Nitrogen heterocyde

Allenylimines 186 are not easily accessible, and the most elegant approach is the reaction of alkynylimines 185 with triethylamine to generate 186 in situ the copper ) catalyst which is also present then catalyzes the cycloisomerization to the pyrrole 187 (Scheme 15.59) [120]. The method also is applicable to the imine substructure in 2-alkynylpyridines and related substrates, thus opening up a very elegant access to condensed aromatic nitrogen heterocydes. 

For a recent review of methods for constructing saturated nitrogen heterocydes, see Nadin, A. J. Chem. Soc., Perkin Trans. 1 1998, 3493. 

Najera, C. Lifhiated /Yarn i rioalkyl sulfones as mono and dinudeophiles in the preparation of nitrogen heterocydes application to the synthesis of capsazepine. Tetrahedron 1997,... 

It melts at 39°C and may be purified by vacuum sublimation. The liquid boils at 233°C to give a monomeric vapor in which the Ti—Br distance is 231 pm. Titanium tetrabromide is soluble in dry chloroform, carbon tetrachloride, ether, and alcohol. Like titanium tetrachloride, TiBr4 forms a range of adducts with molecules such as ammonia, amines, nitrogen heterocydes, esters, and ethers. 

Arylamines are commonplace. They are part of molecules with medicinally important properties, of molecules with structurally interesting properties, of materials with important electronic properties, and of transition metal complexes with catalytic activity. An aryl-nitrogen linkage is present in nitrogen heterocydes such as indoles [1, 2] and benzopyr-azoles, conjugated polymers such as polyanilines [3-9], and readily oxidizable triarylamines used in electronic applications [10-13]. The ability of aryl halides and triflates to form arylamines allows a single group to be used as a synthetic intermediate in aromatic carbon-... 

Stoichiometric, palladium-mediated cydization was used in natural product synthesis by Boger a number of years ago, as was noted in the introduction. More recently, an intramolecular palladium-catalyzed amination of a heteroaromatic halide has been used as a step in the synthesis of an a-carboline natural product analogue [193]. As discussed above, the diphenylhydrazone arylation can also be used for nitrogen heterocyde synthesis [183]. 

Wood, A. W., Chang, R. L., Kumar, S., Shirai, N., Jerina, D. M., Lehr, R. E and Conney, A. H. (1986), Bacterial and Mammalian Cell Mutagenicity of Four Optically Active Bay-Region 3,4-Diol-l,2-epoxides and Other Derivatives of the Nitrogen Heterocyde Dibenztc,h]acridine. Cancer Res, 46 2760-2766. 

Regioselective Substitution in Aromatic Six-Membered Nitrogen Heterocydes, 44, 199... 

Lalezari, L, Shafiee, A., Yalpani, M., Selenium-Nitrogen Heterocydes, 24, 109. 

Lyle, R. E., Anderson, P. S., The Reduction of Nitrogen Heterocydes with Complex Metal Hydrides, 6, 45. 

Nitrogen heterocydes can also be prepared by the RCM of unsaturated amines having a diphenyl thioacetal moiety (Table 14.3) [31],... 

Aryl hydrazines c ne precursors uf nitrogen heterocydes such as pyrazolones. which are useful coupling reagents. 

Replacing the hydroxyl group with an amido group provides access to the corresponding nitrogen heterocydes, the 3-pyrrolinones [40]. The example in Equation 1.42 highlights the chemoselectivity of the process since normally the diene moiety of substrate 39 is considered the more reactive functionality. 

E.S.H. El Ashry and A. El Nemr, Synthesis of Naturally Occuring Nitrogen Heterocydes from Carbohydrates. Blackwell FYiblishine,... 

Synthesis of Saturated Nitrogen Heterocydes via Athene, Alkyne, orAllene 9... 

Synthesis of Nitrogen Heterocydes via Intemnediate n-Allylpalladium Complexes... 

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