Benzyl chloride terminator

Functionalization of these reactive anionic chain ends can be achieved by a variety of methods all based on the general concepts of carbanion chemistry. For example, reaction with C02 or succinnic anhydride leads to the carboxy terminated derivatives [10], while hydroxy-terminated polymers can be easily obtained by reaction with ethylene oxide (Scheme 3) [11]. In select functionalization reactions, such as alkylation with p-vinyl benzyl chloride, the nucleophilicity of the carbanionic species may be necessary and this can be achieved by reaction of the chain end with 1,1-diphenylethene followed by functionalization [12,13]. 

The termination of polymerization of substituted ethylenes is by an internal Friedel-Crafts reaction, whereas that of the substituted benzyl chlorides is by the reaction with chloride ions. 

If the activated aromatic compound reacts with a mixture of formalin, concentrated hydrochloric acid, and ZnCl2, the result is a so-called chloromethylation (Figure 5.29). The stable reaction product is a primary benzyl chloride. This reaction is initiated by an electrophilic substitution by protonated formaldehyde it is terminated by an SN1 reaction in which a chloride ion acts as the nucleophile. 

Functionalized monomers are sometimes regarded as polymerizable surfactants. Vinyl or allyl monomers are reacted with ethylene oxide (EO), propylene oxide (PO) or butylene oxide (BO) in a sequential or random addition mode. The terminal hydroxyl group can be optionally reacted with methyl or benzyl chloride to produce Williamson ethers (if the hydroxyl group has to be deactivated) or are further sulfated to deliver electrosteric stabilization. 

Derivatives from pure ethylene oxide are water soluble and result in silicon polyols with water solubility or dispersibility. Propylene oxide and even more butylene oxide allow for more compatibility with organic media, e.g. butylene oxide gives compatibility with organic oils. Depending upon the demanded balance of hydrophilicity/hydrophobicity, different proportions and order of addition of the alkoxide can be used. In certain instances blocking of the terminal hydroxyl group maybe required, e.g. by reaction with methyl or, less commonly, benzyl chloride. 

Hyperbranched polymers may be prepared by the self-condensing vinyl polymerization (SCVP) [257] of AB star monomers by a controlled free radical process, such as ATRP [258]. The result, under certain conditions, is a highly branched, soluble polymer that contains one double bond and, in the absence of irreversible termination, a large quantity of halogen end groups equal to the degree of polymerization which can be further functionalized [87] (Fig.35). Two examples explored in detail by ATRP are vinyl benzyl chloride (VBC, p-chlo-romethylstyrene) [258] and 2-(2-bromopropionyloxy)ethyl acrylate (BPEA) [259-261] both depicted in Fig. 35. Several other (meth)acrylates with either 2-... 

Write reactions to show the type of end group that will result from the use of each of the following reagents to terminate butyllithium initiated living polymers of styrene in THF (a)Ethyl benzoate (b) benzyl chloride (c) bromoaniline (d) phthalic anhydride (e) phosgene (f) carbon disulfide. 

Researchers van der Broeke and coworkers[" created perfluoro-functionalized poly(propyleneimine) dendrimers (23 Fig. 4) and demonstrated their potential as phase-transfer catalysts in supercritical carbon-dioxide-water mixtures and as anionic species extractants. The dendrimers were accessed via reaction of perfluorinated, linear alkyl acid chlorides with the terminal amines. Extraction of perinanganate or dichromate from aqueous to CO2 solution was described as rather low, whereas their use as phase-transfer catalysts in a halogen exchange reaction [benzyl chloride to benzyi bromide (24)] resulted in high rates of conversion. 

Theoretical calculations of the stabilities of various hexahaloantimonates have shown that the rupture of an Sb-Cl bond requires more energy than that of an Sb-Br bond, and the relative positions of chlorine and bromine atoms within a mixed halogen counterion can affect the ease of bond breakage. Model compound studies of the reaction between p-methyl benzyl chloride, triethyl aluminium, and 2,4,4-trimethylpent-l-ene (dimeric isobutylene) indicated that the principal chain termination reactions involve hydridation and ethylation resulting from counterion decomposition. ... 

Very recently, Jiang et al. developed a palladium-catalyzed three-component coupling reaction for the synthesis of 1,3-butadienes that involves the sequential formation of a C(sp )—C(sp ) bond and a C(sp )- (sp ) bond from a benzyl chloride, a terminal alkyne, and a monosubstituted alkene [32],... 

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