The Experts below are selected from a list of 4002 Experts worldwide ranked by ideXlab platform
Jeffrey Aube - One of the best experts on this subject based on the ideXlab platform.
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improved Schmidt conversion of aldehydes to nitriles using azidotrimethylsilane in 1 1 1 3 3 3 hexafluoro 2 propanol
Molecules, 2015Co-Authors: Hashim F. Motiwala, Qin Yin, Jeffrey AubeAbstract:The Schmidt Reaction of aromatic aldehydes using a substoichiometric amount (40 mol %) of triflic acid is described. Low catalyst loading was enabled by a strong hydrogen-bond-donating solvent hexafluoro-2-propanol (HFIP). This improved protocol tolerates a broad scope of aldehydes with diverse functional groups and the corresponding nitriles were obtained in good to high yields without the need for aqueous work up.
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Overcoming product inhibition in catalysis of the intramolecular Schmidt Reaction
Journal of the American Chemical Society, 2013Co-Authors: Hashim F. Motiwala, Charlie Fehl, Sze Wan Li, Erin Hirt, Patrick Porubsky, Jeffrey AubeAbstract:A method for carrying out the intramolecular Schmidt Reaction of alkyl azides and ketones using a substoichiometric amount of catalyst is reported. Following extensive screening, the use of the strong hydrogen-bond-donating solvent hexafluoro-2-propanol was found to be consistent with low catalyst loadings, which ranged from 2.5 mol % for favorable substrates to 25 mol % for more difficult cases. Reaction optimization, broad substrate scope, and preliminary mechanistic studies of this improved version of the Reaction are described.
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stereocontrol in a combined allylic azide rearrangement and intramolecular Schmidt Reaction
ChemInform, 2012Co-Authors: Osvaldo Gutierrez, Dean J. Tantillo, Jeffrey AubeAbstract:In the presence of a Lewis acid, an interconverting set of isomeric allylic azides undergoes the Schmidt Reaction to afford substituted lactams stereoselectively.
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Stereocontrol in a combined allylic azide rearrangement and intramolecular Schmidt Reaction
Journal of the American Chemical Society, 2012Co-Authors: Ruzhang Liu, Osvaldo Gutierrez, Dean J. Tantillo, Jeffrey AubeAbstract:Pre-equilibration of an interconverting set of isomeric allylic azides is coupled with an intramolecular Schmidt Reaction to afford substituted lactams stereoselectively. The effect of substitution and a preliminary mechanistic study are reported. The synthetic potential of this method is demonstrated in the context of an enantioselective synthesis of an advanced intermediate leading toward pinnaic acid.
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a tandem prins Schmidt Reaction approach to marine alkaloids formal and total syntheses of lepadiformines a and c
Organic Letters, 2010Co-Authors: Angelica M Meyer, Christopher E Katz, David Vander Velde, Jeffrey AubeAbstract:The tricyclic core of the cylindricine or lepadiformine families of alkaloid natural products was assembled via a Prins addition/intramolecular Schmidt rearrangement under Lewis acid conditions. Both single-pot and two-stage variations of this process were examined, with particular attention to the stereochemical outcome of the processes. This technology has been applied to a formal total synthesis of lepadiformine A and a total synthesis of lepadiformine C.
Maria Luisa Gelmi - One of the best experts on this subject based on the ideXlab platform.
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1h azepine 2 oxo 5 amino 5 carboxylic acid a 310 helix inducer and an effective tool for functionalized gold nanoparticles
Journal of Organic Chemistry, 2015Co-Authors: Sara Pellegrino, Alessandro Moretto, Francesca Clerici, Raffaella Soave, Alessandro Contini, Andrea Bonetti, Maria Luisa GelmiAbstract:A new α,α-disubstituted constrained glutamine analogue has been designed to decorate gold nanoparticles and to induce a 310-helix when inserted in peptides. Using an efficient “one-pot” asymmetric Schmidt Reaction between 4-disubstituted-cyclohexanone and hydroxyalkylazides, 1H-azepine-2-oxo-5-amino-5-carboxylic acid was prepared. The main (R) isomer was inserted at the N-terminus in a very short peptide sequence (i.e., PhCO-(R)-Oxo-Azn-l-Ala-Aib-l-AlaNHMe) and a stable 310-helix conformation was obtained, as verified by both NMR experiments and molecular dynamics (MD) simulations. Finally, the presence of the hydroxyl chain at the nitrogen atom of the ring allowed for the preparation of covered chiral gold nanoparticles.
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1H‑Azepine-2-oxo-5-amino-5-carboxylic Acid: A 310 Helix Inducer and an Effective Tool for Functionalized Gold Nanoparticles
2015Co-Authors: Sara Pellegrino, Alessandro Moretto, Francesca Clerici, Raffaella Soave, Alessandro Contini, Andrea Bonetti, Maria Luisa GelmiAbstract:A new α,α-disubstituted constrained glutamine analogue has been designed to decorate gold nanoparticles and to induce a 310-helix when inserted in peptides. Using an efficient “one-pot” asymmetric Schmidt Reaction between 4-disubstituted-cyclohexanone and hydroxyalkylazides, 1H-azepine-2-oxo-5-amino-5-carboxylic acid was prepared. The main (R) isomer was inserted at the N-terminus in a very short peptide sequence (i.e., PhCO-(R)-Oxo-Azn-l-Ala-Aib-l-AlaNHMe) and a stable 310-helix conformation was obtained, as verified by both NMR experiments and molecular dynamics (MD) simulations. Finally, the presence of the hydroxyl chain at the nitrogen atom of the ring allowed for the preparation of covered chiral gold nanoparticles
Fu-min Zhang - One of the best experts on this subject based on the ideXlab platform.
