Imidoyl compounds

Referring to the initial formation of imidoyl compounds in the course of the acid-catalyzed ketone-nitrile reaction95,96,98 Garcia and coworkers97 described a new one-pot synthesis of 1-substituted 3-arylisoquinolines 149 from deoxybenzoins 148 and nitriles (equation 49). The authors used two procedures applying either phosphorus oxychloride at reflux or phosphorus pentoxide at room temperature. 

Organogold carbene compounds [Au(carbene)(CN) j iR ] can be obtained from com-plexed cyanides [Au(CN)m(C6F5) ] (n = 1 or 3, m = 1 and n = m = 2) by sequential alkylation (to form isocyanide complexes) and nucleophilic attack of amine" . Gold(III) diisocyanides [Au(CNR)2(CgF5)2]+ (R = Ph or p-tolyl), which can also be obtained by isocyanide substitution of ether in [Au(C6F5)2(OEt2)2] > react with hydrazobenzene NH(Ph)NHPh and hydrazine or phenyUiydrazine according to the reactions in Scheme 32 to furnish cyclic bis(carbene) and cyclic carbene-imidoyl compounds . ... 

In a later paper Speziale and Smith 109) investigated the reaction of trivalent phosphorus compounds with N-monosubstituted a-trichloro-acetamides and a-trichloroacetamide. The products were imidoyl chlorides (129) and dichloroacetonitrile (130), respectively. The intermediacy of enamines (131) was assumed. For the monosubstituted amides the enamine... 

This group of compounds is represented by A-methyl-2,5-diphenyl-l-aza-6-oxa-6fl-tellurapentalene 94 which was prepared in low yield (11%) by coupling an imidoyl chloride 95 with a tellurenyl chloride 96 in acetonitrile solution containing 2,6-lutidine (87MI2). 

It has been shown that the imidoyl chloride moiety of 2(lff)-pyrazinones can imdergo an easy addition/elimination reaction with alkyl amines [24], while reactions with anilines proceed under harsher conditions. Ullmann coupling [109-113] of 2(lff)-pyrazinones with substituted anilines could open the way to the libraries of physiologically active compounds useful in inhibiting HIV replication [7]. Polymer-bound pyrazinone was successfully... 

Treatment of N-benzoyl-L-alanine with oxalyl chloride, followed by methanolic triethylamine, yields methyl 4-methyl-2-phenyloxazole-5-carboxylate 32 <95CC2335>. a-Keto imidoyl chlorides, obtained from acyl chlorides and ethyl isocyanoacetate, cyclise to 5-ethoxyoxazoles by the action of triethylamine (e.g.. Scheme 8) <96SC1149>. The azetidinone 33 is converted into the oxazole 34 when heated with sodium azide and titanium chloride in acetonitrile <95JHC1409>. Another unusual reaction is the cyclisation of compound 35 to the oxazole 36 on sequential treatment with trifluoroacetic anhydride and methanol <95JFC(75)221>. 

The synthesis of 1,3-selenazoles from A -phenylimidoyl isoselenocyanates has been reported. N-phenylimidoyl isoselenocyanates 94 are prepared from N-phenylbenzamides 92. Treatment of 92 with thionyl chloride affords N-phenylbenzimidoyl chlorides 93, which yield imidoyl isoselenocyanates 94 on reaction with potassium isoselenocyanate. The imidoyl isoselenocyanates 94 were transformed into selenoureas 95 with either ammonia or primary or secondary amines. Reaction of 95 with an activated bromomethylene compound such as bromoacetophenone in the prescence of a base gave the 1,3-selenazole 97 via the salt 96 <00HCA1576>. 

The 2,3-dioxo-6-thioxo-2,3,5,6-tetrahydro-l/7-imidazo[l,2-A]pyrazole 393 and 5,6-dioxo-2,3-dihydro-l//-imidazo[l,2- ]-imidazole 395 were synthesized by condensation of the respective 5-amino-3-thioxo-2,3-dihydro-pyrazole 392 and 2-aminoimidazoline 394 compounds with either oxalyl dichloride or diethyl oxalate in moderate to poor yields (Equations 178 and 179) <1995JPR472, 2002EJM845>. These cyclizations can suffer from various side reactions such as expulsion of CO, polymerization, or formation of open-chain products. To solve these problems, reagents such as oxalic acid bis-imidoyl- and bis-hydrazoylchlorides 397 and 400 as well as 2,3-dichloroquinoxalines 403... 

Imidoylstannanes, R13SnCR2=NR3, can be prepared from the reaction of stannyllithium compounds with the corresponding imidoyl chlorides (C1CR2=NR3 R2 and R3 = aryl),163 or, more generally, from the reaction of an acylstannane with an amine.164 The imidoylstannane can then be reduced to an a-aminostannane (Equation (49)).165... 

Intensive investigations have been directed recently to group-transfer imidoylation of organotellurium compounds with isonitriles. " ... 

The described imidoylation of a-acyl radicals deserves great interest since a-acyl compounds are not only versatile building blocks but also exhibit several biological activities. ... 

Stannous chloride is used most frequently for the reduction of nitro compounds [177, 178, 179] and of quinones [180, 181], It is also suitable for conversion of imidoyl chlorides [182] and of nitriles [183] to aldehydes, for transformations of diazonium salts to hydrazines [184], for reduction of oximes [f[Pg.30]

For compound 22, X-ray analysis demonstrates that the dioxane ring adopts the chair conformation and that the imidoyl amino group prefers an axial conformation <2002T2621>. For (l,4-benzodioxin-2(3//)-yl)methyl sulfamic acid ester 21, the conformation of the dihydrodioxin ring is close to an ideal half-chair and for 1,2,4,6,7,9-hexafluoro-... 

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