Elser Iris, Schowner Roman, Frey Wolfgang, Buchmeiser Michael R
Institute of Polymer Chemistry, University of Stuttgart, Pfaffenwaldring 55, 70569, Stuttgart, Germany.
Institute of Organic Chemistry, University of Stuttgart, Pfaffenwaldring 55, 70569, Stuttgart, Germany.
Chemistry. 2017 May 5;23(26):6398-6405. doi: 10.1002/chem.201700213. Epub 2017 Apr 12.
Ionic Mo- and W-imido alkylidene N-heterocyclic carbene (NHC) olefin metathesis catalysts, [Mo{N-2,6-(Me )C H }(CHCMe Ph)(IMesH )(OTf)(PPS)]OTf (3), [Mo(N-2,6-(Me )C H )(CHCMe Ph)(IMesH )(OC F )(PPS)][B(Ar ) ] (5), [Mo(NtBu)(CHCMe Ph)(4,5-dichloro-1,3-dimethylimidazol-2-ylidene)(OTf)(2,6-Ph-4-{2,4,6-Ph-pyridinium}phenolate)][OTf] (9), [Mo(NtBu)(CHCMe Ph)(4,5-dichloro-1,3-dimethylimidazol-2-ylidene)(2,6-Ph-4-{2,4,6-Ph-pyridinium}phenolate)][B(Ar ) ] (10, PPS=pyridiniumpropanesulfonate, IMesH =1,3-dimesitylimidazolin-2-ylidene, OTf=CF SO , B(Ar ) =tetrakis(3,5-bis(trifluoromethyl)phenyl)borate) were prepared from betaine-type ligands. Also, the first bis-NHC and a nitron-based bis(amido) bistriflate imido alkylidene complex, [Mo(NtBu)(CHCMe Ph)(4,5-dichloro-1,3-dimethylimidazol-2-ylidene) (THF)(2,6-Ph-4-{2,4,6-Ph-pyridinium}phenolate)][OTf] (11) and [Mo(N-2,6-Me -C H )(CHCMe Ph)(N-{1,4-diphenyl-1,3,4-triazol-2-ylium}-N-phenyl-amido) ][OTf] (14) along with ionic [W(N-2,6-iPr -C H )(CHCMe Ph)(N-2,5-Me C H )(IiPr)(2,6-tBu-4-PPh -phenolate)] (17, IiPr=1,3-diisopropylimidazol-2-ylidene) are reported. With these new catalysts, the first biphasic reaction setup with Group 6 metal alkylidene NHC complexes was successfully established using a pyrrole/heptane mixture as a liquid phase. Productivities under biphasic conditions were comparable to those of reactions in 1,2-dichloroethane or toluene. Metal concentrations of <2 ppm migrated into the nonpolar heptane phase as measured by inductively coupled plasma-optical emission spectroscopy.
离子型钼和钨亚胺基亚烷基氮杂环卡宾（NHC）烯烃复分解催化剂，[Mo{N-2,6-(Me )C H }(CHCMe Ph)(IMesH )(OTf)(PPS)]OTf（3）、[Mo(N-2,6-(Me )C H )(CHCMe Ph)(IMesH )(OC F )(PPS)][B(Ar ) ]（5）、[Mo(NtBu)(CHCMe Ph)(4,5-二氯-1,3-二甲基咪唑-2-亚基)(OTf)(2,6-苯基-4-{2,4,6-苯基-吡啶鎓}酚盐)][OTf]（9）、[Mo(NtBu)(CHCMe Ph)(4,5-二氯-1,3-二甲基咪唑-2-亚基)(2,6-苯基-4-{2,4,6-苯基-吡啶鎓}酚盐)][B(Ar ) ]（10，PPS = 吡啶鎓丙烷磺酸盐，IMesH = 1,3-二甲基咪唑啉-2-亚基，OTf = CF SO ，B(Ar ) = 四(3,5-双(三氟甲基)苯基)硼酸盐）由甜菜碱型配体制备而成。此外，还报道了首例双-NHC以及基于硝酮的双(酰胺基)双三氟甲磺酰亚胺基亚烷基配合物，[Mo(NtBu)(CHCMe Ph)(4,5-二氯-1,3-二甲基咪唑-2-亚基)(THF)(2,6-苯基-4-{2,4,6-苯基-吡啶鎓}酚盐)][OTf]（11）和[Mo(N-2,6-Me -C H )(CHCMe Ph)(N-{1,4-二苯基-1,3,4-三唑-2-鎓}-N-苯基-酰胺基) ][OTf]（14）以及离子型[W(N-2,6-iPr -C H )(CHCMe Ph)(N-2,5-Me C H )(IiPr)(2,6-叔丁基-4-PPh -酚盐)]（17，IiPr = 1,3-二异丙基咪唑-2-亚基）。使用这些新型催化剂，首次成功建立了使用吡咯/庚烷混合物作为液相的第6族金属亚烷基NHC配合物的双相反应体系。双相条件下的产率与在1,2-二氯乙烷或甲苯中的反应产率相当。通过电感耦合等离子体发射光谱法测得，金属浓度<2 ppm迁移到了非极性庚烷相中。
