Reaction Of Phenyl Azide Research Articles

Direct Utilization of Calcium Carbide with Transition Metal‐Free Condition to Synthesize of 1‐Monosubstituted‐1,2,3‐triazoles from Azides

AbstractThe utilization of calcium carbide as an acetylide specie was an increasing concern in chemical society. Under transition metal‐ and base free conditions, calcium carbide was successfully proved as the acetylide resource to synthesize 1‐monosubstituted‐1,2,3‐triazoles from nucleophilic addition with azides. In this reaction, aryl azides achieved corresponding 1,2,3‐triazoles in good to excellent yields, and a gram‐scale reaction of phenyl azide with calcium carbide was conducted with an excellent yield. Alkyl azides could also participate in the reaction to prepare corresponding 1,2,3‐triazoles with moderate yield. Calcium acetylide hydroxide Ca(OH)C≡CH might be the critical intermediate. The process provided a green and sustainable prospect to utilize calcium carbide resource.

On the Synthesis of a T‐Shaped Imido Nickel Complex and Trigonal Amido Nickel Complexes

AbstractThe synthesis of a T‐shaped imido nickel complex is reported, obtained by the reaction of phenyl azide with the linear nickel(I) silylamide complex K{18‐crown‐6}[NiL2] (L=−N(Dipp)SiMe3; Dipp=2,6‐diisopropylphenyl). In addition, an unusual shift of a SiMe3 unit from an ancillary ligand to a putative [Ni=NPh] complex is observed. Examination of the resulting [Ni=NDipp] complex for its electronic properties leads to its description as a low‐spin nickel(III) imide and revealed only limited activity with respect to H‐atom abstraction from C−H bonds or nitrene. Attempts to obtain information about the general features of trigonal nickel(II) amide products, that would result from such a H‐atom abstraction reaction, via reaction of linear nickel(II) silylamide [NiL2] with alkali metal salts of primary amides revealed the reduction to the linear nickel(I) complex K{18‐crown‐6}[NiL2]. The same is observed for alkoxides, secondary amides or benzyl. Reaction of the organic salts with the anionic nickel(II) complex NBu4[NiBrL2] under salt elimination also give the linear nickel(I) complex. Partial formation of an otherwise stable T‐shaped nickel(II) can be observed only for the electron‐poor diphenyl amide. This implicates that reduction of the starting nickel(II) complexes by different organic alkali metal salts likely does not occur via a homolytic Ni−R bond cleavage but a direct SET process from the unligated substrate to the nickel(II) ion.

A molecular electron density theory study of the Grignard reagent‐mediated regioselective direct synthesis of 1,5‐disubstituted‐1,2,3‐triazoles

AbstractThe [3 + 2] cycloaddition (32CA) reaction of phenyl azide4with ethynylbenzene5in presence of ethyl magnesium bromide (EtMgBr) has been studied within the Molecular Electron Density Theory with the aim to rationalise the high‐yielding direct regioselective synthesis of 1,5‐disubstituted‐1,2,3‐triazoles. Topological analysis of the electron localisation function (ELF) of phenyl azide4indicates that it has azwitterionicstructure participating inzw‐type32CA reactions. Computed activation parameters along the two feasible reaction paths for this 32CA reaction makes the rationalisation of the experimental outcomes possible. Grignard reagent‐mediated processes have a polar character and complete regioselectivity, which is in line with the fast, clean, and high yielding reaction experimentally observed. The reaction follows aone‐stepmechanism involving a high asynchronous transition state structure. Topological analysis of the ELF and calculated quantum theory of atoms‐in‐molecule parameters indicate that formation of new C–N single bonds does not begin exactly at the corresponding transition state structure.

Synthesis of Complex Boron-Nitrogen Heterocycles Comprising Borylated Triazenes and Tetrazenes Under Mild Conditions.

