The Experts below are selected from a list of 132 Experts worldwide ranked by ideXlab platform
Atsushi Nishida - One of the best experts on this subject based on the ideXlab platform.
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abnormal ito Saegusa Oxidation of tips enol ether assisted by a hydroxy group on a side chain
ChemInform, 2011Co-Authors: Shiharu Hiraoka, Shinji Harada, Atsushi NishidaAbstract:Although Ito-Saegusa Oxidation gives defined α,β-unsaturated ketones from silyl enol ether of ketones, controlled by the position of the sp2 carbon of the silyl enol ether, the formation of a regioisomeric product that is oxidized abnormally is observed.
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Abnormal Ito—Saegusa Oxidation of TIPS Enol Ether Assisted by a Hydroxy Group on a Side Chain.
ChemInform, 2011Co-Authors: Shiharu Hiraoka, Shinji Harada, Atsushi NishidaAbstract:Although Ito-Saegusa Oxidation gives defined α,β-unsaturated ketones from silyl enol ether of ketones, controlled by the position of the sp2 carbon of the silyl enol ether, the formation of a regioisomeric product that is oxidized abnormally is observed.
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abnormal ito Saegusa Oxidation of tips enol ether assisted by a hydroxy group on a side chain
Tetrahedron Letters, 2011Co-Authors: Shiharu Hiraoka, Shinji Harada, Atsushi NishidaAbstract:Abstract Although Ito–Saegusa Oxidation gives defined α,β-unsaturated ketones from silyl enol ether of ketones controlled by the position of the sp 2 carbon of the silyl enol ether, the formation of a regioisomeric product that was oxidized abnormally was observed. The structural requirements for the substrates, the conditions, and a plausible mechanism are presented.
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Abnormal Ito–Saegusa Oxidation of TIPS enol ether assisted by a hydroxy group on a side chain
Tetrahedron Letters, 2011Co-Authors: Shiharu Hiraoka, Shinji Harada, Atsushi NishidaAbstract:Abstract Although Ito–Saegusa Oxidation gives defined α,β-unsaturated ketones from silyl enol ether of ketones controlled by the position of the sp 2 carbon of the silyl enol ether, the formation of a regioisomeric product that was oxidized abnormally was observed. The structural requirements for the substrates, the conditions, and a plausible mechanism are presented.
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Catalytic enantioselective total synthesis of (-)-platyphyllide and its structural revision.
The Journal of organic chemistry, 2010Co-Authors: Shiharu Hiraoka, Shinji Harada, Atsushi NishidaAbstract:The catalytic asymmetric total synthesis of platyphyllide has been accomplished. A key highly substituted cyclohexene derivative has been obtained by the catalytic asymmetric Diels−Alder reaction of Danishefsky diene with an electron-deficient alkene. The Diels−Alder adduct was converted to a protected cyclohexane-1,3-dione in chiral form by catalytic Ito−Saegusa Oxidation. Although the reported structure of platyphyllide was successfully synthesized, the optical rotation was opposite that of the natural compound. The absolute configuration of natural (−)-platyphyllide is revised to be a (6S,7S)-enantiomer.
Wei Wang - One of the best experts on this subject based on the ideXlab platform.
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direct Oxidation of beta aryl substituted aldehydes to alpha beta unsaturated aldehydes promoted by an o anisidine pd oac 2 co catalyst
Chemistry-an Asian Journal, 2009Co-Authors: Hualiang Jiang, Wei Wang, Jian LiAbstract:An o-anisidine-Pd(OAc)2 catalytic system for the direct co-catalytic Saegusa Oxidation of β-aryl substituted aldehydes to α,β-unsaturated aldehydes has been developed. The use of o-anisidine in place of (S)-diphenylprolinol made the process more simply and cost-effective. The process not only features the use of unmodified aldehydes rather than enol silyl ethers, but also gives moderate to good yields (44–72 %).
