Chloroamines from amines

The previous sections have dealt with stable C=N-I- functionality in aromatic rings as simple salts. Another class of iminium salt reactions can be found where the iminium salt is only an intermediate. The purpose of this section is to point out these reactions even though they do not show any striking differences in their reactivity from stable iminium salts. Such intermediates arise from a-chloroamines (133-135), isomerization of oxazolidines (136), reduction of a-aminoketones by the Clemmensen method (137-139), reductive alkylation by the Leuckart-Wallach (140-141) or Clarke-Eschweiler reaction (142), mercuric acetate oxidation of amines (46,93), and in reactions such as ketene with enamines (143). 

The required A-chloroamines 9 can be prepared from the corresponding amine by treatment with sodium hypochlorite or A-chlorosuccinimide. 

An Arbuzov reaction of triethyl phosphite with A-chloroamines RNHC1 (R = i-Pr, cyclohexyl or PhCH2), prepared from the corresponding amines and aqueous sodium hypochlorite, leads to the phosphoramides 357 with the elimination of ethyl chloride395. 

Homolytic aromatic amination with electrophilic dialkyl aminyl radical cations is a valuable method for the preparation of aniline derivatives [2e, 10a]. The radical cations (R2HN+ ) are generally prepared from the corresponding A-chloroamines... 

Nelson s detailed investigation of one-electron oxidation of bicyclic amines and hydrazines continues CV studies show that /V -diacyl-hydrazines (19)30a and azabicyclooctanes (20a)30b gjVe long-lived radical cations comparison has been made between ease of electron loss and N inversion barriers in (20b) and related N-chloroamines 30c studies of the nitroxides (21) and related compounds show that ff-coupied transmission of positive charge from N to the CO in the radical cation is unimportant. 30d... 

Amino alcohols, which are conveniently made from oxiranes with ammonia or amines, react with thionyl chloride to give chloroamines, which can be cyclized to aziridines by alkali hydroxide (Gabriel 1888). 

Homolytic aromatic substitution can also be performed with electrophihc het-eroatom-centered radicals. The radical amination of arenes with electrophilic diaUcyl aminyl radical cations represents a valuable method for the preparation of aniUne derivatives [2e, 111a]. The radical cations (R2HN ) are generally prepared from the corresponding N-chloroamines in an acidic medium, using catalytic amounts of a metal salt [Fe(II)-, Ti(III)-, Cu(I)- and Cr(II)-salts]. The reaction func-... 

Further examples of the Ritter reaction(cf. section IV.B) are provided by the many substituted olefins that may be protonated to ve carbonium ions which can be intercepted by hydrogen cyanide or organic nitriles cyanogen chloride can also be used as intercepting species , but offers no advantages. Mixtures of the two possible amides, and hence amines, are to be expected from non-terminal alkenes and from such olefinic compounds as oleic acid Olefins may also be converted to amines with yields of up to 60%, by hydroboration and subsequent reaction of the organoborane with chloroamine in alkaline solution or preferably with hydroxylamine-0-sulphonic acid in diglyme (reaction 86) The reaction is applicable... 

Protonated Amino Radicals. The reac.tion of hydroxyl amine with TiCl, in aqueous, acidic methanol results in the formation of the simplest protonated amino radical, NH,T. This radical added readily to butadiene and to simple olefins to form products which were the result of coupling of the intermediate B-aminoalkyl radicals ( ). The addition reactions of protonated di-alkylamino radicals were described in a series of elegant papers by Neale and his co-workers (5-10). The radicals were generated from the appropriate N-chloroamines in presence of the unsaturated system. The most effective acid solvent combination was found to be 4M sulfuric acid in glacial acetic acid, but other acid/solvent combinations were also used. The reactions proceeded by chain mechanisms, which were initiated by light or by... 

The cyclization of chloroamines in concentrated sulphuric acid (Hofmann-Loffler-Freytag method) has been known for a number of years. Photocyclization in the presence of triethylamine of a chloroamine prepared in situ from an amine and N-chlorosuccinimide has now been found to produce a similar result and is exemplified in Scheme 121. The reaction is probably limited to the preparation of... 

Organoboranes derived from terminal olefins or relatively unhindered olefins are readily converted to the corresponding amine by treatment with chloroamine or hydroxylamine-O-sulfonic acid [16]. 

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