An efficient chemoselective synthesis of O-vinylaryl systems using acetylenic esters and dihydroxybenzenes in the presence of triphenylphosphine or alkyl isocyanides

The addition of 2,4-dihydroxyaceto(and benzo)phenone to propiolic ester is catalyzed by triphenylphosphine or tert-butyl isocyanide to form O-vinyl aryl derivatives in fairly good yields.

Synthesis of 4H-chromene derivatives by reaction between alkyl isocyanides and dialkyl acetylenedicarboxylate in the presence of 6-hydroxyquinoline

The reactive intermediate generated by the addition of alkyl isocyanides to dialkyl acetylenedicarboxylate was trapped by 6- quinolinol to produce highlyfunctionalized 4H-chromenes in fairly good yields.

Three-component reaction of alkyl isocyanides with acetylenic esters and pyridine-2-carboxaldoxime or α-furildioxime:Synthesis and dynamic NMR study of ketenimines and bis(ketenimines)

The addition of pyridine-2-carboxaldoxime or α-furildioxime to dialkyl acety lenedicarboxy lates under neutral conditions in the presence of alkyl isocyanides leads to ketenimines and bis（ketenimines） in good yields.

Palladium-catalyzed cyclization of 1-alkynyl-8-iodonaphthalene and double isocyanides for the synthesis of acenaphtho[1,2-b]pyrroles

A palladium-catalyzed formal[2+2+1]cyclization of 1-alkynyl-8-iodonaphthalene with double isocyanides is developed herein.The transformation worked well to produce a series of 7 H-acenaphtho[1,2-b]pyrrole with a broad reaction scope.Isocyanides play a dual role in the reaction.One is a C1 building block,and another is used as C1 N1 component.In the process,the[2+2+1]cyclization involves imidoylation,regioselective addition of imidoylpalladium species into alkyne,double imidoylation,and another addition of the resulting imidoylpalladium species into imine bonds.

Halogen effects on phenylethynyl palladium(Ⅱ) complexes for living polymerization of isocyanides

Polyisocyanides belong to one of the most important artificial helical polymers. The rigid-rod helical conformation makes them to exhibit wide potential applications in chiral recognition, enantioseparation, asymmetrical catalysis, and liquid crystals [1]. Up to now, quite a few metal-promoted polymerization methods have been developed to synthesize polyisocyanides. Especially, it is a great challenge for synthetic chemists to synthesize polyisocyanides in living/controllable fashion that afford well-defined and high isotactic helical polymers.

Synthesis of 2-Amino-1,3,4-oxadiazoles through Elemental Sulfur Promoted Cyclization of Hydrazides with Isocyanides

A novel sulfur-promoted cyclization of hydrazides and isonitriles to produce 1,3,4-oxadiazole has been devel- oped. The method is operationally simple and compatible with a wide scope of substrates and various 2-amino- 1,3,4-oxadiazoles are efficiently obtained in good yields.

Palladium-catalyzed concerted [4+1] cyclization of prop-2-yn-1-ones and isocyanides

A palladium-catalyzed [4+1] cycloaddition of prop-2-yn-1-ones with double isocyanides is developed herein.The transformation worked well to produce a series of 2-amino-4-cyanofurans with high efficiency and a broad reaction scope.Based on mechanism studies,it is believed that the palladiumcatalyzed [4+1] imidoylative cycloaddition of prop-2-yn-1-ones was concerted.Treated with a ryl amine and H_2 O,the [4+1] cycloaddition of prop-2-yn-1-ones with double isocyanides provided 2-amino-4-amidylpyrroles efficiently.

Palladium-Catalyzed Intermolecular Oxidative Coupling Reactions of （Z）-Enamines with Isocyanides through Selective β-C（sp2）-H and/or C = C Bond Cleavage

Herein, two efficient palladium-catalyzed intermolecular oxidative coupling reactions of （Z）-enamines with isocyanides via selective β-C（sp2）-H and/or C=C bond cleavage have been developed, leading to controllable chemodivergent and stereoselective construction of a wide range of （E）-β-carbamoylenamine derivatives containing strong intramolecular hydrogen bonds. Furthermore, possible reaction pathways for these transfor- mations are proposed on the basis of preliminary mechanism studies.

