Nitrosyl chloride, reaction 4- olefins

The addition of nitrosyl chloride to olefins is accompanied by subsequent reactions if the nitroso group is not tertiary. The nitroso compound may dimerize or rearrange to the more stable oxime tautomer. 

Nitrosyl chloride undergoes addition reactions with many unsaturated organic compounds. It adds to olefinic double bond as follows ... 

The nitrosochlorination of olefins has been known for nearly a century and has materially contributed to the early development of the chemistry of ter-penes [68]. Studies of the scope of the reaction were not undertaken until relatively recently and results appear to be somewhat fragmentary. While 1-olefins such as 1-hexene, 1-heptene, and 1-octene do not react with nitrosyl chloride, the corresponding 2-isomers add the reagent in conformity with Markovnikov s rule as if NO+ and Cl- moieties were involved [69]. 

In a study of the addition of nitrosyl chloride or nitrosyl bromide to norbor-nene and norbomadiene, it was observed that (a) there was no structural rearrangement during the reaction, (b) a cis addition had taken place, (c) nucleophilic solvents such as ethanol or acetic acid were not incorporated in the products. These facts seem to speak against an ionic addition mechanism, while a free radical initiated by NO radicals was considered unlikely since nitric oxide is inactive toward norbomadiene. Therefore a four-center mechanism has been suggested [70], However, when a relatively simple, unstrained olefin such as A9-octalin was subjected to the reaction, only blue, crystalline, monomeric 9-nitroso-10-chlorodecalin was produced. This product had a trans configuration. Thus it is evident that the structure of the olefin has a significant bearing on the steric course of the addition [71]. 

Somewhat analogous to the Reed process is a recent development in which an olefin is reacted with nitrosyl chloride to form a nitrosyl halide, which in turn is converted to a mixture of complex sulfonates by reaction with sodium sulfite (4). These materials are reported to be excellent metal cleaning detergents. 

In a later paper Meinwald concluded that nitrosyl chloride adds cis to strained double bonds, such as that in norbornene, but that it adds trans to unstrained olefins (A -octalin). In accordance with this view of the addition is a report by Hassner on the reaction of cholesteryl acetate (4). Nitrosyl chloride was passed into methylene chloride or carbon tetrachloride until a deep burgundy color developed, the steroid... 

Allhtnigh the rate of reaction of olefins with nitrosyl chloride decreases with ilecreiising number of alkyl substituents, crystalline nitroso chlorides (dimeric) have been obtained even from ethylene and propylene. ... 

The reaction has been used in a three-step conversion of olefins into ketones. For example, nitrosyl chloride is added to cyclooctene (1) and the resulting 2-chlorocyclooctanone oxime3 (2) is then acetylated and treated with chromous acetate at 65° for 16 hours. Cyclooctanone (3) is obtained in 88% yield from (2). 

Addition of nitrosyl chloride (NOC1) to compounds containing C=C or even C—C bonds has been studied for very many cases313a because it is a reaction of preparative importance in, inter alia, terpene chemistry (see, e.g., references 314 and 315). Olefins containing allyl units, as in R—CH2—CH=CH2, form nitrosochlorides (a) less easily than do olefins containing propenyl units as in R—CH=CH—CH3 or those with terminal C=C bonds as in C6H5CH= CH2... 

The kinetics of addition of nitrosyl chloride to a number of olefins have been examined. In chloroform, methyl and phenyl substituents enhance the rate while electron-withdrawing groups (e.g. chlorine) retard it. Such be-haviour would be consistent with electrophilic attack by the dipole NO-CP. The effect of changes in the solvent was not simple, although more polar solvents (nitrobenzene, chloroform) speeded the reaction (compared with toluene or carbon tetrachloride). Methanol appeared to be a remarkably poor reaction medium, perhaps due to interaction with the reactant the low reactivity of nitrosyl chloride in diethyl ether was attributed to strong bonding between the solvent and the incipient NO cation. 

The nitrosation of several amines in aqueous solution by dissolved gaseous nitrosyl chloride has been studied.Provided the amine is in excess, the nitrosation is quantitative, and there is no complication from hydrolysis of the nitrosyl chloride. The reactivity of amines more basic than A -methyl-4-nitroan-iline pKa = 1.49) toward nitrosyl chloride is largely independent of their basicity, and therefore these amines are presumed to react on encounter. Studies on reactions of NOCl with secondary amines " and olefins " have also been reported. The iodine-catalyzed A -nitrosation of piperidine, morpholine, and N-methylpiperazine by NO is independent of the amine and involves a rate-determining formation of nitrosyl iodide, followed by rapid reaction with the amine. 

TFE undergoes free radical addition reactions typical of other olefins. It readily adds Br, Cl, and I, halogen halides IBr and ICl, and nitrosyl halides such as NOCl and NOBr. Additional reactions of chloro-fluoromethanes and chloromethanes in the presence of catalysts like aluminum chloride have been reported [48]. A variety of other compounds such as alcohols, primary amines and ammonia can be reacted with TFE to prepare tetrafluoroethers (HCF CF OR), difluoroacetamide (HCF CONHR) and substituted triazines. Oxygen can be added to TFE to produce polymeric peroxide or TFE epoxide. In the absence of hydrogen, sodium salts of alcohols will react with TFE to yield trifluorovinylethers (ROCF = CF ), which can be homo- and copolymerized. 

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