The reactions of organic azides with diaryl(dihalo)diboranes(4) were explored, resulting in the observation of a number of surprising reactivity patterns. The reaction of phenyl azide with 1,2-diaryl-1,2-dihalodiboranes(4) resulted in the formation of five-membered rings comprising diboryl-triazenes with retention of the boron-boron bond, while the reaction of the peculiar 1,1-di(9-anthryl)-2,2-difluorodiborane(4) with phenyl azide yielded a six-membered ring bearing a diboryl-triazene, whereby the B-B bond was ruptured by the insertion of an arylnitrene-like reactive intermediate. Both types of heterocycles feature unprecedented connectivity patterns and are very rare examples of boryl triazenes beyond the more common 1,2,3-triazolatoboranes. They are also the product of a unique type of aryl migration from a boron center to the phenyl azide γ-nitrogen center. Lastly, the substitution of 1,2-diaryl-1,2-dihalodiboranes(4) with azide groups, using trimethylsilyl azide as the transfer reagent, yielded boryl-tetrazaboroles and diboryldiazadiboretidines (as side-products), invoking the intermediacy of the first N-boryl-substituted iminoboranes, which are BN isosteres of monoborylated alkynes. The synthetic results are complemented with mechanistic proposals derived from quantum-chemical calculations.

Influence of the Metal Orbital Occupancy and Principal Quantum Number on Organoazide (RN3) Conversion to Transition-Metal Imide Complexes

The reaction of phenyl azide with (PNP)Ni, where PNP = ( (t)Bu 2PCH 2SiMe 2) 2N (-), promptly evolves N 2 and forms a P=N bond in the product (PNP=NPh)Ni (I). A similar reaction with (PNP)FeCl proceeds to form a P=N bond but without N 2 evolution, to furnish (PNP=N-N=NPh)FeCl. An analogous reaction with (PNP)RuCl occurs with a more dramatic redox change at the metal (and N 2 evolution), to give the salt composed of (PNP)Ru(NPh) (+) and (PNP)RuCl 3 (-), together with equimolar (PNP)Ru(NPh). The contrast among these results is used to deduce what conditions favor N 2 loss and oxidative incorporation of the NPh fragment from PhN 3 into a metal complex.

Photoisomerizable Heterodienes Derived from a Phosphine Borane

Stable relations: Reaction of phenylazide with a phosphine borane derivative gives rise to an intramolecularly stabilized phosphazide 1 (R=iPr, R′=mesityl) that undergoes an unprecedented photoisomerization process associated with a change from an Nα→B to an Nβ→B interaction (see scheme). The generality and possible reversibility of such phenomena are demonstrated with the related phosphazine adduct 2.

N- and C-Attacks on aromatics of phenylnitrenium ion generated from N-phenylhydroxylamine in the presence of trifluoroacetic acid containing polyphosphoric acid or trifluoroacetic anhydride

A phenylnitrenium ion formed from N-phenylhydroxylamine in the presence of trifluoroacetic acid (TFA) containing polyphosphoric acid (PPA) interacts with the counterion −O2CCF3 and the unshared electron-pair of H2O, showing Hammett’s ρ values −5.2 and −4.0 for N- and C-attacks on aromatics PhX (X = H, Me, Et, Ph and Cl), respectively. The ratio N-/C-attack for this nitrenium ion is lower than for the nitrenium ion interacting with only the counterion; the latter nitrenium ion is generated by the use of trifluoroacetic anhydride (TFAA) instead of PPA or by reaction of phenyl azide with aromatics in TFA. The ratio for the former nitrenium ion is affected by the aromatic substituent X: X = Me > X = Et > X = Ph > X = H > X = OMe at 20 and 50 °C. The order for X = Cl is between those of X = H and X = Ph at 20 °C, but highest at 50 °C. The ratio is increased by higher reaction temperature and by decreased concentration of TFA. The results are demonstrated from the mechanistic viewpoint for the nitrenium ions.

