Diphenyl- -nitril

Hydroxy-2-athyI-3,3-diphenyl- -nitril 115 3-Hydroxy-3-aryl- -nitril 604 3-Hydroxy-2-benzyl- -nitril 206... 

The 1,2,4-diazaarsoles are colorless oils or crystals. The unsubstituted compound is deprotonated by butyllithium and subsequently alkylated or acylated at N-1 <86TL2957>. The 1-acyl derivatives (9) (R = Me, Ph) readily undergo a regiospecific cycloaddition of nitrones, nitrile oxides and diazoacetic esters (Scheme 1). The cycloaddition of diphenyl nitrile imine is more general in respect to the 1-substituent (R = H, Me, Ph, COMe). The cycloreversion of the adduct (10) at higher temperatures provides an in situ access to the 1,3-diphenyl diazaarsole (11) which immediately enters another cycloaddition (Scheme 2) <86TL2957>. 

Cycloaddition of diphenyl nitrile ylide (68 Ar = Ph, and the phosphaalkene, R = Ph) <88TL785>, or of (68 Ar = C6H4NO2-4), and phosphaalkynes, R = Bu, CMe2Et, 1-adamantyl, yields 1-unsub-stituted 1,3-azaphospholes (69). The cycloaddition of the phosphaalkynes is regiospecific however, the constitution of (69) could not be determined with certainty (Equation (9)) <90CRV191>. 

Nitrile imines react with isothiocyanates in a similar manner. For example, diphenyl nitrile imine 119, generated in the thermolysis of 2,5-diphenyltetrazole, reacts with isothiocyanates to give a mixture of 3,5-diphenyl-2-phenylimino-2,3-dihydro-l,3,4-thiadiazole 120 and 1,3,4-triphenyl-l,2,4-triazole -5-thione 121, indicating that the reaction proceeds across both the C=S and the C=N bonds of the isothiocyanate group... 

When diphenyl nitrile imine 123 is formed by dehydrochlorination of the hydrazidoyl chloride 122, phenylcarbonyl- and imidoyl isothyocyanates add exclusively across their C=S bonds to give the cycloadducts 124. 

In the first synthesis of T, the diphenyl ether was formed from -methoxyphenol and 3,4,5-triiodonitrobenzene. The nitro group was replaced by a nitril which was then built up into the alanyl side chain by a series of steps (10). 

Phototransformation of pyridazine 1,2-dioxides sharply contrasts with that of pyridazine 1-oxides. Pyridazine 1,2-dioxide derivatives give 3a,6a-dihydroisoxazolo[5,4- f]isoxazoles (53) through postulated bisiminoxyl radicals. 3,6-Diphenylpyridazine 1,2-dioxide gives, besides the corresponding bicyclic derivative (53), 3-phenylisoxazole (54) and 4,5-diphenyl-furoxan (55). The last two products can be explained by generation of the nitrile oxide from the intermediate (53) with subsequent dimerization to the furoxan (55 Scheme 18) (79T1267). 

Photolysis of 2,3-diphenyl-A -azirine (442) generates benzonitrile ylide (443). Irradiation in the presence of ethyl cyanoformate resulted in a mixture of the oxazoline (444) and the imidazole (445) by 1,3-dlpolar cycloaddition to the carbonyl and nitrile group, respectively (72HCA919). 

In theory, three isoxazolines are capable of existence 2-isoxazoline (2), 3-isoxazoline and 4-isoxazoline. The position of the double bond may also be designated by the use of the prefix A with an appropriate numerical superscript. Of these only the 2-isoxazolines have been investigated in any detail. The preparation of the first isoxazoline, 3,5-diphenyl-2-isoxazoline, from the reaction of )3-chloro-)3-phenylpropiophenone with hydroxylamine was reported in 1895 (1895CB957). Two major syntheses of 2-isoxazolines are the cycloaddition of nitrile A-oxides to alkenes and the reaction of a,/3-unsaturated ketones with hydroxylamine. Since 2-isoxazolines are readily oxidized to isoxazoles and possess some of the unique properties of isoxazoles, they also serve as key intermediates for the synthesis of other heterocycles and natural products. 

