Phenyl isonitrile

Chloroform is readily recognised by its odour and by the phenyl isonitrile test. It is found in the first fractions distilled. 

Mit Diboran entsteht dagegen aus Phenyl-isonitril in der Kalte das cyclische Dimere... 

Among binucleophiles used in this reaction 3-amino-l,2,4-triazole and 2-aminothiazole were also selected. However, in the reaction of the latter with phenyl isonitrile and formaldehyde, only the moderate yields of the target product 101 were observed by the LC-MS analysis of the crude reaction mixture. In case of aminotriazole, any product of the reaction was failed to be detected (Scheme 47). 

Palladium-mediated cydization based on the reactivity of o-alkynyl or alkenyl-phenyl isonitriles have been developed [105]. On the basis of their earlier studies on the three-component synthesis of allyl aryl cyanamides [106], Yamamoto and co-workers reported a palladium-catalyzed three-component coupling reaction of 2-alkynylisocyanobenzenes 122 with allyl methyl carbonate and trimethylsilylazide leading to N-cyanoindoles 125 [107]. One of the key steps of the proposed mechanism is the formation of 7i-allylpalladium carbodiimide 123 and its isomerization to rc-allylpalladium cyanamide complex 124 (Scheme 8.50). 

Since 1948-50, by using as reactants isonitriles, phosphorus trihalides, and tertiary phosphines, we have gained important insight into the dependence of reactions of metal carbonyls with bases upon the nature of the ligand. Organophosphines were introduced into carbonyl chemistry even prior to 1948 by Reppe and Schweckendiek (7). In general, these ligands react only by substitution of CO, and do not cause disproportionation. Thus nickel carbonyl frequently reacts with complete displacement of carbon monoxide, as we were first able to demonstrate in the reaction with phenyl isonitrile (8). 

Suggest structures for the intermediates formed in the radical cascade reaction of 8 with phenyl isonitrile. 

The simultaneous construction of the B and C rings leading to compound 33 was accomplished by a radical cascade reaction. The mechanistic details of this cascade are summarized in Scheme 6, where the reaction of 34 with phenyl isonitrile (8) is shown [12]. First, a trimethylstan-nyl radical, derived from hexamethyldistannane, attacks the C-Br bond of 34. The resulting pyri-done radical 35 reacts intermolecularly with the isonitrile 8 to yield the radical intermediate 36. 

The reaction has also been carried out under alkaline conditions, with hydroxide in aqueous dioxane. The mechanism here involves nucleophilic attack by hydroxide at the carbon atom. An intramolecular addition of an alkyne (in an ortho alky-nyl phenyl isonitrile) to the carbon of an isonitrile occurred with heating in methanol to give quinoline derivatives. ... 

Finally, siliranes have been allowed to react for the first time with isocyanides. Phenyl isonitrile 47 and /7-nitrophenyl isonitrile 48 underwent insertion into the Si-C bond at room temperature with formation of the silacyclobutanimines 49-51 [17]. 

The reagent (60) generated in situ from the action of LiBu on phenyl isonitrile and r-butyl dichlorophosphine or methyl dichloroarsine gives the 3/7-1,3-benzazaphosphole/arsole (61) which is converted to the 1/7-1,3-benzazaphosphole/arsole (62) by flash vacuum pyrolysis (Scheme 6)... 

BusSnH-mediated intramolecular arylations of various heteroarenes such as substituted pyrroles, indoles, pyridones and imidazoles have also been reported [51]. In addition, aryl bromides, chlorides and iodides have been used as substrates in electrochemically induced radical biaryl synthesis [52]. Curran introduced [4-1-1] annulations incorporating aromatic substitution reactions with vinyl radicals for the synthesis of the core structure of various camptothecin derivatives [53]. The vinyl radicals have been generated from alkynes by radical addition reactions [53, 54]. For example, aryl radical 27, generated from the corresponding iodide or bromide, was allowed to react with phenyl isonitrile to afford imidoyl radical 28, which further reacts in a 5-exo-dig process to vinyl radical 29 (Scheme 8) [53a,b]. The vinyl radical 29 then reacts in a 1,6-cyclization followed by oxidation to the tetracycle 30. There is some evidence [55] that the homolytic aromatic substitution can also occur via initial ipso attack to afford spiro radical 31, followed by opening of this cyclo-... 

The potent antitumor agents camptothecin (11) and its derivatives are targets of extensive synthetic activities. [7] A major contribution to this research area came from the laboratory of D. R Curran [3] in Pittsburgh with a total synthesis of camptothecin relying on radical chemistry. In the key step of his synthesis (Scheme 2) the iodoalkyne 9 was allowed to react with phenyl isonitrile to provide the target compound 11. 

The reaction is carried out under Ng a large excess of phenyl isonitrile is desirable. Six grams of chromium (II) acetate Crg(CHaCOO)4 2 HgO is suspended in 40 ml. of methanol, and a solution of 20 g. of isonitrile in 10 ml. of methanol is added. After about one hour, well-formed garnet-red crystals separate from the deep black-red solution. The precipitate is filtered, washed with some methanol, and dried. 

In 1992, novel methodology for the construction of the camptothecin molecule was reported by Curran et al [57-59]. They have applied a novel (4 + 1) radical annulation reaction to the construction of rings B and C of camptothecin. Reaction of A-propargylpyridone (11) with phenyl isonitrile and hexamethylditin under irradiation with a sunlamp gave the tetracyclic compound (12), which was readily converted to (20RS)-camptothecin (13) (Scheme 2.1) using Danishefsky s procedure [60]. The synthesis of key com-... 

A mixture of phenyl isonitrile and cyclohexanone allowed to react 1 hr. at 0 with BFg-ether 3,3-pentamethyleneindolenine-2-carboxanilide. Y 40%. B. Zeeh,... 

---