Bildung von 1,2,4‐Trithiolanen in Dreikomponenten‐Gemischen aus Phenyl‐azid, aromatischen Thioketonen und 2,2,4,4‐Tetramethylcyclobutanthionen: Eine Schwefel‐Transfer‐Reaktion unter Bildung von ‘Thiocarbonylthiolaten’ ((Alkylidensulfonio)thiolaten) als reaktive Zwischenstufen

Formation of 1,2,4‐Trithiolanes in Three‐Component Reactions of Phenyl Azide, Aromatic Thiones, and 2,2,4,4‐Tetramethylcyclobutanethiones: A Sulfur‐Transfer Reaction to ‘Thiocarbonyl‐thiolates’ ((Alkylidenesulfonio)‐thiolates) as Reactive IntermediatesThe reaction of PhN3 and aromatic thioketones 18 (two‐component reaction) at 80° yields only the corresponding imines 22, S, and N2. Under similar conditions, in the presence of sterically crowded 2,2,4,4‐tetramethyl‐cyclobutanethiones 19 (three‐component reaction), 1,2,4‐trithiolanes of type 20 are formed in good yields in addition to imines 22 (Scheme 4). In case of 19a and 19c (X = CO, CS), the symmetrical trithiolanes 21a and 21b, respectively, are also isolated. With 4,4‐dimethyl‐2‐phenyl‐1,3‐thiazole‐5(4H)‐thione (24) instead of aromatic thioketone 18, imine 25, trithiolane 21a, and 1,4,2‐dithiazolidine 26 are formed (Scheme 5). A reaction mechanism for the formation of 1,2,4‐trithiolanes 20 and 21, including an S‐transfer to generate ‘thiocarbonyl‐thiolates’ 2b and/or 2c and 1,3‐dipolar cycloaddition with a thioketone, is proposed in Scheme 7.

Reactions of aryl azides with alkenes in the presence of aluminium trichloride. Formation of novel aziridines fused to seven- and eight-membered rings

Reactions of aryl azides (1) with cyclohexene gave 3-(arylamino)cyclohexenes (2) and trans-1-chloro-2-(arylamino)cyclohexanes (3), whereas that of (1) with cycloheptene or cis-cyclo-octene afforded novel aziridines, 8-aryl-8-azabicyclo[5.1.0]octanes(4), or 9-aryl-9- azabicyclo[6.1.0]nonanes (5), respectively. The reaction of phenyl azide (1a) with cis-4-methylpent-2-ene yielded 3-anilino-2-chloro-4-methylpentane (10), but that with the trans-alkene gave 4-anilino-2-methylpent-2-ene (7) and 3-anilino-4-methylpent-1-ene (8). The similar reaction of (1) with 3-trimethylsilylcyclohexene or 3-trimethylsilyl-cis-cyclo-octene produced only (2) or 3-(arylamino)-cis-cyclo-octenes (2′). The formation of the aziridines or the ring-opened products was explained by a mechanism via an aziridinium–AlCl3 complex formed from an azide–AlCl3 complex.

Reaction of phenyl azide with N,N-dimethyl-aminomethylenephenylphosphines

Phenyl azide reacts with N,N-dimethylamino-P-phenylmethylenephosphines with cleavage of the phosphoruscarbon double bond and formation of the dimer of diiminophosphorane and amidines.

Reaction of phenylnitrenium ion with sulphides. A novel synthetic method for aminophenyl sulphide derivatives

The reaction of phenyl azide with sulphides in the presence of both trifluoroacetic acid and trifluoromethanesulphonic acid to produce 2- and 4-aminophenyl sulphides (2) and (3) was investigated in order to obtain information on the following points: the kinetics of decomposition of phenyl azide, the effect of addition of benzene to reaction systems, the replacement of phenyl azide by 1-phenyl-2-methyl-4,6-diphenylpyridinium salt, and the steric and electronic effect of substituents in the sulphides. The products are formed through an azasulphonium ion by reaction of phenylnitrenium ion with sulphide, followed by rearrangement of the alkyl group in the azasulphonium ion. Sulphides with primary alkyl groups larger than propyl result in selective formation of ortho-products (2), the mechanism of which is discussed in detail.

