Qi Shen

Addition of Amines to Nitriles Catalyzed by Ytterbium Amides: An Efficient One-Step Synthesis of Monosubstituted N-Arylamidines

A one-step synthesis of monosubstituted N-arylamidinates via addition of amines to nitriles catalyzed by ytterbium amides is reported. The reactions with various substrates give the products in good to excellent yields with 5 mol % ytterbium at 100 degrees C under solvent-free conditions.

Tandem Michael addition/ylide epoxidation for the synthesis of highly functionalized cyclohexadiene epoxide derivatives

A highly efficient diastereoselective synthesis of cyclohexadiene epoxide derivatives with a multi-stereocenter has been developed via a tandem ylide Michael addition/epoxidation. By employing a chiral sulfonium ylide, up to 96% ee can be achieved in good yields.

One-pot highly diastereoselective synthesis of cis-vinylaziridines via the sulfur ylide-mediated aziridination and palladium(0)-catalyzed isomerization.

Highly diastereoselective synthesis of cis-trisubstituted vinylaziridines containing a quaternary carbon center is realized by a one-pot protocol in which the combination of sulfur ylide-mediated aziridination of cyclic ketimines and Pd(0)-catalyzed isomerization is employed successfully.

Multistep one-pot Wittig/Nazarov reaction for construction of cyclopentenone with diazo compounds and acid chlorides.

A facile multistep one-pot synthesis of single or fused cyclopentenones has been developed. The sequence involves a transition metal-catalyzed ylide formation/Wittig Olefination/Nazarov Cyclization.

Synthesis, structure, and ethylene polymerization behavior of nickel complexes based on benzoylmethylenetri(2-alkoxylphenyl)phosphorane

Several new nickel complexes are prepared by the treatment of the stabilized ylide benzoylmethylenetri(2-alkoxylphenyl)phosphorane with Ni(cod)(2) in the presence of PPh(3). X-Ray diffraction studies reveal that a distorted square planar geometry around Ni(II) is adopted. Upon treatment with Ni(cod)(2), the nickel complexes are sufficiently robust for ethylene polymerization. The existence of 2-alkoxyl-aryl substituents on phosphorus improves the catalytic activities. The highest activity (2.1 × 10(6) g mol(-1) h(-1)) is achieved when tri(2-isopropoxy-phenyl)phosphorane is employed (5e), which is one order higher than the corresponding SHOP catalyst. NMR analysis shows that the polyethylene mainly contains terminal double bonds and is highly linear.