Rhodium-Catalyzed Enantioselective Addition of Organoaluminum Reagents to <i>N</i>-Tosyl Ketimines

Hirner, Sebastian; Kolb, Andreas; Westmeier, Johannes; Gebhardt, Sandra; Middel, Stephen; Harms, Klaus; Zezschwitz, Paultheo von

doi:10.1021/ol501372u

Cited by 36 publications

(15 citation statements)

References 54 publications

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“…351 In the conversions of ketimine 416, it was observed that the facial selectivity was the same for the addition of both methyl and phenyl groups, which is an indication of similar catalytic cycles. Nevertheless, the facial selectivities of the 1,4-addition are inverted, while the selectivity of the latter is related to that of a standard proposed by Hayashi-Miyaura for the reaction with arylboronic acids and Binap as a chiral ligand.…”

Section: Organoaluminiumsmentioning

confidence: 90%

“…This reaction route could apply to Rh-catalyzed 1,4-additions of a wide range of organometallic reagents. 350,351 Alkenylrhodium 392 can subsequently be added to a,b-enones 1 to afford oxa-p-allyl-Rh 393, followed by reaction with alkenylzirconocene chloride 389 to provide alkenylrhodium intermediate 392 and afford zirconium enolate 394 (Scheme 194). 349 In 2004, Hanzawa et al reported on a highly efficient conjugate addition reactions of alkenyl zirconocene chloride complexes 395 to a,b-enones, a,b-enoic acid esters, and a,b-enoic acid amides 396, 397, 398 catalyzed by [RhCl(cod)] 2 catalyst to provide 1,4-adducts 399, 400, 401 in excellent yields.…”

Section: Organozirconiumsmentioning

confidence: 99%

“…The observed regiodivergence in the conversion of (R)-416 might then originate from the unfavored steric interactions of the methyl group at the substrate and the binap ligand in the transitions state 420. 351 …”

Section: Organoaluminiumsmentioning

confidence: 99%

See 2 more Smart Citations

Rh-catalyzed asymmetric 1,4-addition reactions to α,β-unsaturated carbonyl and related compounds: an update

Heravi

Dehghani

Zadsirjan

2016

Tetrahedron: Asymmetry

109

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Rh-catalyzed asymmetric 1,4-addition reactions to a,b-unsaturated carbonyl and related compounds: an update Available online xxxx Dedicated to my son, OMID on the occasion of his 35th birthday. a b s t r a c tThe Rh-catalyzed asymmetric 1,4-addition of organometallic reagents to an appropriate receptor has been a growing area of research over the last decade. The receptors for such a 1,4-addition reaction are chiefly a,b-unsaturated ketones, esters, amides, enones, nitroalkenes, and occasionally phosphonates etc. This reaction in the presence of chiral rhodium complexes introduce the aryl and alkenyl groups at the b-position of the above electron poor olefins, enantioselectively. Chiral Rh complexes similar to other transition metals can be added to some electron poor olefins, in turn making them viable to attack by various organometallic reagents for highly enantioselective C-C bond formation. The Rh-catalyzed asymmetric 1,4-addition of organometallic reagents to electron poor olefins has been reviewed in 2003. Due to the importance of the asymmetric C-C bond formation via 1,4-conjugate addition reactions and the number of such reactions catalyzed by Rh-complexes, in this review we highlight the recent advances in Rh-complex asymmetric catalyzed 1,4-addition reactions since 2003.

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Section: Organoaluminiumsmentioning

confidence: 90%

Section: Organozirconiumsmentioning

confidence: 99%

See 1 more Smart Citation

Rh-catalyzed asymmetric 1,4-addition reactions to α,β-unsaturated carbonyl and related compounds: an update

Heravi

Dehghani

Zadsirjan

2016

Tetrahedron: Asymmetry

109

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“…The main advances in this area have been achieved in the field of Rh- and Pd-catalysed addition of Csp 2 -nucleophiles to N -sulfonyl ketimines using boron reagents567. However, the addition of Csp 3 -nucleophiles is restricted to methylations and ethylations of a small set of ketimines using organozinc or organoaluminium reagents with Cu, Zr or Rh catalysts8910.…”

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confidence: 99%

Catalytic enantioselective addition of Grignard reagents to aromatic silyl ketimines

et al. 2016

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α-Chiral amines are of significant importance in medicinal chemistry, asymmetric synthesis and material science, but methods for their efficient synthesis are scarce. In particular, the synthesis of α-chiral amines with the challenging tetrasubstituted carbon stereocentre is a long-standing problem and catalytic asymmetric additions of organometallic reagents to ketimines that would give direct access to these molecules are underdeveloped. Here we report a highly enantioselective catalytic synthesis of N-sulfonyl protected α-chiral silyl amines via the addition of inexpensive, easy to handle and readily available Grignard reagents to silyl ketimines. The key to this success was our ability to suppress any unselective background addition reactions and side reduction pathway, through the identification of an inexpensive, chiral Cu-complex as the catalytically active structure.

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“…von Zezschwitz et al utilized α,β-unsaturated C=N exocyclic ketimines 73 in catalytic asymmetric methylation and phenylation with organoaluminum reagents 74 (Scheme 16). 46 The reaction generally proceeded with a Rh/ BINAP complex in a 1,2-fashion in diethyl ether, whereas the reaction in toluene predominantly afforded the 1,4-adduct.…”

mentioning

confidence: 99%

Recent Advances in Catalytic Asymmetric C–C Bond-Forming Reactions to Ketimines Promoted by Metal-Based Catalysts

Kumagai

Shibasaki

2014

Bulletin of the Chemical Society of Japan

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Recent progress (post-2010) in the field of metal-catalyzed asymmetric CC bond-forming reactions using ketimines as electrophiles is reviewed. Compared with the corresponding aldimines, ketimines generally display less inherent reactivity and the two substituents on the imine carbon hamper prochiral-face-selection for enantioselective reactions. Recent advances with newly developed catalytic systems have resulted in several solutions to these long-standing problems. The construction of tetrasubstituted stereogenic centers is a crucial topic of asymmetric catalysis in the 21st century, and it is becoming increasingly clear that reactions using ketimines as electrophiles become one of the most important routes to access such chemical entities.

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Rhodium-Catalyzed Enantioselective Addition of Organoaluminum Reagents to N-Tosyl Ketimines

Cited by 36 publications

References 54 publications

Rh-catalyzed asymmetric 1,4-addition reactions to α,β-unsaturated carbonyl and related compounds: an update

Rh-catalyzed asymmetric 1,4-addition reactions to α,β-unsaturated carbonyl and related compounds: an update

Catalytic enantioselective addition of Grignard reagents to aromatic silyl ketimines

Recent Advances in Catalytic Asymmetric C–C Bond-Forming Reactions to Ketimines Promoted by Metal-Based Catalysts

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