The Experts below are selected from a list of 1242 Experts worldwide ranked by ideXlab platform
Alexander T Radosevich - One of the best experts on this subject based on the ideXlab platform.
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ancillary tethering influences σ3 p vs σ5 p speciation and enables intermolecular s h oxidative addition to nontrigonal phosphorus compounds
Organometallics, 2020Co-Authors: Hye Won Moon, Ayan Maity, Alexander T RadosevichAbstract:The design and synthesis of a nontrigonal phosphorus(III) Triamide (2) bearing a peripheral ethylene bridge is described. By comparison to a compound lacking the ethylene bridge (1, (P{N[o-NMe-C6H4...
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round trip oxidative addition ligand metathesis and reductive elimination in a piii pv synthetic cycle
Journal of the American Chemical Society, 2020Co-Authors: Soohyun Lim, Alexander T RadosevichAbstract:A synthetic cycle for aryl C–F substitution comprising oxidative addition, ligand metathesis, and reductive elimination at a Cs-symmetric phosphorus Triamide (1, P{N[o-NMe-C6H4]2}) is reported. Rea...
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p n cooperative borane activation and catalytic hydroboration by a distorted phosphorous Triamide platform
Journal of the American Chemical Society, 2017Co-Authors: Yichun Lin, Emmanuel Hatzakis, Sean M Mccarthy, Kyle D Reichl, Ting Yi Lai, Hemant P Yennawar, Alexander T RadosevichAbstract:Studies of the stoichiometric and catalytic reactivity of a geometrically constrained phosphorous Triamide 1 with pinacolborane (HBpin) are reported. The addition of HBpin to phosphorous Triamide 1 results in cleavage of the B-H bond of pinacolborane through addition across the electrophilic phosphorus and nucleophilic N-methylanilide sites in a cooperative fashion. The kinetics of this process of were investigated by NMR spectroscopy, with the determined overall second-order empirical rate law given by ν = -k[1][HBpin], where k = 4.76 × 10-5 M-1 s-1 at 25 °C. The B-H bond activation process produces P-hydrido-1,3,2-diazaphospholene intermediate 2, which exhibits hydridic reactivity capable of reacting with imines to give phosphorous Triamide intermediates, as confirmed by independent synthesis. These phosphorous Triamide intermediates are typically short lived, evolving with elimination of the N-borylamine product of imine hydroboration with regeneration of the deformed phosphorous Triamide 1. The kinetics of this latter process are shown to be first-order, indicative of a unimolecular mechanism. Consequently, catalytic hydroboration of a variety of imine substrates can be realized with 1 as the catalyst and HBpin as the terminal reagent. A mechanistic proposal implicating a P-N cooperative mechanism for catalysis that incorporates the various independently verified stoichiometric steps is presented, and a comparison to related phosphorus-based systems is offered.
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P–N Cooperative Borane Activation and Catalytic Hydroboration by a Distorted Phosphorous Triamide Platform
2017Co-Authors: Yichun Lin, Emmanuel Hatzakis, Sean M Mccarthy, Kyle D Reichl, Ting Yi Lai, Hemant P Yennawar, Alexander T RadosevichAbstract:Studies of the stoichiometric and catalytic reactivity of a geometrically constrained phosphorous Triamide 1 with pinacolborane (HBpin) are reported. The addition of HBpin to phosphorous Triamide 1 results in cleavage of the B–H bond of pinacolborane through addition across the electrophilic phosphorus and nucleophilic N-methylanilide sites in a cooperative fashion. The kinetics of this process of were investigated by NMR spectroscopy, with the determined overall second-order empirical rate law given by ν = −k[1][HBpin], where k = 4.76 × 10–5 M–1 s–1 at 25 °C. The B–H bond activation process produces P-hydrido-1,3,2-diazaphospholene intermediate 2, which exhibits hydridic reactivity capable of reacting with imines to give phosphorous Triamide intermediates, as confirmed by independent synthesis. These phosphorous Triamide intermediates are typically short lived, evolving with elimination of the N-borylamine product of imine hydroboration with regeneration of the deformed phosphorous Triamide 1. The kinetics of this latter process are shown to be first-order, indicative of a unimolecular mechanism. Consequently, catalytic hydroboration of a variety of imine substrates can be realized with 1 as the catalyst and HBpin as the terminal reagent. A mechanistic proposal implicating a P–N cooperative mechanism for catalysis that incorporates the various independently verified stoichiometric steps is presented, and a comparison to related phosphorus-based systems is offered
Scott D. Larsen - One of the best experts on this subject based on the ideXlab platform.
