- Asymmetric Nazarov Cyclizations of Unactivated Dienones by Hydrogen-Bond-Donor/Lewis Acid Co–Catalyzed, Enantioselective Proton-Transfer
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We report an enantioselective Nazarov cyclization catalyzed by chiral hydrogen-bond-donors in concert with silyl Lewis acids. The developed transformation provides access to tri-substituted cyclopentenones in high levels of enantioselectivity (up to 95% e.e.) from a variety of simple unactivated dienones. Kinetic and mechanistic studies are consistent with a reversible 4π-electrocyclization C?C bond-forming step followed by rate- and enantio-determining proton-transfer as the mode of catalysis. (Figure presented.).
- Metternich, Jan B.,Reiterer, Martin,Jacobsen, Eric N.
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supporting information
p. 4092 - 4097
(2020/09/01)
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- Highly enantioselective hydrogenation of 2-substituted-2-alkenols catalysed by a ChenPhos-Rh complex
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Highly enantioselective hydrogenation of a variety of 2-substituted-2- alkenols has been achieved using a ChenPhos-Rh complex as catalyst, giving ≥99% ee for most substrates. Optically active antifungal agent amorolfine was first synthesised using hydrogenation as the key step. This journal is
- Wang, Quanjun,Liu, Xueying,Liu, Xian,Li, Bin,Nie, Huifang,Zhang, Shengyong,Chen, Weiping
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supporting information
p. 978 - 980
(2014/01/06)
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- Vanadium-catalyzed asymmetric epoxidation of allylic alcohols in water
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Asymmetric V-catalyzed epoxidation of allylic alcohols can be carried out in water with chiral ligands, which incorporate sulfonamide and hydroxamic acid fragments. Furthermore, the reaction, notorious for its ligand-deceleration effect, in water turned into the ligand-accelerated process. By using this aqueous protocol, a range of allylic alcohols were epoxidized with up to 94% ee.
- Malkov, Andrei V.,Czemerys, Louise,Malyshev, Denis A.
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supporting information; experimental part
p. 3350 - 3355
(2009/09/26)
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- PROMOTERS FOR THE PROLIFERATION AND DIFFERENTIATION OF STEM CELLS AND/OR NEURON PRECURSOR CELLS
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An agent for promoting the proliferation or differentiation of a stem cell and/or neural progenitor cell, comprising a compound represented by Formula: wherein each of R1 and R2 is H, a hydrocarbon group or a heterocyclic group, or taken together with the adjacent carbon atom to form a ring, R3 is H, a hydrocarbon group or a heterocyclic group, W is a group represented by Formula: wherein Ring A is an optionally substituted benzene ring, Ring B is an optionally substituted 5- to 7-membered nitrogen-containing heterocyclic ring, R4 is an acyl group having an aliphatic hydrocarbon group, which is substituted by an aromatic group and may have a further substitutent, or aromatic group, R5 is H, C1-6 alkyl or acyl, R4c is an aromatic group, an aliphatic hydrocarbon group or acyl, and X is O or S; Y is O, S or NH, Ring C is an optionally substituted benzene ring, or a salt or prodrug thereof is provided.
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- Benzofuran derivatives, their production and use
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Compounds represented by the formula: wherein R1 and R2 are hydrogen atom, a hydrocarbon group or a heterocyclic group, or R1 and R2 may form, together with the adjacent carbon atom, a 3- to 8-membered homocyclic or heterocyclic ring, W indicates (i) a group represented by the formula: wherein ring B indicates a 5- to 7-membered ring, or (ii) a group represented by the formula: wherein R4 indicates (1) an aliphatic hydrocarbon group, which may be substituted with an aromatic group, or (2) an acyl group containing an aromatic group, R5 is hydrogen atom, a C1-6 alkyl, or an acyl group, provided that, when W is Wa, R3 is hydrogen atom, a hydrocarbon group or a heterocyclic group, when W is Wb, R3 indicates a C6-14 aryl group, or salts thereof or prodrugs thereof have an excellent action to inhibit neurodegeneration and the like as well as an excellent brain penetrability and are low in the toxicity, thereby being useful as prophylactic or therapeutic drugs for nerve degenerative diseases and the like.
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- Antiinflammatory 4,5-diaryl-α-polyfluoroalkyl-1H-pyrrole-2-methanols and method for use thereof
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4,5-Diaryl-α-polyfluoroalkyl-1H-pyrrole-2-methanols, such as 4,5-bis (4-fluorophenyl)-α, α-bis (trifluoromethyl)-1H-pyrrole-2-methanol, are useful in treatment of inflammation and relieving pain.
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- Anti-inflammatory 4,5-diaryl-α-(polyfluoroalkyl)-1H-pyrrole-2-methanamines
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4,5-Diaryl-α-(polyfluoroalkyl)-1H-pyrrole-2-methanamines such as 4,5-bis(4-fluorophenyl)-αα-bis-(trifluoromethyl)-1H-pyrrole-2-methanamine, useful in treatment of inflammation.
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- Antiinflammatory 4,5-diaryl-α,α-bis(polyfluoromethyl)-1H-pyrrole-2-methanethiols
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4,5-Diaryl-α,α-bis(polyfluoromethyl)-1H-pyrrole-2-methanethiols, such as 4,5-bis(4-fluorophenyl)-α, α-bis(trifluoromethyl)-1H-pyrrole-2-methanethiol, useful in treatment of inflammation.
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