The Experts below are selected from a list of 6 Experts worldwide ranked by ideXlab platform

Tao Tang - One of the best experts on this subject based on the ideXlab platform.

  • controlled chain scission of polybutadiene by the Schwartz Hydrozirconation
    Chemistry: A European Journal, 2013
    Co-Authors: Jun Zheng, Yanhui Wang, Tao Tang
    Abstract:

    Controlled chain-scission of polybutadiene (PB), polyisoprene, and poly(styrene-co-butadiene), induced by bis(cyclopentadienyl) zirconium hydrochloride (Cp2ZrHCl), was revealed at room temperature. The chain-scission reaction of linear PB was studied by means of GPC, NMR spectroscopy, and MALDI-TOF-MS. It was confirmed that the molecular weights of degraded products were quasi-quantitatively controlled by Cp2ZrHCl loading, irrespective of the starting PB, whereas the microstructure of PB chains was crucial to the scission reaction. The Hydrozirconation of model molecules indicated that the existence of an internal double bond in compounds with multiple double bonds was essential for chain cleavage. The chain-cleavage mechanism was proposed to involve Hydrozirconation of internal double bonds in PB chains and beta-alkyl elimination. Furthermore, metallocene-catalyzed chain-scission by a chain-transfer reaction was developed. It is believed that the reported chain scission offers a promising pathway for end-group functionalization by chain cleavage and presents a new application of Schwartz's reagent.

Jun Zheng - One of the best experts on this subject based on the ideXlab platform.

  • controlled chain scission of polybutadiene by the Schwartz Hydrozirconation
    Chemistry: A European Journal, 2013
    Co-Authors: Jun Zheng, Yanhui Wang, Tao Tang
    Abstract:

    Controlled chain-scission of polybutadiene (PB), polyisoprene, and poly(styrene-co-butadiene), induced by bis(cyclopentadienyl) zirconium hydrochloride (Cp2ZrHCl), was revealed at room temperature. The chain-scission reaction of linear PB was studied by means of GPC, NMR spectroscopy, and MALDI-TOF-MS. It was confirmed that the molecular weights of degraded products were quasi-quantitatively controlled by Cp2ZrHCl loading, irrespective of the starting PB, whereas the microstructure of PB chains was crucial to the scission reaction. The Hydrozirconation of model molecules indicated that the existence of an internal double bond in compounds with multiple double bonds was essential for chain cleavage. The chain-cleavage mechanism was proposed to involve Hydrozirconation of internal double bonds in PB chains and beta-alkyl elimination. Furthermore, metallocene-catalyzed chain-scission by a chain-transfer reaction was developed. It is believed that the reported chain scission offers a promising pathway for end-group functionalization by chain cleavage and presents a new application of Schwartz's reagent.

Yanhui Wang - One of the best experts on this subject based on the ideXlab platform.

  • controlled chain scission of polybutadiene by the Schwartz Hydrozirconation
    Chemistry: A European Journal, 2013
    Co-Authors: Jun Zheng, Yanhui Wang, Tao Tang
    Abstract:

    Controlled chain-scission of polybutadiene (PB), polyisoprene, and poly(styrene-co-butadiene), induced by bis(cyclopentadienyl) zirconium hydrochloride (Cp2ZrHCl), was revealed at room temperature. The chain-scission reaction of linear PB was studied by means of GPC, NMR spectroscopy, and MALDI-TOF-MS. It was confirmed that the molecular weights of degraded products were quasi-quantitatively controlled by Cp2ZrHCl loading, irrespective of the starting PB, whereas the microstructure of PB chains was crucial to the scission reaction. The Hydrozirconation of model molecules indicated that the existence of an internal double bond in compounds with multiple double bonds was essential for chain cleavage. The chain-cleavage mechanism was proposed to involve Hydrozirconation of internal double bonds in PB chains and beta-alkyl elimination. Furthermore, metallocene-catalyzed chain-scission by a chain-transfer reaction was developed. It is believed that the reported chain scission offers a promising pathway for end-group functionalization by chain cleavage and presents a new application of Schwartz's reagent.

