the enantioselective addition of diethylzinc to aldehydes and to chalcone in high yields and with good to high enantioselectivities. The absolute configuration of products was found to be affected by the stereogenic centers on the norephedrine part of the novel chiral ligands

Metal triflates-catalyzed conjugate addition of homochiral Pyrroles to alpha,beta-unsaturated esters

The Friedel-Crafts reaction of homochiral pyrrole derivatives with alpha,beta-unsaturated esters catalyzed by metal triflates furnished conjugate addition products. The best yields were obtained by using yttrium triflate and methyl 4-phenyl-2-oxobut-3-enoate (2a). The addition worked regioselectively at C-5 of pyrrole. The diastereoisomers were separated by column chromatography

Cerium 3,5-Dinitrobenzoate Dihydrate

In the crystal structure of the title molecule, catena-poly[[tetraaqua-1 kappa(2) O,2 kappa(2)O-tetrakis(mu-3, 5-dinitrobenzoato-O:O') dicerium]-bis(mu-3,5-dinitrobenzoato-O:O')], [Ce-2(C7H3N2O6)(6)(H2O)(4)], cerium ions are bridged by carboxylate groups to form linear polymeric chains. The coordination around Ce is eightfold involving six O atoms from six carboxylate groups and two water O atoms. Within the polymeric chains, only the bridging type of bonding exists. Ce-O distances vary between 2.400 (5) and 2.661 (5) Angstrom, resulting in a strongly distorted square-antiprism arrangement around Ce.WoSScopu

N,N,N ',N '-tetramethylethylenediammonium dichloride

kabak, mehmet/0000-0001-6097-9394WOS: 000086645900070The structure of the title compound, C6H18N22+. 2Cl(-), has been determined and has a centre of symmetry, The molecule has strong intermolecular hydrogen bonding between each Cl- and an N-H bond [Cl ... N = 3.012 (3) Angstrom]