5-Aminopyrazole-4-carbonitrile and ethyl 5-aminopyrazole-4-carboxylate, as potential trifunctional building blocks are introduced in a facile, chemo- and regioselective multicomponent assembly of imidazo[1,2-b]pyrazoles via the Groebke-Blackburn-Bienaymé reaction (GBB reaction). Besides the synthetic elaboration of a green-compatible isocyanide-based access in three-component mode, we describe ...

Abstract The reactions of [Fe2Cp2(CO)4] with a series isocyanides, CNR, were conducted in acetonitrile and afforded, after thermal treatment, the mono-isocyanide derivatives [Fe2Cp2(CO)3(CNR)] [R = 1H-indol-5-yl, 1; CH2P(O)(OEt)2, 2; Cy = C6H11, 3; 4-C6H4OMe, 4; Xyl = 2,6-C6H3Me2, 5; Me, 6; 2-naphthyl, 7; Bn = CH2Ph, 8]. In order to avoid multiple substitution, diiron reactant was used molar ex...

Poly(isocyanidcs), ( R N = C < ) n, can be prepared from isocyanidcs, R N += C " , by the catalytic action of nickel(II) compounds. The main chain of these polymers is a rigid helix. This helical conformation results from a restricted rotation around the single bonds that connect the main-chain carbon atoms. Polymerization of achiral isocyanides generally gives a racemic mixture of leftand righ...

The new binuclear chromium Pacman complex [Cr2(L)] of the Schiff base pyrrole macrocycle H4L has been synthesized and structurally characterized. Addition of isocyanide, C≡NR (R = xylyl, tBu), or triphenylphosphine oxide donors to [Cr2(L)] gives contrasting chemistry with the formation of the new coordination compounds [Cr2(μ-CNR)(L)], in which the isocyanides bridge the two Cr(II) centers, and...

The structure of the active complex in the Ni-catalyzed polymerization of isocyanides to give polyisocyanides is investigated. It is shown by X-ray absorption spectroscopy (XAS), including EXAFS (extended X-ray absorption fine structure) and XANES (X-ray absorption near edge structure), and single-crystal X-ray diffraction, to contain a carbene-like ligand. This is the first structural characte...

The treatment of cis-[PtCl2(XylNC)2] with thiazol-2-amines in a 2:1 ratio leads to regioisomeric mixture two binuclear complexes. These regioisomers are products kinetic and thermodynamic control capable regioisomerization. When the same reaction is carried out 5-fold excess thiazol-2-amine, nucleophile able react situ-formed platinum(II) complexes, yielding new type bis-carbene platinum specie...

The methyl–amide complex [TaCp*(NBu)Me(NMe2)] (1a) was isolated by reaction of the chloro–methyl [TaCp*(NBu)MeCl] complex with LiNMe2. Reaction of the mono-amide compounds [TaCp*(N Bu)XY] (X=NMe2, Y=Me (1a); X=NHBu, Y=Me (1b), Cl (1c)) with CO2 gives the h-carbamate derivatives [TaCp*(NBu)(h-O2CX)Y] (X=NMe2, Y=Me (2a); X=NHBu, Y=Me (2b), Cl (2c)). A similar reaction with the di-amide complex [T...