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hydroxylation of enolates with oxodiperoxymolybdenum pyridine hexamethylphosphoric Triamide moo5 py hmpa mooph 3 hydroxy 1 7 7 trimethylbicyclo 2 2 1 heptan 2 one
Organic Syntheses, 2003Co-Authors: Edwin Vedejs, Scott D. LarsenAbstract:Hydroxylation of enolates with oxodiperoxymolybdenum(pyridine)(hexamethylphosphoric Triamide), MoO5·Py·HMPA(MoOPH): 3-hydroxy-1,7,7-trimethylbicyclo[2.2.1]heptan-2-one intermediate: Oxodiperoxymolybdenum(aqua)(hexamethylphosphoric Triamide), MoO5·H2O·HMPA intermediate: Oxodiperoxymolybdenum(pyridine)(hexamethylphosphoric Triamide) MoO5·Py·HMPAMoOPH product: 1,7,7-trimethyl-3-hydroxybicyclo[2.2.1]-heptan-2-one Keywords: hydroxylation; oxidation, CH2 CHOH and CHOR; lithium diisopropylamide (LDA), preparation of; pyridine; tetrahydrofuran; hexamethylphosphoric Triamide (HMPA), toxicity; methanol; MoOPH
Edwin Vedejs - One of the best experts on this subject based on the ideXlab platform.
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hydroxylation of enolates with oxodiperoxymolybdenum pyridine hexamethylphosphoric Triamide moo5 py hmpa mooph 3 hydroxy 1 7 7 trimethylbicyclo 2 2 1 heptan 2 one
Organic Syntheses, 2003Co-Authors: Edwin Vedejs, Scott D. LarsenAbstract:Hydroxylation of enolates with oxodiperoxymolybdenum(pyridine)(hexamethylphosphoric Triamide), MoO5·Py·HMPA(MoOPH): 3-hydroxy-1,7,7-trimethylbicyclo[2.2.1]heptan-2-one intermediate: Oxodiperoxymolybdenum(aqua)(hexamethylphosphoric Triamide), MoO5·H2O·HMPA intermediate: Oxodiperoxymolybdenum(pyridine)(hexamethylphosphoric Triamide) MoO5·Py·HMPAMoOPH product: 1,7,7-trimethyl-3-hydroxybicyclo[2.2.1]-heptan-2-one Keywords: hydroxylation; oxidation, CH2 CHOH and CHOR; lithium diisopropylamide (LDA), preparation of; pyridine; tetrahydrofuran; hexamethylphosphoric Triamide (HMPA), toxicity; methanol; MoOPH
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oxodiperoxymolybdenum pyridine hexamethylphosphoric Triamide
e-EROS Encyclopedia of Reagents for Organic Synthesis, 2001Co-Authors: Edwin VedejsAbstract:[23319-63-3] C11H23MoN4O6P (MW 434.29) InChI = 1S/C6H18N3OP.C5H5N.Mo.2O2.O/c1-7(2)11(10,8(3)4)9(5)6;1-2-4-6-5-3-1;;2*1-2;/h1-6H3;1-5H;;;;/q;;+4;2*-2; InChIKey = PPRBHGIGPWBROO-UHFFFAOYSA-N (hydroxylation of enolates1 and nitrile anions;2 preparation of carbonyl compounds by oxidative degradation of anions of sulfones;3 nitroalkanes;4 phosphonates;5 for N-hydroxylation of amides;6 for oxidative cleavage of CB bonds7) Alternate Name: MoOPH. Physical Data: mp 103–105 °C (dec). Solubility: insol ether; sparingly sol THF; sol dichloromethane. Form Supplied in: finely divided yellow crystals; not available commercially. Analysis of Reagent Purity: no convenient assay has been reported. Decomposition is indicated if the reagent smells of pyridine or becomes sticky.1b Preparative Methods: a detailed procedure is available:1b (1) MoO3 + 30% H2O2 (<40 °C); (2) add HMPA; vacuum dry MoO5ċHMPAċH2O to MoO5ċHMPA; (3) pyridine in THF gives MoOPH. Purification: attempted recrystallization causes decomposition of MoOPH. Purity depends on the quality of MoO5ċHMPAċH2O, which can be recrystallized from methanol. Handling, Storage, and Precautions: MoOPH should be stored in the freezer and protected from light.1b The reagent should be treated as an explosion hazard due to its peroxidic nature.1b,8 Properly stored MoOPH is a freely flowing, yellow crystalline powder, and can be handled in the air at room temperature using a safety shield and protective gloves.