Synthetic applications of organosulfur reagents are expanding rapidly. Stable sulfuranes are included for the first time in BIS[2,-2,2-TRIPLUORO-l-PHENYL-l-(TRIFLUOROMETHYL)ETHOXY] diphenyl SULFURANE and DIETHYLAMINOSULFUR TRI-FLUORIDE. The latter is used to transform an alcohol to a fluoride in p-NITROBENZYL FLUORIDE. The direct homologation of a ketone to a nitrile by use of p-TOLYLSULFONYLMETHYL ISOCYANIDE is illustrated in 2-ADAMANTANECARBONITRILE. Reagents with... 

Diphenyl-1//-1,2,4-benzotriazepines 3 are formed in good yield by the cydization of the nitrilium salts 2, which in turn are prepared from the benzenehydrazonyl chloride 1 and nitriles... 

Butyromtnle, 2-benzyl-2-phenyl- [Butane-nitrile, 2-benzyl-2-phenyl-], 55, 94 Butyromtnle, 4-bromo-2,2-diphenyl- [Bu-tanemtnle, 4-bromo-2,2-diphenyl-],... 

Auch Phenyl- und Diphenyl-acetonitril werden vorteilhaft mit Lithiumalanat/Alumini-umchlorid2 (s. ds. Handb., Bd. XI/1, S. 551) oder Aluminiumhydridreduziert3,4. Letz-teres wird besonders in Tetrahydrofuran bei 0° zur selektiven Reduktion ungesattigter Nitrile eingesetzt. 

Auch ungesattigte Nitrile werden mit Chrom(II)-sulfat reduziert. So erhalt man z. B. in quantitativer Ausbeute aus Acrylnitril in Wasser Propansdure-nitril1 bzw. aus trans-2,3-Diphenyl-fumarsaure-dinitril in Dimethylformamid/Wasser (1 2) zu 84% d.Th. eine 1 1-Mischung aus meso- und u,. -2,3-Diphenyl-bemsteinsdure-dinitril. ... 

Der Bis-[2-phenyl-2-cyan-vinyl]-ather (1) wird iiberwiegend zum 2,5-Diphenyl-hexen-(2)-disdure-nitril (III) reduziert. Je nach Kathodenpotential wird zusatzlich 2,5-Diphe-nyl-hexadien-(2,4)-disaure-dinitril (II) bzw. bei 2 V das 2,5-Diphenyl-hexandisaure-dinitril (IV) erhalten. Da es sich hier primar um die Rekombination zweier radikalischer Spaltprodukte des Athers I handelt, ist cine hohe Depolarisator-Konzentration vorteil-haft2 ... 

DiphenyI-athyI)- -dinitril 559 (1,2-Diphenyl-athyIiden)- -dinitril 559 Diphenylmethyl- -athylester-nitril 581 Diphenylmethylen- -athylester-nitril 206, 581 Dodecanoyl- -diathylester 195 Hexyliden-(2)- -dinitril 666 Hydroximino- -diathylester 6/3 Hydroxy- 314... 

Independent work by Schmid93 and by Padwa94 on the photochemistry of 2H-azirines has shown that irradiation of such systems leads in the first instance to the formation of nitrile ylids (nitrilium betaines). Subsequent 1,3-addition to a variety of dipolarophiles affords five-membered heterocycles. These additions take place in a stereospecific and regioselective manner thus, irradiation of the diphenyl-2f/-azirine 117 in the presence of dimethyl maleate leads to the formation of the two isomeric 1-pyrrolines... 

Analogous dienophilic behavior is shown by diphenyl cyclopropenone towards oxazoles235 (isoxazoles behave quite different, see p. 78) giving rise to 3-ethoxy-2,6-diphenyl pyrone-4 (366), which may result from a primary Diels-Alder adduct 365 stabilized by elimination of nitrile ... 