Facile Synthesis of 4-H-Pyran Derivatives Bearing Indole Skeleton via[3+3]Cyclization of 3-Indolyl-3-oxopro-panenitriles with Dialkyl Acetylenedicarboxylates and Isocyanides

An efficient multicomponent reaction of 3-indolyl-3-oxopropanenitriles with dialkyl acetylenedicarboxylates and isocyanides under mild conditions leading to highly functionalized 6-(indol-3-yl)-4H-pyrans in moderate to good yields has been developed.

Copper-catalyzed chemoselective heterocyclization of two isocyanides:Facile access to pyrroloazepinone derivatives

A Cu-catalyzed chemoselective heterocyclization of o-cinnamoyl arylisocyanides with α-substituted tosylmethyl isocyanides is developed for the efficient synthesis benzopyrroloazepinones. An isocyanide insertion into the C–Cu bond of organocuprate intermediate is involved for the formation of the sevenmembered azepinone ring.

Palladium-Catalyzed Cyclization Reaction of o-Haloanilines, CO2 and Isocyanides： Access to Quinazoline-2,4（1H,3H）-diones

Quinazoline-2,4（1H,3H）-diones are core structural subunits frequently found in many biologically important compounds. The reaction of 2- aminobenzonitrile and CO2, which was frequently studied, only provided N3-unsubstituted quinazoline-2,4（1H,3H）-dione compounds. Herein we report palladium-catalyzed cyclization reactions of o-haloanilines, CO2 and isocyanides to prepare N3-substituted quinazoline-2,4（1H,3H）-diones. Electron-rich o-bromoanilines participated in the cyclization reaction using Cs2CO3 at high temperature, and electron-deficient o-bromoaniline or o-iodoaniline sub- strates conducted the reaction using CsF as base to deliver corresponding quinazoline-2,4（1H,3H）-dione products in good yields.

Synthesis of functionalized azadienes from aminobenzothiazole,acetylenic esters and isocyanides

The reaction between 2-aminobenzothiazole with dialkyl acetylenedicarboxylates in the presence of isocyanides,leads to functionalized azadienes in good yields.

Catalyst-free formal[4+1]/[4+2]cyclization cascade sequence of isocyanides with two molecules of acylketene formed in situ from thermal-induced Wolff rearrangement of 2-diazo-1,3-diketones

An expedient and economic approach for constructing O,O,N-spiro compounds consisting of both a 1,3-oxazine and a furan ring through a catalyst-free formal[4+1]/[4+2]cycloaddition cascade sequence of isocyanides with two molecules of acylketene formed in situ through thermal-induced Wolff rearrangement of 2-diazo-1,3-diketones was developed.The reaction displayed good functional group tolerance and was compatible with different isocyanides and 2-diazo-1,3-diketones.Furthermore,preliminary asymmetric attempts of this reaction are made by utilizing optically pure isocyanides as inputs,and moderate diastereomeric induction was observed.

Mn(Ⅲ)-mediated radical cascade reaction of boronic acids with isocyanides:Synthesis of diimide derivatives

A manganese (Ⅲ)-promoted oxidative radical cascade reaction of easily accessible arylboronic acids with isocyanides to construct diimide derivatives was studied. This protocol provides a new way to synthesis of acetyl diimide derivatives. New C-C, C-N and C=O bonds were formed in one step.

Template Synthesis of CPP32 Inhibitors by Ugi Four-Component Condensation Reaction

To find a reasonable way to prepare the designed CPP32 inhibitors. Method Ugifour-component condensation reaction was used to synthesize peptide mimic CPP32 inhibitors; ResultsA key isocyanide component (aspartate-derived isocyanide 3) and one of the designed CPP32inhibitors 4 (as a template) were synthesized; Conclusion The CPP32 inhibitor 4 was synthesized bythe newly developed procedure, which is an Ugi four-component condensation reaction based onaspartate-derived isocyanide 3. This method can be used to build up the CPP32 inhibitor library.

