Supported Chiral Mo-Based Complexes as Efficient Catalysts for Enantioselective Olefin Metathesis

Dolman, Sarah J.; Hultzsch, Kai C.; Pezet, Frédéric; Teng, Xin; Hoveyda, Amir H.; Schrock, Richard R.

doi:10.1021/ja047663r

Cited by 81 publications

(45 citation statements)

References 18 publications

(35 reference statements)

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“…[79] As was described for ruthenium-catalyzed metathesis, phenylamine-containing dienes are generally efficiently converted to the expected RCM products in the presence of molybdenum complexes such as 1 or 121. [80][81][82] However, in this case, there is no notable variation in reaction rate between electron-deficient arylamines and their corresponding electron-rich derivatives (Scheme 47). [80,81] These results indicate that coordination of the amino group to metal-alkylidene complexes is much less operative in theses instances than for ruthenium-catalyzed metathesis reactions of the analogous substrates (Scheme 38).…”

Section: Ruthenium-catalyzed Metathesis Of Phenylamines and Analoguesmentioning

confidence: 85%

Olefin Metathesis of Amine‐Containing Systems: Beyond the Current Consensus

Compain¹

2007

Adv Synth Catal

162

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Olefin metathesis is one of the most powerful synthetic tool to access amine-containing heterocycles and alkaloids. A major drawback associated with the use of amines concerns their ability to coordinate to metal-alkylidene complexes and to interfere unproductively with catalytic activity. Based on literature precedents, it has been established as a "dogma" that efficient metathesis reactions are suppressed in the presence of basic amines and that such substrates must invariably be deactivated by conversion of the amines to the corresponding carbamates or ammonium salts. However, an increasing number of examples of amine-containing compounds that are good substrates for metathesis is being reported in the literature. How can this "non-classical" reactivity be rationalized and exploited? The purpose of this review is to provide an overview of successful metathesis reactions performed with aminecontaining compounds in order to allow some guidelines to be formulated. A special emphasis is placed on the different parameters that may influence the outcome of the reaction such as steric effects, amine basicity, and the nature of the catalyst.

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Section: Ruthenium-catalyzed Metathesis Of Phenylamines and Analoguesmentioning

confidence: 85%

Olefin Metathesis of Amine‐Containing Systems: Beyond the Current Consensus

Compain¹

2007

Adv Synth Catal

162

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“…For instance, using norbornenyl-substituted bisphenol allows the polymer synthesis to be carried out at the last step (Scheme 5), either prior to attaching Mo (4), [22] or as Mo is already attached to the phenoxide (5). [21] In the former case, good activities and enantioselectivities are obtained (still lower than their homogeneous equivalent), and lower Mo contamination is obtained. In the latter case, it was necessary to carry out the polymerization in the presence of co-monomers in order to obtain a catalyst with good performances (problem of diffusion of the reactants in a highly cross-linked polymer).…”

Section: Immobilization Through the Alkoxide Ligandmentioning

confidence: 97%

“…Noteworthy, using this approach, by changing the imido group (2b, c) or the chiral bisphenoxides (3a, b), it is possible to improve activities and selectivities, but they never reach those obtained for the corresponding homogeneous catalysts. [21] Improving the synthesis and the performance of such types of catalysts has been sought by carrying out most synthetic steps prior to polymer formation. For instance, using norbornenyl-substituted bisphenol allows the polymer synthesis to be carried out at the last step (Scheme 5), either prior to attaching Mo (4), [22] or as Mo is already attached to the phenoxide (5).…”

Section: Immobilization Through the Alkoxide Ligandmentioning

confidence: 99%

Strategies to Immobilize Well‐Defined Olefin Metathesis Catalysts: Supported Homogeneous Catalysis vs. Surface Organometallic Chemistry

Copéret,

Basset

2007

Adv Synth Catal

210

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This review is mainly devoted to a description of the strategies that have been implemented to develop well-defined olefin metathesis catalysts immobilized on solid supports. Two main approaches have been investigated involving supported homogenous catalysts or heterogeneous catalysts prepared by surface organometallic chemistry. Advantages, limitations and possible developments of these systems are discussed.

