Presence Of Isocyanide Research Articles

Into the Blue: Ketene Multicomponent Reactions under Visible Light.

For the first time, a detailed study on the photophysical properties of variously substituted diazoketones and on their photoreactivity under blue LED irradiation was carried out. Despite very limited absorbance in the visible region, we have demonstrated that, independently from their structure, α-diazoketones all undergo a very efficient Wolff rearrangement. Contrarily to the same UV-mediated reaction, where photons can give rise to side processes, in this case, almost all absorbed photons are selective and effective, and the quantum yield is close to 100%. If the rearrangement is carried out in the presence of isocyanides and carboxylic acids/silanols, the photoreactivity is not affected, and the resulting ketenes can afford α-acyloxy- and α-silyloxyacrylamides through two distinct multicomponent reactions, performed both in batch and under continuous flow, with improved selectivity and broader scope. These photoinduced multicomponent reactions can be coupled with other visible-light-mediated transformations, thus increasing the diversity of the molecules obtainable by this approach.

Co-Catalyzed Synthesis of N-Sulfonylcarboxamides from Carboxylic Acids and Sulfonyl Azides.

A Co-catalyzed effective synthesis of N-sulfonylcarboxamides from the reaction of carboxylic acids and organic azides in the presence of isocyanide has been developed. The protocol has the advantages of short time, low temperature, and being oxidant-free, which provides a new and simple approach for the synthesis of N-sulfonylcarboxamides in good to excellent yields with a broad substrate scope.

A Visible‐Light‐Driven, Metal‐free Route to Aromatic Amides via Radical Arylation of Isonitriles

AbstractThe photochemical metal‐free carboamidation of aryl radicals has been exploited for the preparation of aromatic amides, including hetero‐ and polyaromatic derivatives, under visible light irradiation of arylazo sulfones in the presence of isocyanides in aqueous acetonitrile. The process was useful for the smooth preparation of the antidepressant moclobemide.magnified image

Alkyl Isocyanides Promoted Synthesis of Functionalized Azadienes from Dialkyl Acetylene Dicarboxylates and N-Hydroxysuccinimide

The reaction between N-Hydroxy succinimide with dialkyl acetylene dicarboxylates in the presence of isocyanides, leads to functionalized azadienes in good yields. The product were analized and the structures of reaction compounds were deduced from their IR, 1HNMR and 13CNMR spectra.

ChemInform Abstract: An Environmentally Benign Approach for the Synthesis of 3,4,5‐Trisubstituted 2‐Aminofurans under Solvent‐Free Conditions via Isocyanide‐Based Multicomponent Approach.

Abstract An efficient solvent-free procedure for the synthesis of 3,4,5-trisubstituted 2-aminofurans has been developed via a multicomponent strategy by the solid state condensation of finely grounded dibenzoylacetylene and aromatic aldehydes in the presence of isocyanides at room temperature. Clean reaction profile, easy work-up procedure, non-chromatographic purification technique, short reaction times, high yields, and solvent-free reaction conditions are the remarkable advantages of this procedure. Single crystal X-ray diffraction has been established for four structures.

An environmentally benign approach for the synthesis of 3,4,5-trisubstituted 2-aminofurans under solvent-free conditions via isocyanide-based multicomponent approach

An efficient solvent-free procedure for the synthesis of 3,4,5-trisubstituted 2-aminofurans has been developed via a multicomponent strategy by the solid state condensation of finely grounded dibenzoylacetylene and aromatic aldehydes in the presence of isocyanides at room temperature. Clean reaction profile, easy work-up procedure, non-chromatographic purification technique, short reaction times, high yields, and solvent-free reaction conditions are the remarkable advantages of this procedure. Single crystal X-ray diffraction has been established for four structures.

Synthesis of Cyano-pyrrolo[1,2-a][1,10]phenanthroline Derivatives Using a Multicomponent Condensation

1,10-Phenanthroline reacts with malonitrile and aldehydes in the presence of isocyanides as domino-Knoevenagel-nucleophilic cycloaddition for generation of a new class of 10-(aryl)-11-(alkyl- or arylamino-)pyrrolo[1,2-a][1,10]phenanthroline-9-carbonitrile compounds in excellent yield. All compounds are fully characterized with one structurally authenticated by a single X-ray diffraction study.