ChemInform Abstract: Mechanistic Investigation of the Photoinitiated Autocatalytic Chain Decomposition (PACD) Reaction of Phenyl Azide and Derivatives.

AbstractThe quantum yields of the disappearance of (I) increase with enhancement of the azide concentration.

PHOSPHINIMINES DERIVED FROM PHOSPHOLE DIMERS BY THE STAUDINGER REACTION

Abstract The Staudinger reaction of phenyl azide with the phosphine groups of phosphole dimers gives bis(phenylimino) derivatives. Hydrolysis or methanolysis leads to diphosphine dioxides with retention of configuration at the bridging phosphorus and inversion at the 2-phospholene phosphorus. This reaction is useful in providing access to a new isomeric form of the phosphole oxide dimer framework. Amines catalyze the rearrangement at the 2-phospholene phosphorus to the isomeric form which is commonly produced on dimerization of phosphole oxides. Amides also catalyze the inversion at the 2-phospholene group in the Staudinger product. Both the original and the rearranged Staudinger product were found to be reduced with trichlorosilane to give the same diphosphine.

Mechanistic investigation of the photoinitiated autocatalytic chain decomposition (PACD) reaction of phenyl azide and derivatives

The quantum yields of the disappearance of (I) increase with enhancement of the azide concentration.

Inter- and intra-molecular aromatic N-substitution by arylnitrenium–aluminium chloride complexes generated from aryl azides in the presence of aluminium chloride

Reactions of phenyl azide with aromatic compounds (i.e. benzene, toluene, ethylbenzene, cumene, anisole, and bromobenzene) in the presence of AlCl3 gave diarylamines, whereas those of phenyl azides with an electron-donating group such as Me and OMe yield little of the corresponding diarylamines (tar formation takes place). The reaction of 4-nitrophenyl azide with benzene in the presence of AlCl3 gave 4-nitrophenyl(phenyl)amine and a C-substitution product, 2-amino-5-nitrobiphenyl. Decomposition of 2-azidophenyl(phenyl)methane and 2-azidobiphenyls in CH2Cl2 in the presence of AlCl3 underwent an N-cyclization to afford 9,10-dihydroacridine and carbazoles, respectively, in good yields. The kinetic data on the decomposition of aryl azides and a Hammett plot (with ρ–6.0) for the formation of diarylamines suggest that the products are formed by an aromatic N-substitution of arylnitrenium–AlCl3 complexes via azide–AlCl3 complexes. We further argue the character of arylnitrenium–AlCl3 complexes.

A novel ring-opening reaction of an aziridinium–AlCl3complex. Reaction of phenyl azide with alkenes in the presence of AlCl3

Reaction of phenyl azide with alkenes in the presence of AlCl3 gives an aziridinium–AlCl3 complex viaan azide–AlCl3 complex; this reaction is followed by ring-opening reactions of the aziridinium–AlCl3 complex to give N-allylanilines and/or N-phenyl-β-chloroamines after work-up with aqueous Na2CO3, but the reaction with cis-cyclo-octene yields a novel aziridine, 9-phenyl-9-azabicyclo[6.1.0]nonane after the work-up.

Addition of phenylnitrenium ion to olefins. Reactions of phenyl azide with some olefins in the presence of trifluoroacetic acid

Addition to cyclohexene, cis- or trans-4-methylpent-2-ene, or hex-1-ene of a singlet phenylnitrenium ion, generated from phenyl azide in the presence of trifluoroacetic acid, gave stereo- or regio- specifically N-phenyl-β-hydroxyamines (after work-up with aqueous Na2CO3)via aziridinium ions together with N-allyl- and 2- and/or 4-allylanilines. Use of methyl acrylate or methyl crotonate as an electron-deficient olefin led to the formation of N-phenylserine or N-phenylthreonine methyl ester (after work-up with aqueous Na2CO3), respectively. In the reaction with 1,1-disubstituted ethylene or styrene derivatives, N-substituted anilines were formed through an attack of either tertiary alkyl or benzylic cations on phenyl azide.

