1,1-Diphenylethylene, addition sodium

I O Addition compounds. the organosodium compounds discussed so far can be considered as derived from hydrocarbons by the substitution of sodium for hydrogen, e.g. PhaCH— -PhaCNa. Various organosodium compounds may also be formed by addition of sodium to hydrocarbons these are of two types, those that could also be regarded as sodiiun salts of hydrocarbons and those that cannot. For example, 1,1-diphenylethylene adds sodium by a one-electron transfer, and this is followed by dimerization ... 

Surprisingly it was reported that when potassium cyanate is substituted for sodium cyanate the yields of carbamates are reduced to less than 5 %. The reason for this drastic effect is not known at this time. In addition, the use of other alkali or alkaline metal cyanates in this reaction has not been investigated. The Loev [28] procedure appears applicable to the synthesis of carbamates from primary, secondary, and tertiary alcohols (2 hr reaction time affords 60-90% yields), cyclic and acyclic 1,3-diols, phenols, oximes, ald-oximes, and ketoximes, and primary, secondary, and tertiary mercaptans. Carbamates could not be obtained from diphenylethylcarbinol (dehydrated to 1,1-diphenylethylene) or trichloro- and trifluoromethylcarbinols. 

The anti addition of diethyl 7V,Ar-dibromophosphoramidates to acyclic and cyclic alkenes was achieved in the presence of boron trifluoride, which makes the ionic dissociation of the N —Br bond more labile94,9s. After reduction of the initial /J,lV-dibromo adducts with sodium bisulfite, the /i-bromo-A -hydrophosphoramides 3 precursor of / -bromo amine hydrochlorides 4 were obtained (Table 4). However, a mixture of diastereomers was obtained from (Z)-l-phenyl-l-propene and (E)- and (Z)-l,2-diphenylethylene. Direct assignment of stereochemistry by H NMR of the phosphoroamidates derived from 2-butenes was not possible. Detailed analysis is, however, possible for the H-NMR spectra of the /J-bromo amine hydrochlorides. As determined by 31P NMR spectroscopy all additions to unsymmetrical aliphatic alkenes were not regiospecific. The /f-bromo amine hydrochlorides were converted to 1,2-diamines95. 

Other -lactones. The lactones of yohimbic acid and malic acidi give the expected reactione, but the lactone of 3-hydroxy-3-methylbutyrio add, which is somewhat less stable in water, only gives addition products with the alkali halides in low yield. The addition of sodium chloride, bromide and iodide to the lactone of 2,2-diphenylhydtaoryhe acid docs not give the corresponding add but rather diphenylethylene in a yield of 6,54, and 86%, respectively ... 

An early report of the beneficial influence of 1,1-diphenylethylene (DPE) on the yields of alkylaryl ether obtained in the reaction of diaryliodonium salts with sodium alkoxides showed that radical chain reactions compete efficiently with the 0-arylation reaction. By contrast, addition of diphenylpicrylhydrazyl, a stable free radical species, had no significant influence on the yields of products obtained in e absence of additives. In this case, the 0-arylation reaction was considered to be a direct nucleophilic aromatic substitution reaction, without the involvement of any transient covalent intermediate. (Table 2.11)... 

Such a mechanism was unlikely as addition of an external trap, 1,1-diphenylethylene, had no effect on the course of the arylation of p-ketoesters.i l A second approach involved the use of an internal trapping system which had been successfully used in the study of the radical reactions of arenediazonium salts.The internal trap containing reagent, ( rf/io-allyloxyphenyl)lead triacetate (94), can be easily prepared from the corresponding boronic acid. 2 Reaction with various types of nucleophiles, such as ethyl 2-oxocyclopentanecarboxylate (86), mesitol (36), the sodium salt of nitropropane, iodide and azide always afforded the C-arylation products in high yield. No trace of the 3-substituted dihydrobenzofurans, expected in a mechanism involving the intermediacy of free radicals, could be detected. 

Boileau, Kaempf, Schue and coworkers have studied the cryptate mediated anionic addition polymerization of several systems including ethylene oxide [38], propylene sulfide [39-40], isobutylene sulfide [40], isoprene [38], methyl methacrylate [38], hexamethyl trisiloxane [40], e-caprolactone [41], styrene [38, 40, 41], ct-methylstyrene [41], 1,1-diphenylethylene [41] and /3-propiolactone [42]. The polymerization of the latter compound induced by dibenzo-18-crown-6 complexed sodium acetate has also been reported [43]. In general, it was found that the polymer-... 

This lack of copolymerization reactivity of DPE was also observed for the copolymerization of 1,1-diphenylethylene and isoprene [125, 134]. As shown in Table 7, when isoprene was copolymerized with DPE in benzene using n-butyllithium as initiator, the monomer reactivity ratio was 37, which indicates that the addition of isoprene to the isoprenyllithium chain end is 37 times faster than the addition of 1,1-diphenylethylene. The unreactivity of isoprenyl carbanions toward DPE is unique to lithium the monomer reactivity ratios for isoprene in benzene were 0.38 and 0.05 with sodium and potassium as the counterions [125, 134]. When THE was used as the solvent at 0°C, ri decreased to 0.11 with lithium as counterion. 

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