| 摘要 |
Polymers or copolymers comprising recurring structural units of the formula -CH2-C(R)(G)-, where R is a hydrogen atom or a monovalent hydrocarbon radical, and G is -B(OH)2 or -B(OR1)3 M or -B(OR1)2, R being an alkyl radical of 1 to 4 carbon atoms and M being MgCl, MgBr, Li, K or Na, are prepared by polymerization or copolymerization of a compound of the formula CH2=C(R)G. In an example, dimethyl ethylene boronate polymerizes quite readily at or below room temperature to give a transparent polymer having the repeating unit -CH2-CH(B(OCH3)2)-.ALSO:The invention comprises b -unsubstituted vinyl boron compounds having the formula CH2 = C(R)G, where R is a hydrogen atom or a monovalent hydrocarbon radical and G is - B (OH)2, - B(OR1)2 or - B(OR1)3M, R being an alkyl radical comprising from 1 to 4 carbon atoms and M being MgCI, MgBr, Li, K or Na. The compounds of the formula CH2 = C(R) - B(OR1)3 M may be prepared by reacting a boric acid ester with a metalated vinyl compound CH2 = C(R)M. A b -unsubstituted vinyl boronic acid or its ester may be obtained by reacting the corresponding compound CH2 = C(R) - B(OR1)3 M in a non-aqueous medium with an anhydrous acid or with an anhydrous active-halogen containing compound, e.g. benzoyl chloride, respectively. Examples describe the preparation of ethylene- and isopropeneboronic acids, chloromagnesium trimethoxyvinylboron, lithium triisopropoxy isopropenylboron and dimethyl ethyleneboronate. The novel products polymerize readily (see Group IV(a)). |
