Phenyl diazomethane

The thermal decomposition in acetonitrile is of intermediate order in phenyl-diazomethane between 1 and 2. Thus two reaction paths are operative, one uni-molecular leading to nitrogen and a carbene, and the other bimolecular, involving two molecules of phenyldiazomethane, viz. 

At high concentrations of the diazo compound the kinetics approach second order, and at low concentrations first order. At 85 °C, = 7.8x10 sec and 

The photolysis of phenyldiazomethane in the presence of olefins leads to the formation of cyclopropanes the addition is largely stereospecific. The reactivity of phenyl carbene has also been examined with respect to insertion reactions . The ESR spectrum of triplet phenylcarbene has been observed in the photolysis of phenyldiazomethane at 77 °K . 

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Ecample Suzuki et. al. used a reaction strategy to expand the Cgo molecule, buckminsterfullerene, by adding divalent carbon equivalents. Adding phenyl diazomethane to Cgo. (I)> followed by the loss of molecular nitrogen, results in a Cgi compound. 

Kitatani et al. found that tungsten(VI) chloride would catalyse the formation of a range of oxazoles from benzoyl(phenyl)diazomethane and nitriles (Scheme 17).<74TL1531, 77BCJ1647> The reaction with acetonitrile was studied with a range of other metal chlorides, but all proved less satisfactory than WCle. They attributed the catalytic nature of tungsten(Vl) chloride to both its Lewis acidity and the affinity of tungsten for carbenes. 

Durch Ringerweiterung von Fluoren mittels Phenyl-diazomethans und Schwefeldehydrierung in siedendem Dekalin stellten W. Treibs und M. Quarg (111) das 5-Phenyl-l,2-benzazulen [102] dar, das iiber das Trinitrobenzolat rein erhalten wurde. 

When phenyl-diazomethane was employed, the observed order of reactions was intermediate between first and second ). 

Photolysis of methyl-phenyl-diazomethane in cis-butene gives mainly styrene formed by hydride shift and the isomeric cycloaddition products 60—62 139) ... 

The photosensitized decomposition reduces the hydride shift, as may be expected for a triplet species. However, the stereochemical change in the cycloaddition is relatively small. Similieir results were obtained by Baer and Gutsche for the sensitized photolysis of o-n-butyl-phenyl-diazomethane 63... 

Figure 4.6 Chemical shifts for the bridgehead C atoms and the methylene H-atoms and coupling constants j(CH) for the methano bridge C atoms in H2 for isomers 113a and 113b. The corresponding C atoms resonate in the region between 130 and 150 ppm together with all other sp -carbons of the fullerene sphere. For the 1,6-addition adduct of with (p-methoxy-phenyl)diazomethane, the peak position of the bridgehead C atoms was found by HETCOR analysis to be 138.65 ppm [110. ...

By conventional procedures, 106 gm of benzaldehyde reacts in 600 ml of ether with 66 gm of anhydrous hydrazine to give benzalhydrazone which is directly oxidized in anhydrous ether with 300 gm of mercuric oxide to phenyl-diazomethane.) (See Volume I, Chapter 15, p. 398, for oxidation of hydrazones, p. 390 for an alternative preparation of phenyldiazomethane.)... 

Di azoethyl benzene of Methyl phenyl-di azomethane [called (a-Diazo-athyl)-benzol or Methyl-phenyl-diazomethan in Ger], CsH5.C(N2).CH.3 mw 132.16, N 21.20% ... 

The first catalytic asymmetric cyclopropanation using an ylide as catalyst was reported by Aggarwal et al. in 1997 [95, 96]. Phenyl diazomethane was added slowly to a mixture containing sulfide 12, an enone and Rh2(OAc)4 (1 mol%). A sulfur ylide was generated in situ from the sulfide and phenyl diazomethane in the presence of the transition-metal catalyst (see Scheme 10.20), as in the epoxidations discussed earlier (see Section 10.2.1.3). 