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a direct amine palladium acetate cocatalyzed Saegusa Oxidation reaction of unmodified aldehydes to α β unsaturated aldehydes
Advanced Synthesis & Catalysis, 2009Co-Authors: Jin Zhu, Jie Liu, Hexin Xie, Hualiang Jiang, Wei WangAbstract:A direct preparation of synthetically useful α,β-unsaturated aldehydes from readily available aldehydes has been developed. The process is effectively cocatalyzed by an amine-palladium acetate to give rise to α,β-unsaturated aldehydes in moderate to good yields (41―62%). The reaction features the use of unmodified aldehydes rather than enol silyl ethers, which are used in a typical Saegusa Oxidation reaction.
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A Direct Amine‐Palladium Acetate Cocatalyzed Saegusa Oxidation Reaction of Unmodified Aldehydes to α,β‐Unsaturated Aldehydes
Advanced Synthesis & Catalysis, 2009Co-Authors: Jin Zhu, Jie Liu, Hexin Xie, Hualiang Jiang, Wei WangAbstract:A direct preparation of synthetically useful α,β-unsaturated aldehydes from readily available aldehydes has been developed. The process is effectively cocatalyzed by an amine-palladium acetate to give rise to α,β-unsaturated aldehydes in moderate to good yields (41―62%). The reaction features the use of unmodified aldehydes rather than enol silyl ethers, which are used in a typical Saegusa Oxidation reaction.
Dae Young Kim - One of the best experts on this subject based on the ideXlab platform.
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asymmetric synthesis of tetrahydroquinolines via Saegusa type oxidative enamine catalysis 1 5 hydride transfer cyclization sequences
Asian Journal of Organic Chemistry, 2014Co-Authors: Chang Won Suh, Saet Byeol Woo, Dae Young KimAbstract:Enantioselective organocatalytic synthesis of tetrahydroquinolines has been achieved via Saegusa-type oxidative enamine catalysis/1,5-hydride transfer/cyclization sequences. The feature of this research is a one-pot transformation of 3-aryl aldehydes into tetrahydroquinolines by using environmentally benign catalytic Saegusa Oxidation and highly efficient internal redox reactions. The synthetically useful ring-fused tetrahydroquinoline derivatives were obtained in moderate yields and high levels of enantioselectivity.
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Asymmetric Synthesis of Tetrahydroquinolines via Saegusa‐type Oxidative Enamine Catalysis/1,5‐Hydride Transfer/Cyclization Sequences
Asian Journal of Organic Chemistry, 2014Co-Authors: Chang Won Suh, Saet Byeol Woo, Dae Young KimAbstract:Enantioselective organocatalytic synthesis of tetrahydroquinolines has been achieved via Saegusa-type oxidative enamine catalysis/1,5-hydride transfer/cyclization sequences. The feature of this research is a one-pot transformation of 3-aryl aldehydes into tetrahydroquinolines by using environmentally benign catalytic Saegusa Oxidation and highly efficient internal redox reactions. The synthetically useful ring-fused tetrahydroquinoline derivatives were obtained in moderate yields and high levels of enantioselectivity.
Shiharu Hiraoka - One of the best experts on this subject based on the ideXlab platform.
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abnormal ito Saegusa Oxidation of tips enol ether assisted by a hydroxy group on a side chain
ChemInform, 2011Co-Authors: Shiharu Hiraoka, Shinji Harada, Atsushi NishidaAbstract:Although Ito-Saegusa Oxidation gives defined α,β-unsaturated ketones from silyl enol ether of ketones, controlled by the position of the sp2 carbon of the silyl enol ether, the formation of a regioisomeric product that is oxidized abnormally is observed.
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Abnormal Ito—Saegusa Oxidation of TIPS Enol Ether Assisted by a Hydroxy Group on a Side Chain.
ChemInform, 2011Co-Authors: Shiharu Hiraoka, Shinji Harada, Atsushi NishidaAbstract:Although Ito-Saegusa Oxidation gives defined α,β-unsaturated ketones from silyl enol ether of ketones, controlled by the position of the sp2 carbon of the silyl enol ether, the formation of a regioisomeric product that is oxidized abnormally is observed.