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Total Synthesis of (−)-FR901483
2012Co-Authors: Jin-bao Peng, Qing-yun Dou, Si-hua Hou, Fu-min Zhang, Shao-hua WangAbstract:A total synthesis of the immunosuppressive alkaloid (−)-FR901483 (1) has been described. The intriguingly azatricyclic structure of 1 was constructed by the semipinacol-type rearrangement and intramolecular Schmidt Reaction of an azido cyclohexanone derivative. This strategy provides a distinctive and competitive approach to the natural product 1
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development of the intramolecular prins cyclization Schmidt Reaction for the construction of the azaspiro 4 4 nonane application to the formal synthesis of stemonamine
ChemInform, 2011Co-Authors: Zhihua Chen, Shuyu Zhang, Fu-min ZhangAbstract:Treatment of the azide (I) with TiCl4 results in a new and efficient formation of the spiro compound (II).
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development of the intramolecular prins cyclization Schmidt Reaction for the construction of the azaspiro 4 4 nonane application to the formal synthesis of stemonamine
Organic Letters, 2011Co-Authors: Zhihua Chen, Shuyu Zhang, Fu-min ZhangAbstract:A TiCl(4)-promoted tandem intramolecular Prins cyclization/Schmidt Reaction has been designed and developed to be an efficient method for the construction of the azaspiro[4,4]nonane. The present tandem protocol has been employed to construct the tricyclic azaquaternary skeleton (ring A, B, and C) of stemonamine.
Sara Pellegrino - One of the best experts on this subject based on the ideXlab platform.
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1h azepine 2 oxo 5 amino 5 carboxylic acid a 310 helix inducer and an effective tool for functionalized gold nanoparticles
Journal of Organic Chemistry, 2015Co-Authors: Sara Pellegrino, Alessandro Moretto, Francesca Clerici, Raffaella Soave, Alessandro Contini, Andrea Bonetti, Maria Luisa GelmiAbstract:A new α,α-disubstituted constrained glutamine analogue has been designed to decorate gold nanoparticles and to induce a 310-helix when inserted in peptides. Using an efficient “one-pot” asymmetric Schmidt Reaction between 4-disubstituted-cyclohexanone and hydroxyalkylazides, 1H-azepine-2-oxo-5-amino-5-carboxylic acid was prepared. The main (R) isomer was inserted at the N-terminus in a very short peptide sequence (i.e., PhCO-(R)-Oxo-Azn-l-Ala-Aib-l-AlaNHMe) and a stable 310-helix conformation was obtained, as verified by both NMR experiments and molecular dynamics (MD) simulations. Finally, the presence of the hydroxyl chain at the nitrogen atom of the ring allowed for the preparation of covered chiral gold nanoparticles.
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1H‑Azepine-2-oxo-5-amino-5-carboxylic Acid: A 310 Helix Inducer and an Effective Tool for Functionalized Gold Nanoparticles
2015Co-Authors: Sara Pellegrino, Alessandro Moretto, Francesca Clerici, Raffaella Soave, Alessandro Contini, Andrea Bonetti, Maria Luisa GelmiAbstract:A new α,α-disubstituted constrained glutamine analogue has been designed to decorate gold nanoparticles and to induce a 310-helix when inserted in peptides. Using an efficient “one-pot” asymmetric Schmidt Reaction between 4-disubstituted-cyclohexanone and hydroxyalkylazides, 1H-azepine-2-oxo-5-amino-5-carboxylic acid was prepared. The main (R) isomer was inserted at the N-terminus in a very short peptide sequence (i.e., PhCO-(R)-Oxo-Azn-l-Ala-Aib-l-AlaNHMe) and a stable 310-helix conformation was obtained, as verified by both NMR experiments and molecular dynamics (MD) simulations. Finally, the presence of the hydroxyl chain at the nitrogen atom of the ring allowed for the preparation of covered chiral gold nanoparticles
Zhihua Chen - One of the best experts on this subject based on the ideXlab platform.
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development of the intramolecular prins cyclization Schmidt Reaction for the construction of the azaspiro 4 4 nonane application to the formal synthesis of stemonamine
ChemInform, 2011Co-Authors: Zhihua Chen, Shuyu Zhang, Fu-min ZhangAbstract:Treatment of the azide (I) with TiCl4 results in a new and efficient formation of the spiro compound (II).
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development of the intramolecular prins cyclization Schmidt Reaction for the construction of the azaspiro 4 4 nonane application to the formal synthesis of stemonamine
Organic Letters, 2011Co-Authors: Zhihua Chen, Shuyu Zhang, Fu-min ZhangAbstract:A TiCl(4)-promoted tandem intramolecular Prins cyclization/Schmidt Reaction has been designed and developed to be an efficient method for the construction of the azaspiro[4,4]nonane. The present tandem protocol has been employed to construct the tricyclic azaquaternary skeleton (ring A, B, and C) of stemonamine.