Only one example of an NHC-containing olefin metathesis catalyst containing a transition metal other than ruthenium has been reported in the literature. The NHC-osmium complexes 53a and 53b (Scheme 2) are synthesized from the dichloro(i]6-p-cymene)osmium dimer by addition of the NHC prepared in situ and abstraction of the chloride, followed by introduction of the ben-zylidene moiety with phenyl diazomethane. 

The complex RuC12L3 (L = PPh3) is sequentially treated with molar quantities of (2-isopropoxy phenyl)diazomethane and Pcy3 (cy = cyclohexyl). What is the reaction product, and what reaction may it catalyze ... 

Methoxy-phenyl)-diazomethan- -diethylester E14b, 1334 (aus Hydrazon)... 

However, totally different reaction products are formed when ortho-carborane cluster reacts with phenyl diazomethane in the presence of Pd(OAc>2 and without any other irradiation as shown in Scheme 5. 

With this restriction in mind, other solutions of the same central idea and without the participation of free radical species are conceivable. For instance. 1,4 elimination of acetic acid shown in route H would yield ketene V directly, a contention that finds support in the favorable 1,5 elimination portrayed in XII (see Scheme 54.5). Analogously, a benzylic carbene precursor would also be in a position to give an acetylene if route F of Scheme 54.3 is handled in such a way as to prevent charge development. In fact, carbene XIV that would result from the 1,1 elimination of acetic acid from I, has been shown to give aldehyde III when furyl-phenyl diazomethane (XV) (an efficient carbene generator) was used as precursor. ... 

A survey of C50 reactivity with the dipoles ethyl diazoacetate (10) and phenyl diazomethane (10) indicated that they add... 

Carpino found that diphenylthiirene oxide (36) reacted with phenyl diazomethane to afford a low yield of 3,4,5-triphenylpyrazole (37) presumably by cycloaddition/SO-extrusion (Scheme 13) <79JA390>. 

In a laser flash-photolysis study, 2-phenyladamantene was generated in benzene at room temperature from 3-noradamantyl(phenyl)diazomethane. This strained cycloalkene decays with second-order kinetics to give a dimer, and reacts much faster with O2 and Bu3SnH than with methanol, thus revealing a substantial radical character. Diphenyldiazomethanes possessing stable /er -butylaminoxyl and Ullman s nitronyl nitroxide radicals, e.g. (25), have been prepared by photolysis of the parent diazomethanes. Analysis of ESR fine structures showed that the carbene and radical centres couple ferromagnetically in these molecules, as expected. 

Cyano-substituted alkenes are converted in high yields to the corresponding gew-diarylcyclo-propanes when reacted with diaryldiazomethanes at or above room temperature. Most reactions have been carried out with tetracyanoethene which,essentially, gives the 3,3-diaryl-l, 1,2,2-tetra-cyanocyclopropanes in quantitative yields in a number of solvents. Acrylonitrile reacts in an analogous fashion. Thus, when a mixture of acrylonitrile and (4-benzyloxyphenyl)phenyl-diazomethane was refluxed in heptane (98 °C), a mixture of the E- and Z-isomers of 2-(4-benzyl-oxyphenyl)-2-phenylcyclopropanecarbonitrile (4a) was obtained in 86% yield. ° When (4-benzyloxy-3-methoxyphenyl)phenyldiazomethane was used, a mixture of the E and Z-isomers of 2-(4-benzyloxy-3-methoxyphenyl)-2-phenylcyclopropanecarbonitrile (4b) was obtained in 85 /o yield. ... 

The first example of a cyclopropanation reaction involving a transient phosphorus-substituted carbene was reported in 1967. The copper-catalyzed decomposition of (dimethoxyphos-phoryl)(phenyl)diazomethane in refluxing hept-l-ene gave l-dimethoxyphosphoryl-2-pentyl-l-phenylcyclopropane (1) in 73% yield. No information on the stereochemistry of the cyclopropane 1 was reported. 

Dimethoxyphosphoryl)(phenyl)diazomethane (1.356 g, 6 mmol), copper powder (60 mg, 0.94 mmol), and hept-l-ene (lOOmL, 0.710 mmol) were heated at reflux for 12 h. After filtration through Celite and evaporation of unreacted alkene, distillation of the residue afforded the title compound yield 1.29 g (73%) bp 108 C/0.04 Torr. 

