Scope and Regioselectivity of Iridium-Catalyzed C鈥揌 Borylation of Aromatic Main-Chain Polymers

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• 作者：Ying Chang ; Hanniel H. Lee ; Se Hye Kim ; Tae Soo Jo ; Chulsung Bae
• 刊名：Macromolecules
• 出版年：2013
• 出版时间：March 12, 2013
• 年：2013
• 卷：46
• 期：5
• 页码：1754-1764
• 全文大小：650K
• 年卷期：v.46,no.5(March 12, 2013)
• ISSN：1520-5835

文摘

An efficient functionalization of aromatic main-chain polymers was established using a combination of iridium-catalyzed borylation of aromatic C鈥揌 bonds and the Suzuki鈥揗iyaura coupling reaction. Comparative studies of various iridium catalysts and borylation reagents show that [Ir(OMe)(COD)]₂ is significantly more active than [IrCl(COD)]₂, and bis(pinacolato)diboron induces higher efficiency than pinacolborane. The regioselectivity of the borylation was investigated using model compounds that mimic the repeating unit structure of poly(arylene ether sulfone). The C鈥揌 bonds of the sulfone model compound were more reactive than those of the bisphenol model compound, and the borylation occurred preferentially at the meta position to the sulfone moiety owing to steric hindrance and electronic effects. The glass transition temperature of the borylated polymer increases with increasing concentration of pinacolboronic ester group. The pinacolboronic ester group could be conveniently converted to boronic acid [B(OH)₂] and potassium trifluoroborate (BF₃K), which could also serve as versatile reactive sites for the synthesis of a wide range of functionalized polymers via Suzuki鈥揗iyaura couplings.