1,3-Dipolar Cycloaddition Reactions of 6-Methylenetricyclo[3.2.1.02,7]oct-3-en-8-one and Its Related Compounds

Abstract The cycloaddition reactions of 1,5-dimethyl-6-methylenetricyclo[3.2.1.02,7]oct-3-en-8-one (1a), its corresponding -8-endo-ol (1b), 1,5,8-trimethyltricyclo[3.2.1.02,7]oct-3-en-8-endo-ol (1c), and 5,8-dimethyl-9-methylenetricyclo[3.3.1.02,8]non-3-en-7-one (2) were investigated in order to study the origin of its stereoselectivity or site selectivity. The reaction of 2,4,6-trimethylbenzonitrile oxide (mesitonitrile oxide, MNO) with 1a, b occurs on the exo-mthylene group from the exo-side, but on the endocyclic double bond in the case of 1c. The compound 2 undergoes the addition of MNO on both the exocyclic and endocyclic double bonds to give a corresponding bis-adduct. On the other hand, the reaction of phenyl azide (PA) with 1a–c occurs on the endocyclic double bond from the endo-side to give a single adduct. The reaction of 6-exo-methoxy-1,5,6-trimethyltricyclo[3.2.1.02,7]oct-3-en-8-one with MNO or PA was also studied to prove the regioselectivity of the cycloadditions of constrained vinylcyclopropane moiety.

Pulsed-laser kinetic evidence for an oscillating reaction in the photoiniated autocatalytic chain decomposition (pacd) reaction of phenyl azide and of phenyl isocyanate

266 nm pulsed-laser excitation of 5.0 × 10 −1 M solutions of phenyl azide and of phenyl isocyanate affords a transient absorption which decays non-exponentially with at least six cycles of increasing/decreasing intensity, which are not sensitive to oxygen or argon gas, or monitoring wavelength. Oscillations occur on an ≈ 10 μs timescale, their number decreases With decreasing concentration, and are not observed for a 1.0 × 10 −2 M phenyl azide solution containing 0.8 × 10 −2 M tetracyano-ethylene. At 5.0 × 10 −4 M phenyl azide a single exponential decay is also observed. The oscillatory intensity is thought due to the reaction of phenylnitrene with phenyl azide and with phenyl isocyanate.

Reactions of olefin complexes with nitrene precursors. Synthesis of triazoline and aziridine complexes of palladium(II); crystal and molecular structure of trans-dichlorobis(11-phenyl-9,10,11-triazabicyclo-[6.3.0]undec-9-ene-N9)palladium–chloroform(1/2)

By reaction at 70 °C of phenyl azide with a suspension of PdCl2 and cis-cyclo-octene, the complex [PdCl2{[graphic omitted]H2}2]·2CHCl3 has been isolated, and its crystal and molecular structure determined. This compound crystallizes in triclinic space group P with a= 9.258(2), b= 10.702(3), c= 11.156(2)A, α= 113.94(3), β= 99.60(2), γ= 104.87(3)°, and Z= 1. The metal lies on a symmetry centre and the complex configuration is trans planar. The chloroform molecules are hydrogen bonded to the co-ordinated chloride ions. The reaction of phenyl azide with cis-cyclo-octene at 70 °C in the absence of PdCl2 leads to the corresponding anil, N-cyclo-octylideneaniline, PhN[graphic omitted]H2. Preformed [{PdCl2(cis-C8H14)}2] reacts with phenyl azide in cyclo-octene at 70 °C to give [PdCl2{[graphic omitted]H2}2]. By comparison, [{PdCl2[PhN[graphic omitted]H2]}2] has been synthesized from the reaction of [PdCl2(PhCN)2] with N-cyclo-octylideneaniline.