The stereochemistry of the cyclopropanation reactions is difficult to predict. (Dimethoxy-phosphoryl)carbene reacts stereospecifically with ( )-l,2-diphenylethene to give 3-dimethoxy-phosphoryl-/ra .v-l,2-diphenylcyclopropane. In contrast, photolysis of (dimethoxyphosphor-yl)(phenyl)diazomethane in the presence of (Z)-but-2-ene gave a mixture of diastereomeric m-isomers, (la,2, 3 )-2 and (la,2a,3a)-2, along with the /ranj-isomer, (la,2ot,3/ )-2, in 15, 3 and 5% yield, respectively. Reaction with ( )-but-2-ene afforded only two of the possible cyclopropanes, namely (la,2, 3 )-2, and (Ia,2a,3/S)-2. ... 

A solution of (dimethoxyphosphoryl)(phenyl)diazomethane (11.3 g, 50 mmol) and buta-1,3-diene (50 mL) in EtjO (150 mL) was irradiated at — 30 °C over 10 h. After evaporation of the solvent and excess butadiene under vacuum, the residue was subjected twice to column chromatography on silica gel with EtOAc (2500 mL) and a mixture of EtOAc/MeOH (8 2, 500 mL) as eluants. c/s-l-Dimethoxyphosphoryl-1-phenyl-2-ethenylcyclopropane distilled at 127°C/0.04 Torr as an oil which then crystallized yield 3.20g (25%) mp 49 "C. tranj-l-Dimethoxyphosphoryl-l-phenyl-2-ethenylcyclopropanc yield 3.09 g (24%) bp 107 C/0.001 Torr. 

With cyclohexene, the yields of fused cyclopropanes depend dramatically on the method of generation of the carbene, and on the substituents of the diazo derivatives. For a comparison, (diethoxyphosphoryl)(phenyl)diazomethane reacted with cyclohexene to give the cyclopropane adduct 3c in 54% yield in the presence of copper powder, and in 22% yield under photolytic conditions. With (dimethoxyphosphoryl)(methyl)diazomethane, formation of the cyclopropane derivative was not observed. ... 

A careful study of the stereochemistry has been performed for the reaction of (di-ethoxyphosphoryl)(phenyl)diazomethane with cyclohexene, and shows that only the cxu-phos-phoryl isomer exo-3c was obtained. ... 

To a refluxing cyclohexane solution (200 mL) of copper powder (1 g, 15.7 mmol) was slowly added over 2 h a solution of (diethoxyphosphoryl)(phenyl)diazomethane (5.1 g, 20 mmol) in cyclohexene (200 mL). After 64 h under reflux, the reaction mixture was filtered and the residue washed with cyclohexene. The solvent was removed under vacuum, and the oily residue was subjected to column chromatography on silica gel with EtjO (2000 mL), and mixtures of EtjO/MeOH (2000 mL, 98 2 and 2000 mL, 96 4) to give the title compound as a solid yield 3.3 g (54%) mp 47-48 C. 

A solution of (dimethoxyphosphoryl)(phenyl)diazomethane (6.8 g, 30 mmol) in benzene (270 mL) was irradiated for 20 h (100 % evolution of Ns). The solvent was removed under vacuum and the viscous residue was treated with benzene (10 mL). After filtration, the precipitate was washed with benzene. Crystallization (EtOAc) afforded 3 as white crystals yield 1.9 g (27%) mp 244-246°C. The mother liquors were concentrated under vacuum and the residue was subjected to silica gel column chromatography (250 g). Successive elution with EtjO (3000 mL) (the column was cooled with water), EtOAc (1500 mL) and a mixture of EtOAc/MeOH (95 5, 1000 mL) gave 2 yield 1.5 g (18 %) mp 107 °C. Crystallization (EtjO/— 70 C) gave white crystals with the same mp. 

This reaction cannot be extended to all 1,4-disubstituted benzenes. For example, the photolysis of (dimethoxyphosphoryl)(phenyl)diazomethane in 1,4-dimethylbenzene yielded a complex mixture of products arising from radical intermediates. ... 

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