I. Namboothiri - One of the best experts on this subject based on the ideXlab platform.

  • SAEGUSA Enone Synthesis to SZARVASY–SCHÖPF Carbomethoxylation
    Organic Syntheses Based on Name Reactions, 2012
    Co-Authors: Alfred Hassner, I. Namboothiri
    Abstract:

    This article contains brief overviews, mechanisms and practical details for organic synthesis named reactions and processes beginning with the letter ‘S’. Reactions included in this section are: SAEGUSA Enone Synthesis; SAKURAI Allylation via Allylsilanes; SANDMEYER Isatin Synthesis; SANDMEYER–GATTERMANN Aromatic Substitution; SANGER Amino Acid Labeling Reagent; SARETT Cr Oxidizing Reagent; SCHEINER Aziridine Triazoline Synthesis; SCHENCK Allylic Oxidation; SCHIEMANN Aromatic Fluorination; SCHMIDT Rearrangement via Azides; SCHMITZ Diaziridine Synthesis; SCHOLL Polyaromatic Synthesis; SCHOLLKOPF Amino Acid Synthesis; SCHOLLKOPF–BARTON–ZARD Pyrrole Synthesis; SCHOLTZ Indolizine Synthesis; SCHOTTEN–BAUMANN Alcohol and Amine Acylation; Schwartz Hydrozirconation; SCHWEIZER Allylamine Synthesis; SCHWEIZER Allenyl Azine Rearrangement; SCHWESINGER Phosphazene Bases; SEEBACH Chiral Oxazolidinones; SEEBACH–BECK TADDOL Reagent; SEEBACH–COREY Dithiane Reagents; SEMMLER–WOLFF Oxime Aromatization; SEYFERTH Acyllithium Reagent; SEYFERTH Dihalocarbene Reagent; SEYFERTH – GILBERT Diazoalkane Reagent; SHAPIRO Olefination via Tosylhydrazones; SHARPLESS Allylic Amination; SHARPLESS Asymmetric Dihydroxylation; SHARPLESS Asymmetric Epoxidation; SHEEHAN Carbodiimide Coupling Reagent; SHERADSKY – ENDO Hetero-Cope Rearrangement; SHESTAKOV Hydrazino Acid Synthesis; SHEVERDINA–KOCHESHKOV Electrophilic Amination; SHIBASAKI Ti–N Complex; SIEGRIST Stilbene Synthesis; SIMCHEN Azaheterocycle Synthesis; SIMMONS – SMITH Cyclopropanation; SIMONIS Benzopyrone Synthesis; SKATTEBOL Vinyldihalocyclopropane Rearrangement; SKRAUP Quinoline Synthesis; SMILES Aromatic Rearrangement; SMITH–MIDDLETON–ROZEN Fluorination; SNIECKUS Carbamate Rearrangement; SODERQUIST Boranes; SOMMELET Aldehyde Synthesis; SOMMELET Ammonium Ylide Rearrangement; SONN – MULLER Aldehyde Synthesis; SONOGASHIRA Acetylene Coupling; SOULA Phase Transfer Catalyst; SPECKAMP Acyliminium Ions; SPENGLER–PFANNENSTIEL Sugar Oxidation; SREBNIK–QUNTAR Cyclopropyl Phosphonates; STAAB Carbonylimidazole; STAUDINGER Azide Reduction; STAUDINGER Ketene Cycloadditions; STAUDINGER – PFENNINGER Thiirane Dioxide Synthesis; STEGLICH – HASSNER Direct Alcohol Esterification; STEPHEN Aldehyde Synthesis; STEPHENS–CASTRO Acetylene Coupling; STETTER 1,4-Dicarbonyl Synthesis; STEVENS Ammonium Ylide Rearrangement; STIEGLITZ N -Haloamine Rearrangement; STILES–SISTI Grignard Formylation; STILLE Carbonyl Synthesis; STILLE Cross Coupling; STILL–GENNARI Z-Olefin Synthesis; STOBBE Succinic Ester Condensation; STOLTZ Asymmetric Ketone α-Allylation; STORK–HUNIG Cyanohydrin Alkylation; STORK Enamine Alkylation; STORK Radical Cyclization; STORK Reductive Cyclization; STORK–HAUSER Aminonitrile Alkylation; STORK–ZHAO Z -Iodo-olefin Synthesis; STORY Macrocycle Synthesis; STRECKER Aminoacid Synthesis; STRYKER Regioselective Reduction; SUAREZ Photochemical lodo Functionalization; SUZUKI Aromatic Nitration; SUZUKI Selective Nitrile Reduction; SUZUKI–MIYAURA C C Coupling; SWARTS Fluoroalkane Synthesis; SWERN Alcohol Oxidation; SZARVASY–SCHOPF Carbomethoxylation

Alfred Hassner - One of the best experts on this subject based on the ideXlab platform.

