The Experts below are selected from a list of 3087 Experts worldwide ranked by ideXlab platform
Donald J Darensbourg - One of the best experts on this subject based on the ideXlab platform.
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water soluble organometallic compounds 5 the regio selective catalytic hydrogenation of unsaturated aldehydes to saturated aldehydes in an aqueous two phase solvent system using 1 3 5 triaza 7 phosphaadamantane complexes of rhodium
Journal of Organometallic Chemistry, 1995Co-Authors: Donald J Darensbourg, Ferenc Joo, Nicole White Stafford, Joseph H ReibenspiesAbstract:The water-soluble phosphine complex of Rh(I), [Rh(PTAH)(PTA)2Cl]Cl(1), has been synthesized from RhCl3 and 1,3,5,-triaza-7-phosphaadamantane (PTA) in 96% ethanol. This complex is an effective catalyst for the regioselective reduction of unsaturated aldehydes to saturated aldehydes. The rate of hydrogenation of trans-cinnamaldehyde with Sodium Formate as reductant was studied as a function of catalyst, substrate, and Sodium Formate concentration. The presence of an excess of PTA was found to inhibit hydrogenations completely. This reaction was also found to be partially inhibited by cyclo-octatetraene and Hg(0), leading to the conclusion that both heterogenous and homogenous mechanisms are operating. Recycling experiments show complex 1 to be quite robust, with minimal leaching into the organic phase in a biphasic system. The complex resulting from the addition of an excess of PTA to 1, [Rh(PTAH)3(PTA)Cl]Cl3 (2) has been prepared and structurally characterized by a single crystal X-ray diffraction study. 31P and 1H NMR, IR and UV-VIS spectroscopy and pH titrametric measurements were employed to study the reactivity of the various rhodium PTA complexes in aqueous solutions.
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water soluble organometallic compounds 4 catalytic hydrogenation of aldehydes in an aqueous two phase solvent system using a 1 3 5 triaza 7 phosphaadamantane complex of ruthenium
Inorganic Chemistry, 1994Co-Authors: Donald J Darensbourg, Ferenc Joo, Michael Kannisto, Agnes KathoAbstract:The water-soluble phosphine complex of ruthenium(II), cis-RuCl 2 (PTA) 4 (3), has been prepared by the reduction of RuCl 3 in ethanol in the presence of the air-stable phosphine 1,3,5-triaza-7-phosphaadamantane (2). Complex 3 is an effective catalyst for the regioselective conversion of unsaturated aldehydes to unsaturated alcohols using a biphasic aqueous/organic medium with Sodium Formate as the source of hydrogen, thus affording facile catalyst recovery and recycle. Both aromatic and aliphatic aldehydes were reduced to the corresponding alcohols
Ferenc Joo - One of the best experts on this subject based on the ideXlab platform.
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water soluble organometallic compounds 5 the regio selective catalytic hydrogenation of unsaturated aldehydes to saturated aldehydes in an aqueous two phase solvent system using 1 3 5 triaza 7 phosphaadamantane complexes of rhodium
Journal of Organometallic Chemistry, 1995Co-Authors: Donald J Darensbourg, Ferenc Joo, Nicole White Stafford, Joseph H ReibenspiesAbstract:The water-soluble phosphine complex of Rh(I), [Rh(PTAH)(PTA)2Cl]Cl(1), has been synthesized from RhCl3 and 1,3,5,-triaza-7-phosphaadamantane (PTA) in 96% ethanol. This complex is an effective catalyst for the regioselective reduction of unsaturated aldehydes to saturated aldehydes. The rate of hydrogenation of trans-cinnamaldehyde with Sodium Formate as reductant was studied as a function of catalyst, substrate, and Sodium Formate concentration. The presence of an excess of PTA was found to inhibit hydrogenations completely. This reaction was also found to be partially inhibited by cyclo-octatetraene and Hg(0), leading to the conclusion that both heterogenous and homogenous mechanisms are operating. Recycling experiments show complex 1 to be quite robust, with minimal leaching into the organic phase in a biphasic system. The complex resulting from the addition of an excess of PTA to 1, [Rh(PTAH)3(PTA)Cl]Cl3 (2) has been prepared and structurally characterized by a single crystal X-ray diffraction study. 31P and 1H NMR, IR and UV-VIS spectroscopy and pH titrametric measurements were employed to study the reactivity of the various rhodium PTA complexes in aqueous solutions.
