Acetylenic amines, alkylation

Protonated /V-chloroalkyl amines under the influence of heat or uv light rearrange to piperidines or pyrroHdines (Hofmann-Lriffler reaction) (88). The free-radical addition of alkyl and dialkyl-/V-chloramines to olefins and acetylenes yields P-chloroalkji-, P-chloroalkenyl-, and 8-chloroalkenylamines (89). Various N-hiomo- and N-chloropolyfluoroaLkylarnines have been synthesized whose addition products to olefinic double bonds can be photolyzed to fluoroazaalkenes (90). 

Me3SiI, CH2CI2, 25°, 15 min, 85-95% yield.Under these cleavage conditions i,3-dithiolanes, alkyl and trimethylsilyl enol ethers, and enol acetates are stable. 1,3-Dioxolanes give complex mixtures. Alcohols, epoxides, trityl, r-butyl, and benzyl ethers and esters are reactive. Most other ethers and esters, amines, amides, ketones, olefins, acetylenes, and halides are expected to be stable. 

The synthesis can be conducted both in solution and without solvents. The reaction in solvent (e.g., methanol, ethanol, dioxane, dimethylformamide) is recommended for volatile 1,3-diynes and amines in this case the pyrroles are purer and the yield is higher. With disubstituted diacetylenes, ammonia and primary alkyl- and arylamines produce 1,2,3-trisubstituted pyrroles under the same conditions (65CB98 71MI1). Since disubstituted diacetylenes are readily obtained by oxidative coupling of acetylenes (98MI2), this reaction provides a preparative route to a wide range of pyrroles. 

A variety of triazole-based monophosphines (ClickPhos) 141 have been prepared via efficient 1,3-dipolar cycloaddition of readily available azides and acetylenes and their palladium complexes provided excellent yields in the amination reactions and Suzuki-Miyaura coupling reactions of unactivated aryl chlorides <06JOC3928>. A novel P,N-type ligand family (ClickPhine) is easily accessible using the Cu(I)-catalyzed azide-alkyne cycloaddition reaction and was tested in palladium-catalyzed allylic alkylation reactions <06OL3227>. Novel chiral ligands, (S)-(+)-l-substituted aryl-4-(l-phenyl) ethylformamido-5-amino-1,2,3-triazoles 142,... 

All the above-mentioned initiators are very sensitive towards substances with active hydrogen. Care must therefore be taken to exclude acids, water, thiols, amines, and acetylene derivatives. Oxygen, carbon dioxide, carbon monoxide, carbonyl compounds, and alkyl halides which can react with the initiator, also interfere with the reaction. Careful purification and drying of the starting materials and apparatus is, therefore, absolutely essential, especially when dealing with living polymers (see Example 3-19). 

Sommelet, 30, 67 Alizarin indicator, 37, 33 N-Alkyl amines, formation of, 38, 29 Alkylation, of acetylene, 30, 15... 

The corrinoid-mediated reduction of polyhaloethenes has been the subject of a recent study, which reports reaction via homolytic C-halogen bond fission. The elimination of a further halogen radical affords haloalkynes, which lead to acetylene itself.56 The electron transfer-induced reductive cleavage of alkyl phenyl ethers with lithium naphthalenide has been re-examined in a study which showed that it is possible to reverse regioselectivity of the cleavage (i.e. ArOR to ArH or ArOH) by introduction of a positive charge adjacent to the alkyl ether bond.57 A radical intermediate has been detected by ESR spectroscopy in the reduction of imines to amines with formic acid58 which infers reacts takes place via Lukasiewicz s mechanism.59... 

Alkyl halides react with nucleophiles, reagents that can supply an electron pair to form a covalent bond, to give a product in which the nucleophile takes the place of the halogen. Table 6.1 gives fifteen examples of such nucleophilic substitution reactions, which can be used to convert alkyl halides to alcohols, ethers, esters, amines, thiols, alkyl cyanides, or acetylenes. 

The work of Nazarov on vinyl ethynyl carbinols involves condensation of vinylacetylene with ketones in the presence of caustic potash and also their conversions, many of which are catalytic in nature. A review of his work involving polymerization, isomerization, hydrogenation, and other conversions was published by him (252). Hydration of divinylacetylenes in methanol solution in the presence of mercuric sulfate and sulfuric acid gave vinyl alkyl ketones. These can be reacted with hydrogen sulfide, amines, etc., to yield heterocyclic compounds. Substituted vinyl alkyl ketones underwent spontaneous cyclization to cyclopentenones. Nazarov summarized a decade of this research in this field in 1951 (253). His general review of organic syntheses based on acetylene is also of interest in this connection (254). 

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