Butyl Isocyanide Research Articles

Metal Catalyst-Free One-pot Synthesis of Carboxamide Derivatives via Ugi-4CC Reaction and Its Anti-tubercular Study

Background: A new series of ten composites with sulphur based carboxylic acid and benzylamine were synthesized by Ugi 4-components reaction (Ugi-4CR) and screened for antituberculosis activity against the Mycobacterium tuberculosis H37Rv strain. Objective: Target compounds were isolated, purified, identified, and characterized by MS, FT-IR, 1HNMR, APT, and 13C-NMR then the antituberculosis activity was examined by Microplate Alamar Blue Assay (MABA) method. Methods: This study was based on the articulation of carboxamide linkage bearing S-linkage in the core unit by reacting four different units, i.e., 2-(pyrimidin-2-ylthio)acetic acid, aromatic aldehyde, benzylamine and tertiary butyl isocyanide at RT in an atom economy route of synthesis. The desired product (5a- 5j) was synthesized via one-pot and Metal-free conditions. Results: Compounds (5a-5j) synthesized in good yields and compared to MIC values of Isoniazid 0.05 (μg/mL), Rifampicin 0.1 (μm/mL), and Ethambutol 1.56 (μg/mL) as a positive control. Conclusion: Synthesized compounds give excellent yield. Among the ten derivatives, compound 5f has comparable antituberculosis activity.

Groebke–Blackburn–Bienaymé multicomponent reaction coupled with unconventional Pictet–Spengler cyclization for the synthesis of imidazo[4,5‐b]pyridine fused polycyclic heterocycles

AbstractA diverse library of fused tetracyclic and pentacyclic imidazo[4,5‐b]pyridine scaffolds was synthesized using an unconventional strategy, involving Groebke–Blackburn–Bienaymé (GBB) multicomponent reaction coupled with Pictet–Spengler (PS) cyclization. The reaction strategy involves the use of 2‐aminoazine, aldehyde, and 1,1,3,3‐tetramethyl butyl isocyanide in the GBB reaction followed by the dealkylation to generate a free amine, which on PS cyclization with another aldehyde generated a fused polycyclic heterocycle. A small set of 15 diverse polycyclic heterocycles were synthesized and their structures were confirmed by 1H NMR, 13C NMR, and mass spectrometric analyses. In addition, a single‐crystal X‐ray diffraction of one of the library members established the three‐dimensional structure of the polycyclic skeleton.

Catalytic pyrolysis of polyethylene waste with Fuller’s earth clay and metal oxides under mild conditions

Numerous studies have been conducted to investigate the suitable processing of polyethylene into fuel using various clay catalysts but they were found to be less active and their yield was also lower than other catalysts such as Y zeolite. Furthermore, the heavier liquid products were obtained by utilizing clay catalysts. Keeping this point in view, the current investigation aimed to examine the aspects of catalytic degradation of polymer utilizing fuller's earth clay as the catalyst and various metal oxides as an additive. A series of experiments were carried out using three different catalysts. The plastic used was high-density polyethylene (HDPE) waste, whereas blended mixtures of (ZnO + Clay), (Fe(III)Oxide + Clay), and (Ni Oxide + Clay) were used as a catalyst. The plastic (HDPE) catalytically cracked under controlled conditions of 300 °C and 22 psi and in half-hour reaction time via cylindrical reactor (1 ft length, 0.5 ft diameter with a lid. The gaseous mixture produced during the catalytic degradation of the polymer was then analyzed in a gas chromatograph-mass spectrometer. The proportion of products i.e., propene, butyl isocyanide, and 1-pentene produced using clay and Fe (III) Oxide was higher compared to the other two catalysts. The concentration wt% of propene, butyl isocyanide, and i-pentene in the case of Fe (III)Oxide + Clay catalyst were 55.10 wt%, 30.10 wt%, and 15.30 wt% as compared to ZnO + Clay catalyst and Ni Oxide + Clay catalyst which contain amounts lower than Fe(III)Oxide + Clay catalyst. This was primarily due to milder acidity and high active sites of the Clay + Fe (III) Oxide catalyst. Furthermore, the experimental setup developed in this work appeared to be feasible to produce low molecular weight hydrocarbons.

