LIVING RING-OPENING METATHESIS POLYMERIZATION OF 2,3-DIFUNCTIONALIZED 7-OXANORBORNENES AND 7-OXANORBORNADIENES BY MO(CHCME2R)(N-2,6-C6H3-ISO-PR2)(O-TERT-BU)2 AND MO(CHCME2R)(N-2,6-C6H3-ISO-PR2)(OCME2CF3)2
LIVING RING-OPENING METATHESIS POLYMERIZATION OF 2,3-DIFUNCTIONALIZED 7-OXANORBORNENES AND 7-OXANORBORNADIENES BY MO(CHCME2R)(N-2,6-C6H3-ISO-PR2)(O-TERT-BU)2 AND MO(CHCME2R)(N-2,6-C6H3-ISO-PR2)(OCME2CF3)2
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DOI：
10.1021/ja00018a028
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发表时间：
1991-08-28
影响因子：
15
通讯作者：
SCHROCK, RR
中科院分区：
文献类型：
--
作者：
BAZAN, GC;OSKAM, JH;SCHROCK, RR
7-氧杂苯并降冰片二烯（9）、2，3-内-顺-二乙酰氧基-7-氧杂降冰片烯和2，3-内-顺-（异亚丙基二氧基）-7-氧杂降冰片烯可通过Mo（CHCMe 2 R）（NAr）（O-t-Bu）2（Ar = 2，6-C6 H3-i-Pr 2; R = CH 3，C6 H5）（[Mo]-（CHCMe 2 R））聚合得到具有窄分子量分布（PDI < 1.17）的聚合物。 然而，2，3-双（三氟甲基）-7-氧杂降冰片二烯（1）、2，3-二甲氧基-7-氧杂降冰片二烯（4）和2，3-反式-二氰基-7-氧杂降冰片-5-烯（12）在加入[Mo]（CHCMe 2 R）后形成稳定的金属杂环。 1与[Mo]（CHCMe 2 R）的反应速率已被定性确定为可与竞争实验中的异戊烯的反应速率相媲美，这一结果意味着7位氧上的孤对电子加速了金属配体的形成。 由1加成到[Mo]（CHCMe 2 Ph）得到的金属配体是四棱锥，其中亚氨基配体在顶端位置。 （2b的晶体数据：a = 12.420（3）埃，B = 15.466（4）埃，c = 20.856（6）埃，V = 3852（2）埃3，β = 105.97（2）度，空间群= P2（1）/n，Z = 4，M（r）= 779.76，rho = 1.345 g/cm 3，mu = 3.9 cm-1，R1 = 0.049，R2 = 0.068。） MoC 3环是平面的，CMe 2 Ph基团指向亚氨基配体，单体的C-7框架指向远离它的方向（反式金属环）。 氧在7-位上的氧位于离金属3.332（4）埃处。 电子和空间因素的影响，一阶分裂的金属乳酸盐已被研究的单体1和4。 反应性更强的催化剂Mo（CHCMe 2 Ph）（NAr）（OCMe 2CF 3）2可以取代1、4和12，得到具有窄分子量分布（PDI < 1.15）的聚合物。
7-Oxabenzonorbornadiene (9), 2,3-endo-cis-diacetoxy-7-oxanorbornene, and 2,3-endo-cis-(isopropylidenedioxy)-7-oxanorbornene can be polymerized by Mo(CHCMe2R)(NAr)(O-t-Bu)2 (Ar = 2,6-C6H3-i-Pr2; R = CH3, C6H5) ([Mo]-(CHCMe2R)) to give polymers with narrow molecular weight distributions (PDI < 1.17). However, 2,3-bis(trifluoromethyl)-7-oxanorbornadiene (1), 2,3-dicarbomethoxy-7-oxanorbornadiene (4), and 2,3-trans-dicyano-7-oxanorborn-5-ene (12) form stable metallacycles upon addition to [Mo](CHCMe2R). The rate of reaction of 1 with [Mo](CHCMe2R) has been determined qualitatively to be comparable to that of norbornene in competition experiments, a result that implies that the lone pair on the oxygen in the 7-position is accelerating metallacycle formation. The metallacycle that results from addition of 1 to [Mo](CHCMe2Ph) is square pyramidal with the imido ligand in the apical position. (Crystal data for 2b: a = 12.420 (3) angstrom, b = 15.466 (4) angstrom, c = 20.856 (6) angstrom, V = 3852 (2) angstrom 3, beta = 105.97 (2)degrees, space group = P2(1)/n, Z = 4, M(r) = 779.76, rho = 1.345 g/cm3, mu = 3.9 cm-1, R1 = 0.049, R2 = 0.068.) The MoC3 ring is planar with the CMe2Ph group pointed toward the imido ligand and the C-7 frame of the monomer pointed away from it (a trans metallacyclic ring). The oxygen in the 7-position of the norbornene moiety is located 3.332 (4) angstrom from the metal. Electronic and steric factors that influence first-order breakup of the metallacycle have been studied for monomers 1 and 4. The more reactive catalyst, Mo(CHCMe2Ph)(NAr)(OCMe2CF3)2, can polymerize 1, 4, and 12 to give polymers with narrow molecular weight distributions (PDI < 1.15).