Jian‐Guo Yang

Phosphine/palladium-catalyzed one-pot synthesis of functionalized 6H-benzo[c]chromenes

In this study, a one-pot, phosphine/palladium sequential catalysis reaction has been realized, and a series of functionalized alkenyl 6H-benzo[c]chromenes are synthesized in high yields and with good stereoselectivity.

Vinylogous elimination/Heck coupling/allylation domino reactions: access to 2-substituted 2,3-dihydrobenzofurans and indolines

A highly regio- and stereoselctive palladium-catalyzed domino reaction of functionalized aryl allyl ethers has been developed. Various aryl allyl ethers derived from the phosphine-catalyzed addition of electron-deficient allenes with phenol are found to be efficient substrates for the synthesis of 2-substituted 2,3-dihydrobenzofurans and indolines. It is the first example of aryl allyl ether used as an ideal and practical precursor of hard to get functionalized 1,3-butadiene for the heterocyclic compound synthesis.

[4 + 2] Annulation of 3-Nitroindoles with Alkylidene Malononitriles: Entry to Substituted Carbazol-4-amine Derivatives

A general and transition-metal-free method for the construction of the carbazol-4-amine motif via a vinylogous Michael addition/cyclization/isomerization/elimination reaction of 3-nitroindoles with alkylidene malononitriles has been developed. This novel methodology allows the facile synthesis of a series of di- and trisubstituted carbazol-4-amine derivatives in moderate to good yields. A gram-scale experiment was successfully performed, highlighting the practicability of this method. Moreover, this strategy is also applicable to 3-nitrobenzothiophene, affording the corresponding dibenzo[ b, d]thiophen-1-amine derivatives in moderate yields.

Synthesis and crystal structure of Ni(II) complexes of 2′-(3,5-dibromo-2-hydroxybenzylidene)-3,5-dihydroxybenzoylhydrazide

A new mononuclear nickel(II) complex incorporating a Schiff-base ligand, [NiL2](DMF)4 (HL = 2′-(3,5-dibromo-2-hydroxybenzylidene)-3,5-dihydroxybenzoylhydrazide), has been synthesized and characterized by IR, UV-Vis, elemental analysis and X-ray crystal structure analysis. HL is an anionic tridentate ligand. The nickel atom is hexacoordinated with two oxygen atoms from keto group and two oxygen atoms from hydroxy group and two nitrogen atoms from amide, with the two nitrogen atoms occupying the axial positions forming a distorted octahedral coordination sphere.

Synthesis and structure of a trimeric copper(II) complex of N ′-[(1Z)-1H-1,2,4-triazol-3-ylmethylene]- 1 H -1,2,4-triazole-3-carbohydrazide

The complex [Cu3L2Cl4](H2O)6 (HL = N′-[(1Z)-1H-1,2,4-triazol-3-ylmethylene]-1H-1,2,4-triazole-3-carbohydrazide) has been synthesized and characterized by IR, elemental analysis and X-ray crystal structure analysis. Crystal data: triclinic, P , a = 7.8591(12), b = 9.6745(14), c = 9.8798(15) Å, α = 83.301(3), β = 71.602(3), γ = 80.531(3)°, V = 701.40(18) Å3, Z = 1, D c = 2.014 Mg m−3, μ = 2.706 mm−1, F(000) = 425, R 1 = 0.0447, wR 2 = 0.1133 (I ≥ 2σ(I )), S = 1.001. The crystal structure contains [Cu3L2Cl4] trimers combining coordination and hydrogen bonding interactions. The geometries of the Cu(II) ions differ. The terminal Cu(II) ions have distorted square pyramidal geometry and are surrounded by two chloride anions and one deprotonated ligand. The central Cu(II) is square planar, bonded to one imino nitrogen atom and one carbonyl oxygen atom of each ligand.

Bis­[4-phenyl-5-(1H-1,2,4-triazol-3-yl)-4H-1,2,4-triazol-3-yl] di­sulfide

The title compound, C20H14N12S2, was synthesized by the reaction of 3-hydrazino-1H-1,2,4-triazole with phenyl isocyanate in benzene and by ring closure in an alkaline medium. Intermolecular N—H⋯N hydrogen bonds are observed and these form a five-membered ring.