Highly efficient syntheses of acetoxy- and hydroxy-terminated telechelic poly(butadiene)s using ruthenium catalysts containing N-heterocyclic ligands
Highly efficient syntheses of acetoxy- and hydroxy-terminated telechelic poly(butadiene)s using ruthenium catalysts containing N-heterocyclic ligands
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DOI：
10.1016/s0032-3861(00)00504-8
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发表时间：
2001-05-01
期刊：
影响因子：
4.6
通讯作者：
Grubbs, RH
中科院分区：
文献类型：
--
作者：
Bielawski, CW;Scherman, OA;Grubbs, RH
以1,4-双(乙酰氧基)-2-丁烯作为链转移剂(CTA)，通过环辛二烯的开环复分解聚合(ROMP)制备了分子量可控制在3.0 X 10(4)以下的双(乙酰氧基)封端遥爪聚丁二烯(PBD)。聚合反应由高活性钌催化剂 1,3-双(2,4,6-三甲基苯基)咪唑-2-亚基)(PCp3)(Cl2Ru = CHCHC(CH3)(2) (Cp = 环戊基)(6) 催化，单体/催化剂比例高达 9.8 X 10(4)。用氢氧化钠去除乙酰氧基对遥爪 PBD 的检查揭示了一种独特的 1,4-PBD 微观结构，其主要是反式几何结构（高达 90%），6 的高活性和稳定性允许使用未受保护的游离醇 2-丁烯-1,4-二醇一步合成 HTPBD，如 CTA (C) 2001 Elsevier Science Ltd. All。保留权利。
Bis(acetoxy)-tenninated telechelic poly(butadiene) (PBD) with molecular weights controllable up to 3.0 X 10(4) have been prepared via the ring-opening metathesis polymerization (ROMP) of cyclooctadiene when 1,4-bis(acetoxy)-2-butene was included as a chain transfer agent (CTA). The polymerizations were catalyzed by a highly active ruthenium catalyst 1,3-bis(2,4,6-trimethylphenyl)imidazol-2- ylidene)(PCp3)(Cl2Ru = CHCHC(CH3)(2) (Cp = cyclopentyl) (6) with monomer/catalyst ratios as high as 9.8 X 10(4). Removal of the acetoxy groups with sodium hydroxide afforded hydroxy end-terminated telechelic PBD (HTPBD). Examination of the telechelic PBDs revealed an exclusive 1,4-PBD microstructure with a predominately trans geometry (up to 90%). The high activity and stability of 6 permitted a one-step synthesis of HTPBD using the unprotected free alcohol, 2-butene-1,4-diol, as the CTA. (C) 2001 Elsevier Science Ltd. All rights reserved.