15399-05-0Relevant articles and documents
Primary Alcohols via Nickel Pentacarboxycyclopentadienyl Diamide Catalyzed Hydrosilylation of Terminal Epoxides
Lambert, Tristan H.,Steiniger, Keri A.
supporting information, p. 8013 - 8017 (2021/10/25)
The efficient and regioselective hydrosilylation of epoxides co-catalyzed by a pentacarboxycyclopentadienyl (PCCP) diamide nickel complex and Lewis acid is reported. This method allows for the reductive opening of terminal, monosubstituted epoxides to form unbranched, primary alcohols. A range of substrates including both terminal and nonterminal epoxides are shown to work, and a mechanistic rationale is provided. This work represents the first use of a PCCP derivative as a ligand for transition-metal catalysis.
Asymmetric Synthesis of N-Substituted α-Amino Esters from α-Ketoesters via Imine Reductase-Catalyzed Reductive Amination
Yao, Peiyuan,Marshall, James R.,Xu, Zefei,Lim, Jesmine,Charnock, Simon J.,Zhu, Dunming,Turner, Nicholas J.
supporting information, p. 8717 - 8721 (2021/03/16)
N-Substituted α-amino esters are widely used as chiral intermediates in a range of pharmaceuticals. Here we report the enantioselective biocatalyic synthesis of N-substituted α-amino esters through the direct reductive coupling of α-ketoesters and amines employing sequence diverse metagenomic imine reductases (IREDs). Both enantiomers of N-substituted α-amino esters were obtained with high conversion and excellent enantioselectivity under mild reaction conditions. In addition >20 different preparative scale transformations were performed highlighting the scalability of this system.
Erbium-Catalyzed Regioselective Isomerization-Cobalt-Catalyzed Transfer Hydrogenation Sequence for the Synthesis of Anti-Markovnikov Alcohols from Epoxides under Mild Conditions
Liu, Xin,Longwitz, Lars,Spiegelberg, Brian,T?njes, Jan,Beweries, Torsten,Werner, Thomas
, p. 13659 - 13667 (2020/11/30)
Herein, we report an efficient isomerization-transfer hydrogenation reaction sequence based on a cobalt pincer catalyst (1 mol %), which allows the synthesis of a series of anti-Markovnikov alcohols from terminal and internal epoxides under mild reaction conditions (≤55 °C, 8 h) at low catalyst loading. The reaction proceeds by Lewis acid (3 mol % Er(OTf)3)-catalyzed epoxide isomerization and subsequent cobalt-catalyzed transfer hydrogenation using ammonia borane as the hydrogen source. The general applicability of this methodology is highlighted by the synthesis of 43 alcohols from epoxides. A variety of terminal (23 examples) and 1,2-disubstituted internal epoxides (14 examples) bearing different functional groups are converted to the desired anti-Markovnikov alcohols in excellent selectivity and yields of up to 98%. For selected examples, it is shown that the reaction can be performed on a preparative scale up to 50 mmol. Notably, the isomerization step proceeds via the most stable carbocation. Thus, the regiochemistry is controlled by stereoelectronic effects. As a result, in some cases, rearrangement of the carbon framework is observed when tri-and tetra-substituted epoxides (6 examples) are converted. A variety of functional groups are tolerated under the reaction conditions even though aldehydes and ketones are also reduced to the respective alcohols under the reaction conditions. Mechanistic studies and control experiments were used to investigate the role of the Lewis acid in the reaction. Besides acting as the catalyst for the epoxide isomerization, the Lewis acid was found to facilitate the dehydrogenation of the hydrogen donor, which enhances the rate of the transfer hydrogenation step. These experiments additionally indicate the direct transfer of hydrogen from the amine borane in the reduction step.
SELECTIVE INHIBITORS OF NLRP3 INFLAMMASOME
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Paragraph 0466; 0485; 0492, (2019/02/15)
The present disclosure relates to compounds of Formula (I): (I); and to their pharmaceutically acceptable salts, pharmaceutical compositions, methods of use, and methods for their preparation. The compounds disclosed herein are useful for inhibiting the maturation of cytokines of the IL-1 family by inhibiting inflammasomes and may be used in the treatment of disorders in which inflammasome activity is implicated, such as autoinflammatory and autoimmune diseases and cancers.
MACROCYCLIC INHIBITORS OF HEPATITIS C PROTEASE
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Page/Page column 93, (2010/04/25)
The invention provides macrocyclic compounds inhibitory to the Hepatitis C viral protease, compositions and combinations including the compounds, methods of treatment of conditions wherein inhibition of the Hepatitis C viral protease is medically indicated, and methods of treatment of a Hepatitis C viral infection in a human patient.
