A rhodium(I)-xylyl-BINAP catalyzed asymmetric ynamide-[2+2+2] cycloaddition in the synthesis of optically enriched N,O-biaryls

Oppenheimer, Jossian; Johnson, Whitney L.; Figueroa, Ruth; Hayashi, Ryuji; Hsung, Richard P.

doi:10.1016/j.tet.2009.03.078

Cited by 46 publications

(10 citation statements)

References 89 publications

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“…61 The introduction and stereochemical control of two newly formed chiral axes has been found possible by work published by Hsung and co-workers. 62 Interestingly, they utilised a chiral ynamide with a diyne in the presence of catalysts like 16/AgSbF 6 , 17 (activated with H 2 ) or even [Rh(PPh 3 ) 3 Cl]/ AgSbF 6 , but all of which being inferior to 17/(S)-xylyl-BINAP at 85 1C in 1,2-dichloroethane with additive molecular sieves. Yields up to 85% and excellent enantioselectivities of up to 99% ee for the formation of the single atropochiral biaryl bond have been recorded.…”

Section: Rhodium(i)-complexes As Catalystsmentioning

confidence: 99%

Preparation and synthetic applications of alkene complexes of group 9 transition metals in [2+2+2] cycloaddition reactions

2011

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The [2+2+2] cycloaddition reaction has become an invaluable tool for the synthetic chemistry in recent years, due to the increase of complexity of the accessed target molecules by this methodology. Over several decades, the members of group 9 of the periodic table have contributed significantly to the development and understanding of this particular cycloaddition reaction. On the other hand, catalyst complexes containing alkenes as ligands are widely used today as either catalysts or as precursor molecules for the facile generation of catalytically active metal species. In this tutorial review we want to describe the catalytically relevant chemistry of group 9 metal-alkene complexes and compile some recent applications in [2+2+2] cycloaddition reactions.

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Section: Rhodium(i)-complexes As Catalystsmentioning

confidence: 99%

Preparation and synthetic applications of alkene complexes of group 9 transition metals in [2+2+2] cycloaddition reactions

2011

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“…These products were obtained by a Rh(I)-catalyzed asymmetric [2 + 2 + 2] cycloaddition of ynamines 206 with 1,6-diynes 207 (Scheme 63). [100] Using (S)-DM-BINAP L8 as the ligand, cycloadditions of achiral 6-membered 2-oxazinone rings (n = 1) afforded products with good yields and enantioselectivities, with the diastereomer 208 b being formed preferentially (d.r. up to 8 : 1).…”

Section: Other Six-membered Heterocyclesmentioning

confidence: 99%

Asymmetric Synthesis of Axially Chiral C−N Atropisomers

Rodríguez‐Salamanca

Fernández

Hornillos

et al. 2022

Chemistry A European J

120

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Molecules with restricted rotation around a single bond or atropisomers are found in a wide number of natural products and bioactive molecules as well as in chiral ligands for asymmetric catalysis and smart materials. Although most of these compounds are biaryls and heterobiaryls displaying a CÀ C stereogenic axis, there is a growing interest in less common and more challenging axially chiral CÀ N atropisomers. This review offers an overview of the various methodologies available for their asymmetric synthesis. A brief introduction is initially given to contextualize these axially chiral skeletons, including a historical background and examples of natural products containing axially chiral CÀ N axes. The preparation of different families of CÀ N based atropisomers is then presented from anilides to chiral fiveand six-membered ring heterocycles. Special emphasis has been given to modern catalytic asymmetric strategies over the past decade for the synthesis of these chiral scaffolds. Applications of these methods to the preparation of natural products and biologically active molecules will be highlighted along the text.

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“…On the basis of Tanaka’s work, Hsung and co-workers subsequently realized a similar intermolecular [2 + 2 + 2] cycloaddition reaction of diynes 1 with achiral conjugated aryl ynamides bearing a five-membered 2-oxazolone ring or a six-membered 2-oxazinone ring (Scheme ). The substrates reacted in the presence of [Rh(cod) 2 ]BF 4 (10 mol %) and ( S )-xyl-BINAP 3 (10 mol %) in 1,2-dichloroethane at 85 °C to provide the expected chiral N , O -biaryls 6 and 8 with C–C and C–N axial chirality in high yields, moderate diastereoselectivities, and good to excellent ee values. Note that terminal alkynes worked equally well, affording the corresponding cycloadducts with single diastereoisomers due to the free C–N bond rotation.…”

Section: Cycloaddition Reactionmentioning

confidence: 99%

Exploiting Remarkable Reactivities of Ynamides: Opportunities in Designing Catalytic Enantioselective Reactions

et al. 2020

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Ynamides consisting of an electron-withdrawing group on the nitrogen atom have proven to be powerful and versatile building blocks that are involved in a variety of useful chemical transformations. Nonetheless, their utilization in asymmetric catalysis is still in its infancy and has only recently attracted the attention of the synthetic organic community. The focus of this review is to present an overview on the exciting results achieved thus far in the field of asymmetric catalytic reactions of ynamides with an emphasis on the advantages, limitations, mechanisms, and applications associated with current approaches. In addition, a personal outlook on the challenges and limitations that need to be overcome in this area is also given at the end.

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A rhodium(I)-xylyl-BINAP catalyzed asymmetric ynamide-[2+2+2] cycloaddition in the synthesis of optically enriched N,O-biaryls

Cited by 46 publications

References 89 publications

Preparation and synthetic applications of alkene complexes of group 9 transition metals in [2+2+2] cycloaddition reactions

Preparation and synthetic applications of alkene complexes of group 9 transition metals in [2+2+2] cycloaddition reactions

Asymmetric Synthesis of Axially Chiral C−N Atropisomers

Exploiting Remarkable Reactivities of Ynamides: Opportunities in Designing Catalytic Enantioselective Reactions

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