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.

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.

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.

Acetonitrile(CH_3CN)and methyl isocyanide(CH_3NC) adsorption on Pt(111)surface:a DFT study

The adsorption of CH3CN and CH3NC on the Pt（lll） surface at the 1/4 monolayer （ML） coverage has been car-ried out at the level of density functional theory for understanding hydrogenation processes of nitriles. The most favored ad-sorption structure for CH3 CN is the C--N bond almost parallel to the surface with the C-N bond interaction with adjacent surface Pt atoms. For CH3NC, the most stable configuration is the CH3 NC locates at the face center cubic （fcc） site with the C-atom bonded to three Pt atoms. In addition, the HCN and HNC adsorption has been computed, and the adsorption pattern is nearly similar to the CH3CN and CH3NC, respectively. The adsorbed molecules rehybridize on the surface, be-coming non-linear with a bent C-C-N or C-N-C angle. Furthermore, the binding mechanism of these molecules on the Pt（111） surface is also analyzed.

Oxidative cyclization of allyl compounds and isocyanide: A facile entry to polysubstituted 2-cyanopyrroles

A facile Tf OH-catalyzed oxidative cyclization of allyl compounds and isocyanide has been developed with the assistance of DDQ, where isocyanide is used as the crucial "N" and "CN" sources. Highly functionalized 2-cyanopyrroles are constructed efficiently through a new formal [3 + 2] mode, demonstrating diverse reactivity and synthetic utility in organic chemistry. 2-Cyanopyrrole is converted into a nucleobase analogue of Remdesivir and 5H-pyrrolo[2,1-a]isoindole through a three-step or a two-step sequence, respectively. This protocol features broad substrate scope, operational simplicity and good functional group tolerance.

Isocyanide-Based One-Pot Cascade Synthesis of 3-Acyl Isoindolinones

A series of 3-acyl-substituted isoindolinone derivatives were synthesized in a one-pot manner via the reaction of o-bromobenzaldehydes,isocyanides,and carboxylic acids in the presence of palladium catalyst and base. The reaction employing easily available starting materials features simple operation and high efficiency. The mechanistic study showed that the reaction might undergo 1) Pd-catalyzed [3+2] cyclization of o-bromobenzaldehyde with isocyanide and the re-insertion of another molecule of isocyanide,2) addition of carboxylic acid to in situ formed ketenimine followed by a rearrangement relay to give 3,3-diacyl-substituted isoindolinone derivative. Further transformations of the obtained products through decarbonylation could also be realized.

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 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.

1-Methylimidazole-catalyzed reaction between tosylmethyl isocyanide and dialkyl acetylenedicarboxylates:An efficient synthesis of functionalized pyrroles

An efficient 1-methylimidazole-catalyzed synthesis of dialkyl 2-[（4-methylphenyl）sulfonyl]-1H-pyrrole-3,4-dicarboxylates is described.The reactive 1：1 zwitterionic intermediate formed by the addition of 1-methylimidazole to dialkyl acetylenedicarboxylates is trapped by tosylmethyl isocyanide（TOSMIC） to afford the title compounds in excellent 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.

The First-principles Study on the Rectification of Molecular Junctions Based on the Alkyl-chain-modified[2,5?]Bipyrimidinyl(biphenyl isocyanide)gold(Ⅰ)

Using density functional theory(DFT)combined with nonequilibrium Green?s function investigates the electron-transport properties of several molecular junctions based on the[2,5?]bipyrimidinyl(biphenyl isocyanide)gold(Ⅰ)molecule(BPM-Au(Ⅰ)CN-BP),which is modified by one to three alkyl groups forming BPM-Au(Ⅰ)CN-BP(CH2)n.The asymmetric current-voltage characteristics have been obtained for the molecular junctions.Rectifying performance of Au/S-BPM-Au(I)CN-BP-S/Au molecular junction can be regulated by introducing alkyl chain.The M1 molecular junction exhibits the best rectifying effect.Its maximum rectifying ratio is 2109,which is about 150 times more than that of the molecular junction based on the original M.Moreover,all the systems modified by alkyl group have obvious negative differential resistance behavior(NDR).The current-voltage(Ⅰ-Ⅴ)curves of all the systems in this work are illustrated by transmission spectra.

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.

Aggregation-induced phosphorescence and mechanochromic luminescence of a tetraphenylethene-based gold(Ⅰ) isocyanide complex

In this study,a new twisting gold（Ⅰ） isocyanide complex based on tetraphenylethene（TPE）,TPE-NC-Au.was designed and synthesized.It exhibits aggregation induced phosphorescence（AIP） characteristics,owing to the incorporation of Au moiety and conformation rigidification in the aggregated states.Moreover,the emission color of the crystalline solid of TPE-NC-Au changes from blue（454 nm） to green（500 nm） in response to mechanical grinding,due to the combined effects of conformation planarization,enhanced π…π stacking,as well as the emergence of aurophilic interactions in the ground amorphous state.Notably,the emission color can be restored upon solvent fuming,associating with the reconstruction of crystalline lattices.The AIP and switchable mechanochromism of TPE-NC-Au make it suitable for potential applications in bioimaging,sensing,and optoelectronic devices.

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.

Facile Mechanochemical Preparation of Polyamide-derivatives via Solid-state Benzoxazine-isocyanide Chemistry

With the exploration of novel sustainable protocol for functional polyamides'(PAs)construction as the starting point,herein,the small molecular model compound(M 1-ssBIC)was prepared firstly by manual grinding of monofunctional benzoxazine(1a)and isocyanide(1 b)via solid-state benzoxazine-isocyanide chemistry(ssBIC)to evaluate the feasibility of ssBIC.Linear PAs(P1-series polymers)were subsequently synthesized from biunctional benzoxazine(2a)and isocyanide(2b),and the influence of the loading of catalyst(octylphosphonic acid)(OPA)on the polymerization was investigated.Afterwards,two kinds of cross-linked PAs were successfully constructed via ssBIC by using trifunctional benzoxazine(3a)and cross-linked polybenzoxazine(4a)as reaction substrates,respectively,thus verifying the adaptability of ssBIC.Structural characterization indicates that amide,phenolic hydroxyl and tertiary amine substructures,with metal-complexing capability,have been successfully integrated into the obtained PAs.A type of representative PA/silver composite(P3-AgNPs)was prepared subsequently via in situ reduction treatment,and its application as recyclable reduction catalyst for organic pollutant p-nitrophenol(4-NP)was preliminarily investigated here to provide the example for possible downstream application of ssBIC.We think that this current work could provide a new pathway for the construction of functional PAs through facile and sustainable ssBIC protocol.

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.

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.

Investigation of the Adsorption and Self Assembly of Isocyanide Derivatives on Au（111） Surface

The adsorption and self-assembly of isocyanide derivatives on Au（111） surface were investigated by density functional theory （DFF） and molecular dynamics simulation. The calculation for phenyl isocyanide by DFT was based on cluster and slab models. The self-assembled monolayers of 2-isocyanoazulene and 1,3-diethoxycarbony 1- 2-isocyanoazulene on Au（111） were simulated using Au-C force field parameters developed by us. It was found that the top site was the most preferred position, and the isocyanoazulene and its derivatives could form the ordered face to edge self-assembled monolayer on gold surface indeed, and the molecules stood on the gold surface vertically.