Yichun Lin - One of the best experts on this subject based on the ideXlab platform.
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p n cooperative borane activation and catalytic hydroboration by a distorted phosphorous Triamide platform
Journal of the American Chemical Society, 2017Co-Authors: Yichun Lin, Emmanuel Hatzakis, Sean M Mccarthy, Kyle D Reichl, Ting Yi Lai, Hemant P Yennawar, Alexander T RadosevichAbstract:Studies of the stoichiometric and catalytic reactivity of a geometrically constrained phosphorous Triamide 1 with pinacolborane (HBpin) are reported. The addition of HBpin to phosphorous Triamide 1 results in cleavage of the B-H bond of pinacolborane through addition across the electrophilic phosphorus and nucleophilic N-methylanilide sites in a cooperative fashion. The kinetics of this process of were investigated by NMR spectroscopy, with the determined overall second-order empirical rate law given by ν = -k[1][HBpin], where k = 4.76 × 10-5 M-1 s-1 at 25 °C. The B-H bond activation process produces P-hydrido-1,3,2-diazaphospholene intermediate 2, which exhibits hydridic reactivity capable of reacting with imines to give phosphorous Triamide intermediates, as confirmed by independent synthesis. These phosphorous Triamide intermediates are typically short lived, evolving with elimination of the N-borylamine product of imine hydroboration with regeneration of the deformed phosphorous Triamide 1. The kinetics of this latter process are shown to be first-order, indicative of a unimolecular mechanism. Consequently, catalytic hydroboration of a variety of imine substrates can be realized with 1 as the catalyst and HBpin as the terminal reagent. A mechanistic proposal implicating a P-N cooperative mechanism for catalysis that incorporates the various independently verified stoichiometric steps is presented, and a comparison to related phosphorus-based systems is offered.
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P–N Cooperative Borane Activation and Catalytic Hydroboration by a Distorted Phosphorous Triamide Platform
2017Co-Authors: Yichun Lin, Emmanuel Hatzakis, Sean M Mccarthy, Kyle D Reichl, Ting Yi Lai, Hemant P Yennawar, Alexander T RadosevichAbstract:Studies of the stoichiometric and catalytic reactivity of a geometrically constrained phosphorous Triamide 1 with pinacolborane (HBpin) are reported. The addition of HBpin to phosphorous Triamide 1 results in cleavage of the B–H bond of pinacolborane through addition across the electrophilic phosphorus and nucleophilic N-methylanilide sites in a cooperative fashion. The kinetics of this process of were investigated by NMR spectroscopy, with the determined overall second-order empirical rate law given by ν = −k[1][HBpin], where k = 4.76 × 10–5 M–1 s–1 at 25 °C. The B–H bond activation process produces P-hydrido-1,3,2-diazaphospholene intermediate 2, which exhibits hydridic reactivity capable of reacting with imines to give phosphorous Triamide intermediates, as confirmed by independent synthesis. These phosphorous Triamide intermediates are typically short lived, evolving with elimination of the N-borylamine product of imine hydroboration with regeneration of the deformed phosphorous Triamide 1. The kinetics of this latter process are shown to be first-order, indicative of a unimolecular mechanism. Consequently, catalytic hydroboration of a variety of imine substrates can be realized with 1 as the catalyst and HBpin as the terminal reagent. A mechanistic proposal implicating a P–N cooperative mechanism for catalysis that incorporates the various independently verified stoichiometric steps is presented, and a comparison to related phosphorus-based systems is offered
Philip A Gale - One of the best experts on this subject based on the ideXlab platform.
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anion recognition and transport properties of sulfamide phosphoric Triamide and thiophosphoric Triamide based receptors
Chemical Communications, 2013Co-Authors: Philippa B Cranwell, Jennifer R Hiscock, Cally J E Haynes, Mark E Light, Neil J Wells, Philip A GaleAbstract:Studies of sulfamide, phosphoric Triamide and thiophosphoric Triamide-based organocatalysts show that the phosphorus containing systems are effective new hydrogen bonding motifs for the recognition and transport of anions.