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abnormal ito Saegusa Oxidation of tips enol ether assisted by a hydroxy group on a side chain
Tetrahedron Letters, 2011Co-Authors: Shiharu Hiraoka, Shinji Harada, Atsushi NishidaAbstract:Abstract Although Ito–Saegusa Oxidation gives defined α,β-unsaturated ketones from silyl enol ether of ketones controlled by the position of the sp 2 carbon of the silyl enol ether, the formation of a regioisomeric product that was oxidized abnormally was observed. The structural requirements for the substrates, the conditions, and a plausible mechanism are presented.
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Abnormal Ito–Saegusa Oxidation of TIPS enol ether assisted by a hydroxy group on a side chain
Tetrahedron Letters, 2011Co-Authors: Shiharu Hiraoka, Shinji Harada, Atsushi NishidaAbstract:Abstract Although Ito–Saegusa Oxidation gives defined α,β-unsaturated ketones from silyl enol ether of ketones controlled by the position of the sp 2 carbon of the silyl enol ether, the formation of a regioisomeric product that was oxidized abnormally was observed. The structural requirements for the substrates, the conditions, and a plausible mechanism are presented.
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Catalytic enantioselective total synthesis of (-)-platyphyllide and its structural revision.
The Journal of organic chemistry, 2010Co-Authors: Shiharu Hiraoka, Shinji Harada, Atsushi NishidaAbstract:The catalytic asymmetric total synthesis of platyphyllide has been accomplished. A key highly substituted cyclohexene derivative has been obtained by the catalytic asymmetric Diels−Alder reaction of Danishefsky diene with an electron-deficient alkene. The Diels−Alder adduct was converted to a protected cyclohexane-1,3-dione in chiral form by catalytic Ito−Saegusa Oxidation. Although the reported structure of platyphyllide was successfully synthesized, the optical rotation was opposite that of the natural compound. The absolute configuration of natural (−)-platyphyllide is revised to be a (6S,7S)-enantiomer.
John C. S. Gray - One of the best experts on this subject based on the ideXlab platform.
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the fit for purpose development of s1p1 receptor agonist gsk2263167 using a robinson annulation and Saegusa Oxidation to access an advanced phenol intermediate
Organic Process Research & Development, 2013Co-Authors: Robert M. Harris, Benjamin I. Andrews, Stacy Clark, Jason W. B. Cooke, John C. S. GrayAbstract:A fit for purpose approach has been adopted in order to develop a robust, scalable route to the S1P1 receptor agonist, GSK2263167. The key steps include a Robinson ring annulation followed by a Saegusa Oxidation, providing rapid access to an advanced phenol intermediate. Despite the use of stoichiometric palladium acetate for the Saegusa Oxidation, near complete recovery of the palladium has been demonstrated. The remaining steps have been optimised including the removal of all chromatography. An alternative to the Saegusa Oxidation is described as well as the development of a flow process to facilitate further scale-up of the amidoxime preparation using hydroxylamine at elevated temperature.
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The Fit For Purpose Development of S1P1 Receptor Agonist GSK2263167 Using a Robinson Annulation and Saegusa Oxidation to Access an Advanced Phenol Intermediate
2013Co-Authors: Robert M. Harris, Benjamin I. Andrews, Stacy Clark, Jason W. B. Cooke, John C. S. GrayAbstract:A fit for purpose approach has been adopted in order to develop a robust, scalable route to the S1P1 receptor agonist, GSK2263167. The key steps include a Robinson ring annulation followed by a Saegusa Oxidation, providing rapid access to an advanced phenol intermediate. Despite the use of stoichiometric palladium acetate for the Saegusa Oxidation, near complete recovery of the palladium has been demonstrated. The remaining steps have been optimised including the removal of all chromatography. An alternative to the Saegusa Oxidation is described as well as the development of a flow process to facilitate further scale-up of the amidoxime preparation using hydroxylamine at elevated temperature
