- Highly Efficient Enantioselective Synthesis of Chiral Sulfones by Rh-Catalyzed Asymmetric Hydrogenation
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A highly efficient and enantioselective Rh-(R,R)-f-spiroPhos complex catalyzed hydrogenation of a series of unsaturated sulfones has been developed. With Rh-(R,R)-f-spiroPhos catalyst under mild conditions, not only the asymmetric hydrogenation of both the 3,3-diaryl and exocyclic α,β-unsaturated sulfones was first realized with up to 99.9% ee but also 3-alkyl-3-aryl and benzo[b]thiophene-1,1-dioxides were successfully hydrogenated to the corresponding chiral sulfones with excellent enantioselectivities (up to 99.4% ee) regardless of the steric hindrance, electronic property, and geometry of the substrates. Moreover, this reaction offers a route to (S)-(+)-ar-turmerone as a spice flavor, which is an important synthetic intermediate of pharmaceuticals.
- Yan, Qiaozhi,Xiao, Guiying,Wang, Ying,Zi, Guofu,Zhang, Zhanbin,Hou, Guohua
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supporting information
p. 1749 - 1756
(2019/01/25)
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- Iridium-Catalyzed Asymmetric Hydrogenation of Benzo[b]thiophene 1,1-Dioxides
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An efficient iridium-catalyzed asymmetric hydrogenation of substituted benzothiophene 1,1-dioxides is described. The use of iridium complexes with chiral pyridyl phosphinite ligands provides access to highly enantiomerically enriched sulfones with substituents at the 2- and 3-position. Sulfones of this type are of interest as core structures of agrochemicals and pharmaceuticals. Moreover, they can be further reduced to chiral 2,3-dihydrobenzothiophenes.
- Tosatti, Paolo,Pfaltz, Andreas
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supporting information
p. 4579 - 4582
(2017/04/11)
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- Cyclopenta[b]annulation of Heteroarenes by Organocatalytic γ′[C(sp3)?H] Functionalization of Ynones
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A new approach for the cyclopenta[b]annulation of heteroarenes through metal-free and directing-group-free γ′[C(sp3)?H] functionalization and intramolecular hydroalkylation of ynones has been developed. In an unprecedented event, nucleophilic addition of an organophosphine to the designed ynones triggers γ′[C(sp3)?H] functionalization, leading to the formation of heteroaryl-based ortho-quinodimethane (oQDM) intermediates that undergo carbocyclization to provide cyclopentannulated heteroarenes in good yields and excellent stereoselectivities. Deuterium-labeling experiments substantiated the proposed reaction mechanism as well as the speculated epimerization.
- Raghu, Moluguri,Grover, Jagdeep,Ramasastry
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supporting information
p. 18316 - 18321
(2016/12/16)
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- The Selective Cross-Coupling of Secondary Alkyl Zinc Reagents to Five-Membered-Ring Heterocycles Using Pd-PEPPSI-IHeptCl
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The ability to cross-couple secondary alkyl centers is fraught with a number of problems, including difficult reductive elimination, which often leads to β-hydride elimination. Whereas catalysts have been reported that provide decent selectivity for the expected (non-rearranged) cross-coupled product with aryl or heteroaryl oxidative-addition partners, none have shown reliable selectivity with five-membered-ring heterocycles. In this report, a new, rationally designed catalyst, Pd-PEPPSI-IHeptCl, is demonstrated to be effective in selective cross-coupling reactions with secondary alkyl reagents across an impressive variety of furans, thiophenes, and benzo-fused derivatives (e.g., indoles, benzofurans), in most instances producing clean products with minimal, if any, migratory insertion for the first time. A wide variety of five-membered-ring heterocycles were successfully cross-coupled to secondary alkyl zinc reagents with the new precatalyst Pd-PEPPSI-IHeptCl, which features a bulky N-heterocyclic carbene ligand. This catalyst suppresses migratory-insertion (rearrangement) pathways, and the desired products are thus formed with high selectivity.
- Atwater, Bruce,Chandrasoma, Nalin,Mitchell, David,Rodriguez, Michael J.,Pompeo, Matthew,Froese, Robert D. J.,Organ, Michael G.
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supporting information
p. 9502 - 9506
(2015/08/11)
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- Biphenylsulfonamides and derivatives thereof that modulate the activity of endothelin
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Biphenylsulfonamides and methods for modulating or altering the activity of the endothelin family of peptides are provided. In particular, bicyclic or tricyclic carbon or heterocyclic ring biphenylsulfonamides and methods using these sulfonamides for inhibiting the binding of an endothelin peptide to an endothelin receptor by contacting the receptor with the sulfonamide are provided. Methods for treating endothelin-mediated disorders by administering effective amounts of one or more of these sulfonamides or prodrugs thereof that inhibit or increase the activity of endothelin are also provided.
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- N-aryl thienyl-, furyl-, and pyrrolyl-sulfonamides and derivatives thereof that modulate the activity of endothelin
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Thienyl-, furyl- and pyrrolyl-sulfonamides and methods for modulating or altering the activity of the endothelin family of peptides are provided. In particular, N-(isoxazolyl)thienylsulfonamides, N-(isoxazolyl)furylsulfonamides and N-(isoxazolyl)pyrrolylsulfonamides and methods using these sulfonamides for inhibiting the binding of an endothelin peptide to an endothelin receptor by contacting the receptor with the sulfonamide are provided. Methods for treating endothelin-mediated disorders by administering effective amounts of one or more of these sulfonamides or prodrugs thereof that inhibit or increase the activity of endothelin are also provided.
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Page column 67
(2010/01/30)
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- THIENYL-, FURYL- AND PYRROLYL SULFONAMIDES AND DERIVATIVES THEREOF THAT MODULATE THE ACTIVITY OF ENDOTHELIN
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Thienyl-, furyl-and pyrrolyl-sulfonamides and methods for modulating or altering the activity of the endothelin family of peptides are provided. In particular, N-(isoxazolyl)thienylsulfonamides, N-(isoxazolyl) furylsulfonamides and N-(isoxazolyl)pyrrolylsulfonamides and methods using these sulfonamides for inhibiting the binding of an endothelin peptide to an endothelin receptor by contacting the receptor with the sulfonamide are provided. Methods for treating endothelin-mediated disorders by administering effective amounts of one or more of these sulfonamides or prodrugs thereof that inhibit or increase the activity of endothelin are also provided.
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