Synthesis and Chemical Shifts Calculation of α-Acyloxycarboxamides Derived from Indane-1,2,3-trione by DFT and HF Methods

α-Acyloxycarboxamides are synthesized from three-component Passerini reaction between indane-1,2,3-trione, isocyanides, and thiophenecarboxylic acids in quantitative yields. The structures of the final products were confirmed by IR, 1H and 13C NMR spectroscopy, mass spectrometry, and elemental analysis. The B3LYP/HF calculations for computation of 1H and 13C NMR chemical shifts have been carried out for the title compounds at the 6-311＋G＊＊ and 6-311＋＋G＊＊ basis set levels within GIAO and CSGT approaches. Predicted 1H and 13C NMR che-mical shifts have been assigned and compared with experimental 1H and 13C NMR spectra and they are supported each other.

DFT Investigation on the Insertion Reaction of an Isocyanide into the(Silyl)(silylene)molybdenum Si-C Bond

The chemistry of silylene-transition-metal complexes LnM（=SiR2）SiR3 is one of the attractive synthetic targets in organometallic chemistry for such complexes are key intermediates in many transition metal-catalyzed systems.In the present work,the novel insertion reactions of an isocyanide into the Cp＊Mo（CO）2（=SiMe2）（SiMe3） Si-C bond were investigated extensively by using the DFT method.The effective core potentials（ECP） with a double-ζ valence basis set（LanL2DZ） were employed for Mo and Si and the standard 6-31G basis set for all other atoms.Polarization functions[22] were added for Si（ζd = 0.262）,C（ζd = 0.8） and N（ζd = 0.8）.The effect of solvent was evaluated with the standard PCM model.Our calculations show that the two-step channel is energetically favorable,and the solvation mode has minor influence on the relative energies.

Synthesis and Infrared Spectra Computation of Sterically Congested 2,2-Disubstituted Indane-1,3-dione Derivatives

Sterically congested 2,2-disubstituted indane-1,3-dione derivatives have been syn-thesized and characterized by 1H NMR,13C NMR,FT-IR and elemental analysis.The B3LYP/HF calculations for computation of IR spectra have been carried out for the title compounds at the 6-31G and 6-311＋＋G basis set levels.Predicted vibrational frequencies have been assigned and compared with the experimental FT-IR spectra and they are supported each other.

Solid-phase Synthesis of PNA Monomer by Ugi Four-component Condensation Reaction

Peptide nucleic acids (PNA) oligomers were synthesized in most cases by peptide synthesis from N-protected monomers. In this work a new method of obtaining PNA monomer by Ugi four-component condensation reaction was tested by solid-phase synthesis. The Fmoc protected PNA monomer was build up with thymin-1-yl acetic acid, 3-methylbutyl aldehyde, Fmoc protected aminoethyl isocyanide and Gly-Wang resin.

Luminescent Tetranuclear Copper(I) Phenylacetylide Complex with Cyclohexyl Isocyanide

Depolymerizing copper(I) phenylacetylide [Cu(C≡CPh)]n with cyclohexyl isocy- anide (CNCy) gave a tetranuclear copper(I) complex Cu4(CNCy)4(μ-η1-C≡CPh)2(μ3-η1,η1, η2-C≡ CPh)2. Crystal data: C30H32Cu2N2, Mr = 547.66, space group P1, a = 8.6448(1), b = 11.5772(2), c = 14.6666(4) ?, α = 88.387(2), β = 86.826(2), γ = 68.222(1)°, V = 1360.97(5) ?3, Z = 2, F(000) = 568, Dc = 1.336 g/cm3, μ = 1.582 mm-1, the final R = 0.0629 and wR = 0.1282 for 3257 observed reflections with I > 2σ(I). The phenylacetylide adopts μ-η1 and μ3-η1,η1,η2 bonding modes. The compound shows intense luminescence in the solid state.