Reaction Between 7-Hydroxy Coumarin, Alkyl Isocyanides and Dialkyl Acetylenedicarboxylate: Synthesis of 4H-Chromenes and 1-Azabuta-1,3-dienes

The reactive intermediate generated by the addition of tert-butyl and 1,1,3,3-tetramethyl butyl isocyanide to dialkyl acetylenedicarboxylate was trapped by 7-hydroxycoumarin to produce highly functionalized 4H-chromenes in fairly good yields. When the reaction is performed with cyclohexyl isocyanide, 1-azabuta-1,3-dienes were obtained.

Formation of Germa-ketenimine on the Ge(100) Surface by Adsorption of tert-Butyl Isocyanide.

Reactions of the (100) surfaces of Ge and Si with organic molecules have been generally understood within the concept of "dimers" formed by the 2 × 1 surface reconstruction. In this work, the adsorption of tert-butyl isocyanide on the Ge(100)-2 × 1 surface at large exposures is investigated under ultrahigh vacuum conditions. A combination of infrared spectroscopy, X-ray photoelectron spectroscopy, and temperature-programmed desorption experiments along with dispersion-corrected density functional theory calculations is used to determine the surface products. Upon adsorption of a dense monolayer of tert-butyl isocyanide, a product whose structure resembles a germa-ketenimine (N=C=Ge) with σ donation toward and π back-donation from the Ge(100) surface appears. Formation of this structure involves divalent-type surface Ge atoms that arise from cleavage of the Ge(100)-2 × 1 surface dimers. Our results reveal an unprecedented class of reactions of organic molecules at the Ge(100) surface.

Formation of a Diaminoalkyne Derivative by Dialumane-mediated Homocoupling of t-Butyl Isocyanide

Treatment of a stable dialumane derivative with an excess of t-butyl isocyanide resulted in the homocoupling of the isocyanide to form a diaminoalkyne skeleton. A one-to-one insertion product of th...

ChemInform Abstract: Divergent Synthesis of 6H‐Isoindolo[2,1‐a]indol‐6‐ones and Indenoindolones: An Investigation of Pd‐Catalyzed Isocyanide Insertion.

AbstractPd‐catalyzed reaction of 2‐(o‐bromophenyl)‐indoles with isocyanides affords isoindoloindolones [cf.

Palladium-Catalyzed Synthesis of Biaryl Ketones via tert-Butyl Isocyanide Insertion

A simple and efficient palladium-catalyzed carbonylative Suzuki coupling via <i>tert</i>-butyl isocyanide insertion has been developed, which demonstrates the utility of isocyanides in intermolecular C–C bond construction. This methodology provides a novel pathway for the synthesis of diaryl ketones in moderate to good yields. The approach is tolerant to a wide range of substrates and applicable to library synthesis. A possible reaction mechanism was proposed based on the experimental results.

Reaction oftert-Butyl Isocyanide with Alkyl Propiolates in the Presence of α-Chloroketones

tert-Butyl isocyanide reacts with α-chloroketones in the presence of alkyl propiolates in one pot to afford functionalized γ-iminolactones as sole product in good yields.

Increased dipeptoid diversity resulting from post-condensational manipulation of the Ugi reaction products

5,6-Dihydropyrazolo[1,5- a ]pyrazines prepared via the Ugi reaction involving pyrazole-3-carboxylic convertible tert -butyl isocyanide and subsequent microwave-promoted cyclization, were found to be prone to opening with primary and secondary amines, thereby providing a facile, three-step access to a greater diversity of Ugi-type dipeptoids, some of which cannot be accessed via the Ugi reaction itself.

ChemInform Abstract: The Millimeter-Wave Rotational Spectrum of Tertiary Butyl Isocyanide.

The millimeter-wave rotational spectrum of tertiary butyl isocyanide, (CH3)3CNC, was measured in the ground state and in the first excited state of the doubly degenerate CNC bending mode vβ. Accurate spectroscopic constants for both states have been determined from frequency measurements spanning the range 146–333 GHz. The results are compared with those for tertiary butyl cyanide, for which improved ground state sextic distortion constants are reported. The experimental quartic centrifugal distortion constants and the Coriolis coupling constant ξβ are well reproduced by a rudimentary force field calculation. Coriolis coupling constants for bending modes of linear segments attached to symmetric top C3v molecules based on a tetrahedrally substituted carbon atom are compared and factors responsible for changes in their values are identified and discussed.

Straight-chain alkyl isocyanides open the distal histidine gate in crystal structures of myoglobin .

