Preparation and reactions of polymeric Grignard compounds

Burgess, F.J.; Richards, D. H.

doi:10.1016/0032-3861(76)90179-8

Cited by 42 publications

(15 citation statements)

References 7 publications

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“…The same research group also reported the synthesis of end-functionalized polystyrenes with bromomethylphenyl groups by reaction of either polystyryllithium or polystyrylmagnesium bromide with α,α‘-dibromo- m -xylene. − It was again observed that the coupling to produce dimer occurred during the reactions. The maximum yield never exceeded 77%.…”

Section: Resultsmentioning

confidence: 95%

“…However, these reactions, in general, proceeded competitively with the Wurtz-type coupling reactions to yield considerable amounts of dimeric byproducts. Richards and co-workers were successful in reducing the degree of coupling by transforming polystyryllithium into the corresponding Grignard reagent . In the reaction with bromine, for example, the yield of brominated polystyrene was increased from 58 to 93% yield.…”

Section: Resultsmentioning

confidence: 99%

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Synthesis of Well-Defined Functionalized Polystyrenes with a Definite Number of Chloromethylphenyl Groups at Chain Ends or in Chains by Means of Anionic Living Polymerization in Conjunction with Functional Group Transformation

Hirao

Hayashi

1999

Macromolecules

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The syntheses of well-defined polystyrenes functionalized with a definite number (from one to four) of chloromethylphenyl groups at the chain ends or in the chains by means of anionic living polymerization in conjunction with functional group transformation are described. The synthetic method involves the introduction of anion-stable methoxymethylphenyl or tert-butyldimethylsilyloxymethylphenyl groups at the chain ends or in the chains and subsequent transformation reactions of these groups into chloromethylphenyl groups with BCl3. It is also possible to transform the tert-butyldimethylsilyloxymethylphenyl group into bromomethylphenyl and iodomethylphenyl groups by treatment with Me3SiCl−LiBr, and Me3SiCl−NaI, respectively. Furthermore, the synthesis of well-defined polystyrenes having two, four, and six methoxymethylphenyl and six chloromethylphenyl termini via a new iterative approach using 3-(tert-butyldimethylsilyloxy)-1-propyllithium is described. It involves repeated chemical transformations at the chain end from tert-butyldimethylsilyloxybutyl, bromobutyl, and methoxymethylphenyl groups to the chloromethylphenyl group. At each stage in the iteration, the number of chloromethylphenyl groups doubles. The resulting polymers all, after HPLC fractionation in some cases, possessed well-controlled molecular weights and narrow molecular weight distributions. Their functionalities were nearly quantitative in all cases.

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Section: Resultsmentioning

confidence: 95%

Section: Resultsmentioning

confidence: 99%

Synthesis of Well-Defined Functionalized Polystyrenes with a Definite Number of Chloromethylphenyl Groups at Chain Ends or in Chains by Means of Anionic Living Polymerization in Conjunction with Functional Group Transformation

Hirao

Hayashi

1999

Macromolecules

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“…For example, direct halogenations of the polystyryl anion with both bromine and iodine were reported. These reactions proceeded competitively with coupling reactions to yield considerable amounts of dimeric side products. , The yield of brominated polystyrene was increased to some extents by converting polystyryllithium to the corresponding Grignard reagent . Even in this case, the dimer formation by coupling could not be completely suppressed.…”

Section: Introductionmentioning

confidence: 99%

Synthesis of End-Functionalized Polymers by Means of Living Anionic Polymerization. 8. Reactions of Living Anionic Polymers with α,ω-Dihaloalkanes

1997

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In order to prepare well-defined polymers with halogen end groups, anionic living polymers of isoprene and styrene were allowed to react with excess amounts of α,ω-dihaloalkanes in THF at −78 °C. The monosubstitution reactions of 1,3-dichloropropane with these anionic living polymers proceeded cleanly to afford quantitatively the polymers with chlorine end groups that possessed controllable molecular weights and narrow molecular weight distributions. On the other hand, the reactions of the anionic living polymers with either α,ω-dibromoalkanes or α,ω-diiodoalkanes proceeded competitively with side reactions leading to dimer formation of the starting living polymers. Thus, the bromine- and iodine-terminated polymers were obtained in 12−93% yields along with undesirable dimers. As side reaction candidates, we speculated on metal−halogen interchange and/or single electron transfer pathways followed by coupling reactions between the reaction intermediates generated by both pathways. By end-capping the polystyryl anion with 1,1-diphenylethylene, one could almost suppress the dimer formation, and the end-functionalized polystyrenes with bromine and iodine were successfully obtained in more than 95% yield.

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“…Υπάρχουν δύο γενικές προσεγγίσεις μέσω των οποίων μπορούν να παρασκευαστούν ακροδραστικά πολυμερή με ανιοντικό πολυμερισμό.Η πρώτη περιλαμβάνει τη χρήση απαρχητών πολυμερισμού που φέρουν τη δραστική ομάδα 74 και η δεύτερη ηλεκτρονιόφιλων αντιδραστηρίων που αντιδρούν με τις ζωντανές πολυμερικές αλυσίδες 72 • 75 . Με τους δϋο αυτούς τρόπους έχουν παρασκευαστεί μακρομόρια με πολλές δραστικές ομάδες όπως: υδροξύλιο 76 - 77 , καρβοξύλιο [78][79][80] , αλογόνα 81 • 82 , αμίνες 83 ' 85 , σουλφιδρίλιο 86 91 . Κατόπιν με κυκλοπροπανοσουλτόνη μετέτρεψε τις διμεθυλαμινομάδες σε ιοντικά δίπολα.…”

Section: ευχαριστιεςunclassified

Γραμμικα Και Αστεροειδη Πολυβουταδιενια Με Ακραιες Πολικες Ομαδες. Συνθεση-Χαρακτηρισμος-Ιδιοτητες Σε Αραια Διαλυματα

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Preparation and reactions of polymeric Grignard compounds

Cited by 42 publications

References 7 publications

Synthesis of Well-Defined Functionalized Polystyrenes with a Definite Number of Chloromethylphenyl Groups at Chain Ends or in Chains by Means of Anionic Living Polymerization in Conjunction with Functional Group Transformation

Synthesis of Well-Defined Functionalized Polystyrenes with a Definite Number of Chloromethylphenyl Groups at Chain Ends or in Chains by Means of Anionic Living Polymerization in Conjunction with Functional Group Transformation

Synthesis of End-Functionalized Polymers by Means of Living Anionic Polymerization. 8. Reactions of Living Anionic Polymers with α,ω-Dihaloalkanes

Γραμμικα Και Αστεροειδη Πολυβουταδιενια Με Ακραιες Πολικες Ομαδες. Συνθεση-Χαρακτηρισμος-Ιδιοτητες Σε Αραια Διαλυματα

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