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“…[23] Additional chiral Schrock catalysts immobilized via biphenoxides and binaphthoxides were a short time later jointly reported by the Schrock and Hoveyda groups. [24] All supported catalysts prepared so far showed excellent results in terms of activity and enantioselectivity.…”

Section: And Consisted Of a Ps-dvb-bound Version Of Moa C H T U N G Tmentioning

confidence: 93%

Polymer‐Supported Chiral Schrock Catalysts Immobilized via the Arylimido Ligand

et al. 2006

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The immobilization of both chiral and non-chiral versions of the Schrock catalyst via the arylimido ligand was accomplished for the first time. For this purpose, four different 4-(6-halogenohexyl)-2,6-R 2 -anilines, i.e., {4-[6-X-(CH 2 ) 6 ]-2,6-R 2 -C 6 H 2 -NH 2 } (7: R= Me, X = Br; 8: R= Me, X = Cl, 9: R= 2-Pr, X = Cl, 10: R= 2-Pr, X = Br) were prepared and used for the synthesis of the corresponding MobisA C H T U N G T R E N N U N G (imido)dichloro complexes Mo{N-2,6-R 2 -4-[6-X-(CH 2 ) 6 ]-C 6 H 2 } 2 Cl 2 ·DME (11: R= Me, X = Br; 12: R = Me, X = Cl; 13: R= 2-Pr, X = Cl; 14: R= 2-Pr, X = Br). Compounds 11-14 were transformed into the corresponding Mo-bisA C H T U N G T R E N N U N G (imido)dialkyl complexes Mo{N-2,6-R 2 -4-[6-X-(CH 2 ) 6 ]-C 6 H 2 } 2 (CH 2 CMe 2 Ph) 2 (15: R= Me, X = Br; 16: R= Me, X = Cl, 17: R= 2-Pr, X = Cl; 18: R= 2-Pr, X = Br). These were used for the synthesis of the Mo-imidoalkylidene triflates·DME (19: R= Me, X = Br; 20: R= 2-Pr, X = Br, 21: R= 2-Pr, X = Cl). Compounds 19--21 were used in the synthesis of the Schrock type catalysts H T U N G T R E N N U N G (CHCMe 2 Ph)[OC-A C H T U N G T R E N N U N G (CH 3 )A C H T U N G T R E N N U N G (CF 3 ) 2 ] (23), Mo{N-2,6-Me 2 -4-[6-Br-(CH 2 ) 6 ]-C 6 H 2 }A C H T U N G T R E N N U N G (CHCMe 2 Ph)[(R)-BIPHEN] (24) and MoA C H T U N G T R E N N U N G {N-2,6-A C H T U N G T R E N N U N G (2-Pr) 2 -4-[6-Br-(CH 2 ) 6 ]-C 6 H 2 }A C H T U N G T R E N N U N G (CHCMe 2 Ph)[(R)-BIPHEN] (25). Compounds 22, 24and 25 were immobilized on Ag-perfluoroalkylsulfonate-modified PS-and PS-DVB materials to yield the corresponding immobilized catalysts Mo{N-2,6-Me 2 -4-28). These were used in a series of ring-closing metathesis (RCM), ringopening cross metathesis, asymmetric RCM and desymmetrization reactions. The use of 27 and 28 resulted in values for enantiomeric excess (ee) virtually identical to those obtained with the corresponding homogeneous chiral catalysts.

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Supported Chiral Mo-Based Complexes as Efficient Catalysts for Enantioselective Olefin Metathesis

Cited by 81 publications

References 18 publications

Olefin Metathesis of Amine‐Containing Systems: Beyond the Current Consensus

Olefin Metathesis of Amine‐Containing Systems: Beyond the Current Consensus

Strategies to Immobilize Well‐Defined Olefin Metathesis Catalysts: Supported Homogeneous Catalysis vs. Surface Organometallic Chemistry

Polymer‐Supported Chiral Schrock Catalysts Immobilized via the Arylimido Ligand

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