Crystal structures of methyl, ethyl, propyl, and butyl isocyanide bound to sperm whale myoglobin (Mb) reveal two major conformations. In the in conformer, His(E7) is in a "closed" position, forcing the ligand alkyl chain to point inward. In the out conformer, His(E7) is in an "open" position, allowing the ligand side chain to point outward. A progressive increase in the population of the out conformer is observed with increasing ligand length in P2(1) crystals of native Mb at pH 7.0. This switch from in to out with increasing ligand size also occurs in solution as measured by the decrease in the relative intensity of the low-frequency ( approximately 2075 cm(-1)) versus high-frequency ( approximately 2125 cm(-1)) isocyano bands. In contrast, all four isocyanides in P6 crystals of wild-type recombinant Mb occupy the in conformation. However, mutating either His64 to Ala, creating a "hole" to solvent, or Phe46 to Val, freeing rotation of His64, causes bound butyl isocyanide to point completely outward in P6 crystals. Thus, the unfavorable hindrance caused with crowding a large alkyl side chain into the distal pocket appears to be roughly equal to that for pushing open the His(E7) gate and is easily affected by crystal packing. This structural conclusion supports the "side path" kinetic mechanism for O(2) release, in which the dissociated ligand first moves toward the protein interior and then encounters steric resistance, which is roughly equal to that for escaping to solvent through the His(E7) channel.

Diaquatetrakis(tert-butyl isocyanide)cobalt(II) bis(perchlorate): an example of cobalt(II) coordinated by only four alkyl isocyanide ligands

The title compound, [Co(C5H9N)4(H2O)2](ClO4)2, crystallizes in the monoclinic space group C2/m. The cation has space-group-imposed 2/m symmetry, while the perchlorate ion is disordered about a mirror plane. The two slightly non-equivalent Co-C bonds [1.900 (3) and 1.911 (3) A] form a rectangular plane, with a C-Co-C bond angle of 86.83 (11) degrees, and the linear O-Co-O C2 axis is perpendicular to this plane. The C[triple-bond]N bond lengths are 1.141 (4) A and the Co-C[triple-bond]N and C[triple-bond]N-C angles average 175.5 (4) degrees. The perchlorate counter-ions are hydrogen bonded to the water molecules. The title compound is the first example of four alkyl isocyanide ligands coordinating Co(II) upon initial reaction of Co(ClO4)(2).6H2O/EtOH with alkyl isocyanide. In all other known examples, five alkyl isocyanide molecules are coordinated, as in [(RNC)5Co-Co(CNR)5](ClO4)4 (R = Me, Et, CHMe2, CH2Ph, C4H9-n or C6H11) or [Co(CNC8H17-t)5](ClO4)2. This complex, therefore, is unique and somewhat unexpected.

Reactivity of cyclopalladated compounds derived from biphenyl-2-ylamine towards carbon monoxide, tbutyl isocyanide and alkynes

The reactivity of the dimeric cyclopalladated compounds derived from biphenyl-2-ylamine (μ-X) 2[κ 2- N2 ′, C1 -1-Pd-2-{(2′-NH 2C 6H 4)C 6H 4}] 2 [X = OAc ( 1), X = Cl ( 2)] towards unsaturated organic molecules is reported. Compound 1 reacted with carbon monoxide and t butyl isocyanide producing phenanthridin-6(5 H)-one and N- tert-butylphenanthridin-6-amine in 63% and 88% yield, respectively. Compound 2 reacted separately with diphenylacetylene and 3-hexyne, affording the mononuclear organopalladium compounds [κ 2- N2 ″, C1 -η 2- C2 , C3 - 1-Pd{(R–C C–R) 2-2′-(2″-NH 2C 6H 4)C 6H 4}Cl] [R = Ph ( 5), R = Et ( 6)] in 50–60% yield, which derived from the insertion of two alkyne molecules into the C–Pd σ bonds of 2. The crystal structure of compounds 5 and 6 has been determined. Compound 5 crystallized in the monoclinic space group P2 1/ n with a = 13.3290(10) Å, b = 10.6610(10) Å and c = 22.3930(10) Å and β = 100.2690(10)°. Compound 6 crystallized in the triclinic space group P 1 ¯ with a = 7.271(7) Å, b = 10.038(3) Å and c = 16.012(5) Å, and α = 106.79(3)°, β = 96.25(4)° and γ = 99.62(4)°. The crystal structures of 5 and 6 have short intermolecular Pd–Cl⋯H–N–Pd non-conventional hydrogen bonds, which associated the molecules in chains in the first case and in dimers in the second.