Synthesis of functionalized azadienes from aminobenzothiazole, acetylenic esters and isocyanides

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

Study of reaction between activated acetylenes and N,N′‐diethyl‐2‐thiobarbituric acid in the presence of isocyanides or triphenylphosphine

AbstractIn a series of separate experiments reaction between N,N′‐diethyl‐2‐thiobarbituric acid and acetylenic diesters in the presence of isocyanides or triphenylphosphine led to highly functionalized 4H‐pyrano[2,3‐d]thiopyrimidine or 1,4‐di‐ionic organophosphorus derivatives. The 1H NMR spectra of diethyl‐7‐(2,6‐dimethylphenylamino)‐4‐oxo‐2‐thio‐ 1,3‐diethyl‐4H‐pyrano[2,3‐d]pyrimidine‐5,6‐dicarboxylate showed dynamic NMR effect that was attributed to restricted rotation around the aryl‐nitrogen single bond. Activation free energy (ΔG≠) for this process is about 54.85 ± 2 kJ mol−1. Betaines as 1,4‐diionic organophosphorus compounds in this reaction are possessed of two vicinal stereogenic centers and exist in the solution as a mixture of two diastereoisomers. © 2010 Wiley Periodicals, Inc. Heteroatom Chem 21:228–235, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20601

Preparation and electrochemical reactions of nickel(II) complexes containing isocyanide and mono- or di-phosphines

Reactions of cis-NiCl 2(diphos) (diphos = PPh 2(CH 2) n PPh 2: n = 2 (dppe); n = 3 (dppp)) with isocyanide in the presence of NH 4PF 6 gave [NiCl(diphos)(XylNC) 2](PF 6) ( 1, 2) or [Ni(diphos)RNC) 3](PF 6) 2 ( 3, 4) (R = 2,6-Me 2C 6H 3 (Xyl), 2,4,6-Me 3C 6H 2 (Mes)). Similar reactions of NiCl 2(PPh 3) 2 with xylyl isocyanide gave [NiCl(PPh 3) 2(XylNC) 2](PF 6) 5 and [Ni(PPh 3) 2(XylNC) 3](PF 6) 2 6. The structures of these five-coordinated complexes were confirmed to be square-pyramidal by X-ray analyses: [NiCl(dppp)(XylNC) 2](PF 6) · CH 2Cl 2 2a, a = 13.345(2) Å, b = 10.984(2) Å, c = 33.082(4) Å, β = 97.13(1)°, V = 4812(3) Å 3, monoclinic, P2 1/ c, z = 4, R = 0.064; [Ni(dppe)(MesNC) 3](PF 6) 2 3b, a = 12.763(3) Å, b = 13.110(3) Å, c = 17.114(3) Å, β= 102.55(2)°, V= 2795(2) Å 3, monoclinic, P n , z = 2, R = 0.051; [NiCl(PPh 3) 2(XylNC) 2](PF 6) 5a, a = 13.768(5) Å, b = 17.23(1) Å, c = 11.063(6) Å, α = 98.86(4)°, β = 95.97(4)°, γ =75.48(3)°, V = 2504(2) Å 3, triclinic, Pl, z = 2, R = 0.063. The CV's of these complexes showed to be quasi-reversible with two-electron transfer. The potentials of complexes ( 1, 2, 5) shifted to more negative region than those of the corresponding 3, 4, and 6, respectively. There exists an equilibrium between 1 and 3 in the presence of isocyanide on the basis of the E 1/2 potentials, but no equilibrium between 2 and 4. Complex 5 was completely converted to 6 in the presence of xylyl isocyanide. These complexes were not influenced for excess diphosphine.