This regioselectivity is practically not influenced by the nature of subsituent R. 3,5-Disubstituted isoxazolines are the sole or main products in [3 + 2] cycloaddition reactions of nitrile oxides with various monosubstituted ethylenes such as allylbenzene (99), methyl acrylate (105), acrylonitrile (105, 168), vinyl acetate (168) and diethyl vinylphosphonate (169). This is also the case for phenyl vinyl selenide (170), though subsequent oxidation—elimination leads to 3-substituted isoxazoles in a one-pot, two-step transformation. 1,1-Disubstituted ethylenes such as 2-methylene-1 -phenyl-1,3-butanedione, 2-methylene-1,3-diphenyl- 1,3-propa-nedione, 2-methylene-3-oxo-3-phenylpropanoates (171), 2-methylene-1,3-dichlo-ropropane, 2-methylenepropane-l,3-diol (172) and l,l-bis(diethoxyphosphoryl) ethylene (173) give the corresponding 3-R-5,5-disubstituted 4,5-dihydrooxazoles. 

I.3.4.2.6. Compounds with Unusual Double Bonds 1,3-Dipolar cycloaddition of l-chloro-2-phenyl-2-trimetkylsilyl-l-phosphaethene with nitrile oxides, followed by elimination of Me SiCl, results in 3,5-diphenyl-l,4,2-oxaphosphazole 190 (356). Chromium, molybdenum, and tungsten pentacarbonyls of 3,5-diphenyl-).3-phosphinins react with nitrile oxides to give the corresponding 1,3-dipolar cycloadducts, at the P = C bond, see 191 (Ar = Ph, Mes) (357). 

Acyl nitroso compounds react with 1, 3-dienes as N-O heterodienophiles to produce cycloadducts, which have found use in the total synthesis of a number of nitrogen-containing natural products [21]. The cycloadducts of acyl nitroso compounds and 9,10-dimethylanthracene (4, Scheme 7.3) undergo thermal decomposition through retro-Diels-Alder reactions to produce acyl nitroso compounds under non-oxidative conditions and at relatively mild temperatures (40-100°C) [11-14]. Decomposition of these compounds provides a particularly clean method for the formation of acyl nitroso compounds. Photolysis or thermolysis of 3, 5-diphenyl-l, 2, 4-oxadiazole-4-oxide (5) generates the aromatic acyl nitroso compound (6) and ben-zonitrile (Scheme 7.3) [22, 23]. Other reactions that generate acyl nitroso compounds include the treatment of 5 with a nitrile oxide [24], the addition of N-methyl morpholine N-oxide to nitrile oxides and the decomposition of N, O-diacylated or alkylated N-hydroxyarylsulfonamides [25-29]. 

Conversely, activated methylene compounds undergo an addition reaction across the C=N bond of imines. For example, benzylic ketones react with benzylidene anilines to from P-aminoketones [35], whereas the analogous reaction of diphenyl-methylene-protected a-amino esters, and nitriles, produces a disastereomeric mixture of the A-protected a,p-diamino esters, and nitriles [36, 37]. 

A domino reaction of 1,1-diphenyl-3,3-dilithioallene (157) with benzonitrile yields both a yellow imidazole (158 R = Ph X = NH) (12%) and a colourless 5-imidazol-5-yl-l,4-dihydropyrimidine (159 R = Ph) (51%), the products, respectively, of the incorporation of three and four nitrile molecules. The proposed mechanism (Scheme 13) involves initial formation of an intermediate (160) that is the product of the interaction of three molecules of benzonitrile with l,l-diphenyl-3,3-dilithioallene (157), which cyclizes to (162 R = Ph) and then eliminates a molecule of benzonitrile to produce (161 R = Ph). Re-addition of benzonitrile at a different locus produces... 

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