Die Synthese von cis‐ und trans‐[Fe(CN)2(CNtBu)4] in einer Eintopfreaktion aus Fe2(CO)9 und tert. Butylisocyanid

AbstractSynthesis of cis‐ and trans‐[Fe(CN)2(CNtBu)4] in a One‐Pot Procedure from Fe2(CO)9 and tert. ButylisocyanideThe reaction of Fe2(CO)9 with tert. butyl isocyanide in the presence of 10 bar of carbon monoxide leads to the formation of the mononuclear trigonal bipyramidal compound [Fe(CO)3(CNtBu)2] with two axially coordinated isocyanide ligands. If the same reaction is carried out without additional carbon monoxide being present in the solution, a 1:1 mixture of the isomeric octahedral complexes cis‐ and trans‐[Fe(CN)2(CNtBu)4] is produced via a complex redox reaction involving the reductive cleavage of isocyanide ligands. The molecular structures of the product compounds is going to be discusssed. The crystal structures of cis‐ and trans‐[Fe(CN)2(CNtBu)4] are mainly determined by the ability of the cyano ligands to act as hydrogen bond acceptor sites.

Regioselective Reactions of N1‐Alkyl‐N2‐(4‐nitrophenyl)ethanediamide and Acetylenic Esters in the Presence of tert‐Butyl Isocyanide.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Regioselective reactions of N1-alkyl- N2-(4-nitrophenyl)ethanediamide and acetylenic esters in the presence of tert-butyl isocyanide

The regioselective reactions of N 1 -alkyl- N 2 -(4-nitrophenyl)ethanediamide with dialkyl acetylenedicarboxylates in the presence of tert -butyl isocyanide lead to dialkyl 2-{[2-(alkylamino)-2-oxoacetyl]-4-nitroanilino}-3-[( tert -butylimino)methylene]succinates in good yields.

A Simple Approach to the Synthesis of Dialkyl 5‐tert‐Butylamino‐[2,2′]bifuranyl‐3,4‐dicarboxylates.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Characterization of the High-Spin Heme x in the Cytochrome b6f Complex of Oxygenic Photosynthesis

X-ray structures at 3.0-3.1 A resolution of the cytochrome b(6) f complex from the cyanobacterium Mastigocladus laminosus [Kurisu, G., Zhang, H., Smith, J. L., and Cramer, W. A. (2003) Science 302, 1009-1014] and the green alga Chlamydomonas reinhardtii [Stroebel, D., Choquet, Y., Popot, J.-L., and Picot, D. (2003) Nature 426, 413-418] showed the presence of a unique heme, hemex, that is covalently linked by a single thioether bond to a Cys residue (Cys35) on the electrochemically negative (n) side of the cytochrome b(6) polypeptide. Heme x faces the intermonomer quinone exchange cavity. The only axial ligand associated with this heme is a H(2)O or OH(-) that is H-bonded to the propionate of the stromal side heme b(n), showing that it is pentacoordinate. The spectral properties of this heme were hardly defined at the time of the structure determination. The pyridine hemochromagen redox difference spectrum for heme x covalently bound to the cytochrome b polypeptide isolated from SDS-PAGE displays a low-amplitude broad spectrum with a peak at 553 nm, similar to that of other hemes with a single thioether linkage. The binding of CO and a hydrophobic cyanide analogue, butyl isocyanide, to dithionite-reduced b(6) f complex perturbs and significantly shifts the redox difference visible spectrum. Together with EPR spectra displaying g values of the oxidized complex of 6.7 and 7.4, heme x is defined as a ferric high-spin heme in a rhombic environment. In addition to a possible function in photosystem I-linked cyclic electron transport, the five-coordinate state implies that there is at least one more function of heme x that is related to axial binding of a physiological ligand.

A simple approach to the synthesis of dialkyl 5- tert-butylamino-[2,2′]bifuranyl-3,4-dicarboxylates

Reaction of tert-butyl isocyanide with electron-deficient acetylenic esters in the presence of N 1-[( Z)-1-benzoyl-3-oxo-3-phenyl-1-propenyl]-2-(2-furyl)-2-oxoacetamide leads to dialkyl 5- tert-butylamino-[2,2′]bifuranyl-3,4-dicarboxylates in moderate yields.