Dipyrrolyl precursors to bisalkoxide molybdenum olefin metathesis catalysts

被引：88

作者：

Hock, A. S.

Schrock, Richard R. ^{[1
]}

Hoveyda, Amir H.

机构：

[1] MIT, Dept Chem 6331, Cambridge, MA 02139 USA

[2] Boston Coll, Dept Chem, Merkert Chem Ctr, Chestnut Hill, MA 02467 USA

来源：

JOURNAL OF THE AMERICAN CHEMICAL SOCIETY | 2006年 / 128卷 / 50期

关键词：

D O I：

10.1021/ja0665904

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

Addition of 2 equiv of lithium pyrrolide to Mo(NR)(CHCMe2R')(OTf)(2)(DME) (OTf = OSO2CF3; R = 2,6-i-Pr2C6H3, 1-adamantyl, or 2,6-Br-2-4-MeC6H2; R' = Me or Ph) produces Mo(NR)(CHCMe2R')(NC4H4)(2) complexes in good yield. All compounds can be recrystallized readily from toluene or mixtures of pentane and ether and are sensitive to air and moisture. An X-ray structure of a 2,6-diisopropylphenylimido species shows it to be an unsymmetric dimer, {Mo(NAr)(syn-CHCMe2Ph)(eta(5)-NC4H4)(eta(1)-NC4H4)}{Mo(NAr)(syn-CHCMe2Ph)(eta(1)-NC4H4)2}, in which the nitrogen in the eta(5)-pyrrolyl bound to one Mo behaves as a donor to the other Mo. All complexes are fluxional on the NMR time scale at room temperature, with one symmetric species being observed on the NMR time scale at 50 degrees C in toluene-d(8). The dimers react with PMe3 (at Mo) or B(C6F5)(3) (at a eta(5)-NC4H4 nitrogen) to give monomeric products in high yield. They also react rapidly with 2 equiv of monoalcohols (e.g., Me3COH or (CF3)(2)MeCOH) or 1 equiv of a biphenol or binaphthol to give 2 equiv of pyrrole and bisalkoxide or diolate complexes in similar to 100% yield.

引用

页码：16373 / 16375

页数：3

共 15 条

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