  • SAEGUSA Enone Synthesis to SZARVASY–SCHÖPF Carbomethoxylation
    Organic Syntheses Based on Name Reactions, 2012
    Co-Authors: Alfred Hassner, I. Namboothiri
    Abstract:

    This article contains brief overviews, mechanisms and practical details for organic synthesis named reactions and processes beginning with the letter ‘S’. Reactions included in this section are: SAEGUSA Enone Synthesis; SAKURAI Allylation via Allylsilanes; SANDMEYER Isatin Synthesis; SANDMEYER–GATTERMANN Aromatic Substitution; SANGER Amino Acid Labeling Reagent; SARETT Cr Oxidizing Reagent; SCHEINER Aziridine Triazoline Synthesis; SCHENCK Allylic Oxidation; SCHIEMANN Aromatic Fluorination; SCHMIDT Rearrangement via Azides; SCHMITZ Diaziridine Synthesis; SCHOLL Polyaromatic Synthesis; SCHOLLKOPF Amino Acid Synthesis; SCHOLLKOPF–BARTON–ZARD Pyrrole Synthesis; SCHOLTZ Indolizine Synthesis; SCHOTTEN–BAUMANN Alcohol and Amine Acylation; Schwartz Hydrozirconation; SCHWEIZER Allylamine Synthesis; SCHWEIZER Allenyl Azine Rearrangement; SCHWESINGER Phosphazene Bases; SEEBACH Chiral Oxazolidinones; SEEBACH–BECK TADDOL Reagent; SEEBACH–COREY Dithiane Reagents; SEMMLER–WOLFF Oxime Aromatization; SEYFERTH Acyllithium Reagent; SEYFERTH Dihalocarbene Reagent; SEYFERTH – GILBERT Diazoalkane Reagent; SHAPIRO Olefination via Tosylhydrazones; SHARPLESS Allylic Amination; SHARPLESS Asymmetric Dihydroxylation; SHARPLESS Asymmetric Epoxidation; SHEEHAN Carbodiimide Coupling Reagent; SHERADSKY – ENDO Hetero-Cope Rearrangement; SHESTAKOV Hydrazino Acid Synthesis; SHEVERDINA–KOCHESHKOV Electrophilic Amination; SHIBASAKI Ti–N Complex; SIEGRIST Stilbene Synthesis; SIMCHEN Azaheterocycle Synthesis; SIMMONS – SMITH Cyclopropanation; SIMONIS Benzopyrone Synthesis; SKATTEBOL Vinyldihalocyclopropane Rearrangement; SKRAUP Quinoline Synthesis; SMILES Aromatic Rearrangement; SMITH–MIDDLETON–ROZEN Fluorination; SNIECKUS Carbamate Rearrangement; SODERQUIST Boranes; SOMMELET Aldehyde Synthesis; SOMMELET Ammonium Ylide Rearrangement; SONN – MULLER Aldehyde Synthesis; SONOGASHIRA Acetylene Coupling; SOULA Phase Transfer Catalyst; SPECKAMP Acyliminium Ions; SPENGLER–PFANNENSTIEL Sugar Oxidation; SREBNIK–QUNTAR Cyclopropyl Phosphonates; STAAB Carbonylimidazole; STAUDINGER Azide Reduction; STAUDINGER Ketene Cycloadditions; STAUDINGER – PFENNINGER Thiirane Dioxide Synthesis; STEGLICH – HASSNER Direct Alcohol Esterification; STEPHEN Aldehyde Synthesis; STEPHENS–CASTRO Acetylene Coupling; STETTER 1,4-Dicarbonyl Synthesis; STEVENS Ammonium Ylide Rearrangement; STIEGLITZ N -Haloamine Rearrangement; STILES–SISTI Grignard Formylation; STILLE Carbonyl Synthesis; STILLE Cross Coupling; STILL–GENNARI Z-Olefin Synthesis; STOBBE Succinic Ester Condensation; STOLTZ Asymmetric Ketone α-Allylation; STORK–HUNIG Cyanohydrin Alkylation; STORK Enamine Alkylation; STORK Radical Cyclization; STORK Reductive Cyclization; STORK–HAUSER Aminonitrile Alkylation; STORK–ZHAO Z -Iodo-olefin Synthesis; STORY Macrocycle Synthesis; STRECKER Aminoacid Synthesis; STRYKER Regioselective Reduction; SUAREZ Photochemical lodo Functionalization; SUZUKI Aromatic Nitration; SUZUKI Selective Nitrile Reduction; SUZUKI–MIYAURA C C Coupling; SWARTS Fluoroalkane Synthesis; SWERN Alcohol Oxidation; SZARVASY–SCHOPF Carbomethoxylation