Diphosphines and Metal Complexes
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Page/Page column 15, (2009/10/31)
Compounds of the formula I or I′, where the radicals R1 are each, independently of one another, a hydrogen atom or C1-C4-alkyl and R′1, is C1-C4-alkyl; X1 and X2 are each, independently of one another, a sec-phosphino group; R2 is hydrogen, R01R02R03Si— is halogen-, hydroxyl-, C1-C8-alkoxy- or R04R05N-substituted C1-C18-acyl or is R06—X01—C(O)—; R01, R02 and R03 are each, independently of one another, C1-C12-alkyl, unsubstituted or C1-C4-alkyl- or C1-C4-alkoxy-substituted C6-C10-aryl or C7-C12-aralkyl; R04 and R05 are each, independently of one another, hydrogen, C1-C12-alkyl, C3-C8-cycloalkyl, C6-C10-aryl or C7-C12-aralkyl, or R04 and R05 together are trimethylene, tetramethylene, pentamethylene or 3-oxapentylene; R06 is C1-C18-alkyl, unsubstituted or C1-C4-alkyl- or C1-C4-alkoxy-substituted C3-C8-cycloalkyl, C6-C10-aryl or C7-C12-aralkyl; X01 is —O— or —NH—; T is C-bonded C3-C20-heteroarylene; v is 0 or an integer from 1 to 4; X1 in the heteroring of the heteroarylene is bound in the ortho position relative to the T—C* bond; and * indicates a mixture of racemic or enantiomerically pure diastereomers or pure racemic or enantiomerically pure diastereomers. The compounds are excellent chiral ligands for metal complexes as enantioselective catalysts for the hydrogenation of prochiral organic compounds.
Manganese-promoted regioselective ring-opening of 2,3-epoxy acid derivatives: a new route to α-hydroxy acid derivatives
Concellon, Jose M.,Bernad, Pablo L.,Rodriguez-Solla, Humberto,Diaz, Pamela
experimental part, p. 2178 - 2184 (2009/12/31)
A simple and general methodology directed towards the synthesis 3-aryl-2-hydroxy amides, or esters with total regioselectivity from the easily available 2,3-epoxy amides or esters, promoted by active manganese is described. Utilizing enantiopure epoxy amides as starting materials, the corresponding 3-aryl-2-hydroxy amides in enantiopure form are also available. Some synthetic applications of selected examples of 3-aryl-2-hydroxy carboxylic acid derivatives are shown. A mechanism has been proposed to explain this novel reaction.
Magnetically separable Pd catalyst for highly selective epoxide hydrogenolysis under mild conditions
Kwon, Min Serk,Park, In Soo,Jang, Jum Suk,Lee, Jae Sung,Park, Jaiwook
, p. 3417 - 3419 (2008/02/12)
A magnetically separable palladium catalyst was synthesized simply through a sol-gel process incorporating palladium nanoparticles and superparamagnetic iron oxide nanoparticles in aluminum oxyhydroxide matrix, which is highly active and selective for epoxide hydrogenolysis at room temperature under 1 atm H 2. The catalyst was recycled for 25 times without loss of the activity.
Deracemisation of aryl substituted α-hydroxy esters using Candida parapsilosis ATCC 7330: Effect of substrate structure and mechanism
Baskar,Pandian,Priya,Chadha, Anju
, p. 12296 - 12306 (2007/10/03)
Candida parapsilosis ATCC 7330 was found to be an efficient biocatalyst for the deracemisation of aryl α-hydroxy esters (65-85% yield and 90-99% ee). A variety of aryl and aryl substituted α-hydroxy esters were synthesized to reflect steric and electronic effects on biocatalytic deracemisation. The mechanism of this biocatalytic deracemisation was found to be stereoinversion.
Tyrosine phosphatase inhibitors
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, (2008/06/13)
A compound of the formula (I): wherein X1 and X2 are the same or different and each is a bond or a spacer having 1 to 20 atom(s) in the main chain; one of R1 and R2 is a cycle group having substituent(s) selected from 1) an optionally substituted carboxy-C1-6 alkoxy group and 2) an optionally substituted carboxy-C1-6 aliphatic hydrocarbon group, wherein the cycle group optionally has additional substituent(s), and the other is an optionally substituted cycle group or a hydrogen atom; and R3, R4 and R5 are the same or different and each is a hydrogen atom or a substituent, or R4 may link together with R3 or R5 to form an optionally substituted ring; provided that when R3 is a hydrogen atom, R4 is a hydrogen atom and R5 is methyl, X2—R2 is not 4-cyclohexylphenyl; when R3 is 4-methoxyphenyl, R4 is a hydrogen atom and R5 is methyl, X2—R2 is not 4-methoxyphenyl; and when R1 or R2 is a hydrogen atom, the adjacent X1 or X2 is not a C1-7 alkylene; or a salt thereof exhibits a protein tyrosine phosphatase inhibitory action and is useful as a prophylactic or therapeutic agent for diabetes or the like.