Zur Reaktion von Isocyaniden mit Nitriliminen[1]

AbstractOn the Reaction of Isocyanides with Nitrile IminesFour competing reactions have been found to occur when nitrile imines 2 are generated from 1 in the presence of isocyanides 3. The products obtained include i) 1,2,3‐triazolium salts 6, ii) 1,2,4‐triazolium salts 8, iii) dihydrotriazolyl‐substituted pyrazolamines 11, and iv) unstable 1,2‐diazetimine derivatives 12 which in turn give carbodiimides 13, nitriles 14, quinoxalinamines 15, and possibly 1,2,4‐triazoles 16 (after addition of 2). The proportions, in particular those of 6, 8, and 11, depend on the reaction conditions; thus, triethylamine used in excess can oppress the formation of 6 in favour of 8 and 11. ‐ The structure of 11 has been elucidated by means of X‐ray diffraction analyses of 11a and c.

Synthesis and structure of some palladium(I) cluster compounds containing isocyanide ligands

The reaction of [Pd 4(μ-CO) 4(μ-O 2CCH 3) 4] with C 8H 9NC has been shown to occur with substitution of CO by C 8H 9 NC to give [Pd 4(μ-CO) 2(μ-CNC 8H 9) 2(μ-O 2CCH 3) 4] ( 1 with two equivalents of isocyanide and [Pd 4(μ-CNC 8H 9) 4(μ-O 2CCH 3) 4] ( 2) with four equivalents of isocyanide. The structure of [Pd 4(μ-CNC 8H 9) 4(μ-O 2CCH 3) 4]· CH 2Cl 2 has been determined by single crystal X-ray diffractometry. The structure is based on a rectangular unit of palladium atoms with the two shorter edges, which have PdPd distances of 2.6572(5) and 2.6668(4) åA, bridged by isocyanide ligands, and the two longer edges, with PdPd distances of 2.8888(4) and 2.9369(4) åA, bridged by two acetate ligands. The bridging isocyanide groups are nearly linear, with CNC angles of between 161.2(4) and 169.3(5)°. This leads to relatively high values for the v(NC) stretching frequencies in the IR spectrum. Compound 1 has also been synthesised by carbon monoxide reduction of palladium(II) acetate in the presence of isocyanide.

Electrochemical Reactions of Dihalobis(isocyanide)nickel(II) at Platinum and Mercury Electrodes

Abstract Electrochemical reactions of divalent nickel complexes, NiX2(RNC)2 (1) (X = I, Br, Cl; R = 2,6-Me2C6H3 (Xyl), 4-Br-2,6-Me2C6H2, 2,4-t-Bu2-6-MeC6H2, 2,4,6-t-Bu3C6H2) were carried out at Hg and Pt electrodes. Cyclic voltammograms (CVs) of 1 at a Pt electrode showed a quasi-reversible redox wave at ca. −0.50 V, due to two-electron reduction [(1) (1)2−]. The reduction potential of the iodide (1a) or bromide (1f) complex (R = Xyl) shifted to the positive side by ca. 0.3 V in the presence of isocyanide, due to the electrochemical reaction of NiX2(RNC)3 (X = I, Br). The chloride complex (1e) showed a similar potential in the presence or absence of isocyanide; there exists no five-coordinated complex. The CV of 1a at a Hg electrode showed a redox wave at −0.74 V, due to the redox reaction of the unsaturated species, “[Ni(RNC)2HgI2]” (4) formed from the reaction of 1a with Hg, suggesting the CE mechanism. Compound 1a had a redox potential at −0.72 V in the presence of 2,6-xylyl isocyanide, being responsible for [Ni(RNC)4HgI2]2. The bromide complex showed a similar behavior, but the chloride complex underwent a very complicated reaction. The electrochemical mechanism of NiX2(RNC)2 with or without isocyanide is discussed.

Four- and Five-Coordinated Nickel(II) Isocyanide Complexes and Donor–Acceptor Complexes Containing Nickel and Mercury

Abstract Reaction of NiI2(RNC)2 (1) (a: R=2,6-Me2C6H3; b; 4-Br-2,6-Me2C6H2; c: 2,4-t-Bu2-6-MeC6H2: d: 2,4,6-t-Bu3C6H2 with RNC or PPh3 gave NiI2(RNC)3 (2) or NiI2(PPh3) (RNC)2 (3) (a: R=2,6-Me2C6H3; b: 2,6-Me2-4-BrC6H2). An X-ray analysis of (3a) showed that the complex has a trigonal bipyramidal structure; crystal data: Space group Pna21; a=21.577(2), b=9.440(1), c=17.075(1) Å, α=β=γ=90.0°, V=3477.7(6) Å3, R=0.0444. The bromide and chloride complexes, NiX2(2,6-Me2C6H3NC)2 (1e: X=Cl; 1f: X=Br) did not produce five-coordinated species. When complexes (1a, 1b, 1e, or 1f) were treated with Hg in the presence of isocyanide, the donor–acceptor complexes [Ni(RNC)4HgX2]2 (X=I, Br, or Cl) (4) were formed. An X-ray analysis of (4b) (R=4-Br-2,6-Me2C6H2) was undertaken; crystal data: Space group: Pl (triclinic); a=12.709(3), b=16.145(3), c=12.614(3) Å, α=96.11(2), β=107.67(2), γ=73.11(2)°, V=2359.5(10) Å3, R=0.0686. The complex is a donor-acceptor complex containing the Ni–Hg bond and has a dimeric structure bridged by two I atoms. The configuration around Ni is the trigonal bipyramid and around Hg, distorted tetrahedron.

Preparation and characterization of rhodium pentamethylcyclopentadienyl isocyanide complexes, (C5Me5)Rh(CNR)2 and [(C5Me5)Rh(CNR)]2 complexes

Several complexes of the type (C{sub 5}Me{sub 5})M(CNR)X{sub 2} have been prepared, where M = Rh and Ir, X = Cl, Br, and I and R = Me, t-Bu, neo-Pn, i-Pr, 2,6-xylyl, and CH{sub 2}-adamantyl. Two members of this series have been structurally characterized. The crystal structures of (C{sub 5}Me{sub 5})Rh(CrMe)Cl{sub 2} and (C{sub 5}Me{sub 5})Ir(Cn-2,6-xylyl)I{sub 2} are reported. Reduction of the dihalide derivatives in the presence of isocyanide provides a general route to the bis-substituted products (C{sub 5}Me{sub 5})Rh(CNR){sub 2} (R = Me, t-Bu, neo-Pn, i-Pr, 2,6-xylyl, CH{sub 2}-adamantyl). Reduction of the dihalide complexes in the absence of added isocyanide gives the dimers ((C{sub 5}Me{sub 5})Rh({mu}-CNR)){sub 2}, one of which has been characterized by x-ray crystallography (R = 2,6-xylyl). 25 refs., 3 figs., 6 tabs.

Covalent coupling of proteins to erythrocytes by isocyanide. A new, sensitive and mild technique for identification and estimation of antibodies by passive hemagglutination

A mild method for covalent coupling of protein-antigens to the surface of red blood cells (RBC) is described. The method is based on the formation of covalent bonds between aldehyde groups of oxidized RBC and amino or carboxyl groups of proteins in the presence of isocyanide. Very low concentrations of antibodies (8–30 ng/ml) could be detected in antisera with the specifically sensitized RBC as reagents in passive hemagglutination with no or very low non-specific agglutination.

ChemInform Abstract: SYNTHESIS OF AMIDES FROM CARBOXYLIC ACIDS AND AMINES IN THE PRESENCE OF ISOCYANIDES

Chemischer InformationsdienstVolume 10, Issue 2 Preparative Organic Chemistry ChemInform Abstract: SYNTHESIS OF AMIDES FROM CARBOXYLIC ACIDS AND AMINES IN THE PRESENCE OF ISOCYANIDES H. AIGNER, H. AIGNERSearch for more papers by this authorD. MARQUARDING, D. MARQUARDINGSearch for more papers by this author H. AIGNER, H. AIGNERSearch for more papers by this authorD. MARQUARDING, D. MARQUARDINGSearch for more papers by this author First published: January 9, 1979 https://doi.org/10.1002/chin.197902140AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume10, Issue2January 9, 1979 RelatedInformation