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water soluble organometallic compounds 4 catalytic hydrogenation of aldehydes in an aqueous two phase solvent system using a 1 3 5 triaza 7 phosphaadamantane complex of ruthenium
Inorganic Chemistry, 1994Co-Authors: Donald J Darensbourg, Ferenc Joo, Michael Kannisto, Agnes KathoAbstract:The water-soluble phosphine complex of ruthenium(II), cis-RuCl 2 (PTA) 4 (3), has been prepared by the reduction of RuCl 3 in ethanol in the presence of the air-stable phosphine 1,3,5-triaza-7-phosphaadamantane (2). Complex 3 is an effective catalyst for the regioselective conversion of unsaturated aldehydes to unsaturated alcohols using a biphasic aqueous/organic medium with Sodium Formate as the source of hydrogen, thus affording facile catalyst recovery and recycle. Both aromatic and aliphatic aldehydes were reduced to the corresponding alcohols
Michael Kannisto - One of the best experts on this subject based on the ideXlab platform.
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water soluble organometallic compounds 4 catalytic hydrogenation of aldehydes in an aqueous two phase solvent system using a 1 3 5 triaza 7 phosphaadamantane complex of ruthenium
Inorganic Chemistry, 1994Co-Authors: Donald J Darensbourg, Ferenc Joo, Michael Kannisto, Agnes KathoAbstract:The water-soluble phosphine complex of ruthenium(II), cis-RuCl 2 (PTA) 4 (3), has been prepared by the reduction of RuCl 3 in ethanol in the presence of the air-stable phosphine 1,3,5-triaza-7-phosphaadamantane (2). Complex 3 is an effective catalyst for the regioselective conversion of unsaturated aldehydes to unsaturated alcohols using a biphasic aqueous/organic medium with Sodium Formate as the source of hydrogen, thus affording facile catalyst recovery and recycle. Both aromatic and aliphatic aldehydes were reduced to the corresponding alcohols
Baigui Wang - One of the best experts on this subject based on the ideXlab platform.
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Iridium-Catalyzed Highly Enantioselective Transfer Hydrogenation of Aryl N-Heteroaryl Ketones with N-Oxide as a Removable ortho-Substituent
Organic letters, 2018Co-Authors: Qixing Liu, Wang Chunqin, Haifeng Zhou, Baigui Wang, Fu YigangAbstract:A highly enantioselective transfer hydrogenation of non-ortho-substituted aryl N-heteroaryl ketones, using readily available chiral diamine-derived iridium complex (S,S)-1f as a catalyst and Sodium Formate as a hydrogen source in a mixture of H2O/i-PrOH (v/v = 1:1) under ambient conditions, is described. The chiral aryl N-heteroaryl methanols were obtained with up to 98.2% ee by introducing an N-oxide as a removable ortho-substituent. In contrast, no more than 15.1% ee was observed in the absence of an N-oxide moiety. Furthermore, the practical utility of this protocol was also demonstrated by gram-scale asymmetric synthesis of bepotastine besilate in 51% total yield and 99.9% ee.
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Iridium-Catalyzed Highly Enantioselective Transfer Hydrogenation of Aryl N‑Heteroaryl Ketones with N‑Oxide as a Removable ortho-Substituent
2018Co-Authors: Qixing Liu, Haifeng Zhou, Baigui Wang, Chunqin Wang, Lu CaoAbstract:A highly enantioselective transfer hydrogenation of non-ortho-substituted aryl N-heteroaryl ketones, using readily available chiral diamine-derived iridium complex (S,S)-1f as a catalyst and Sodium Formate as a hydrogen source in a mixture of H2O/i-PrOH (v/v = 1:1) under ambient conditions, is described. The chiral aryl N-heteroaryl methanols were obtained with up to 98.2% ee by introducing an N-oxide as a removable ortho-substituent. In contrast, no more than 15.1% ee was observed in the absence of an N-oxide moiety. Furthermore, the practical utility of this protocol was also demonstrated by gram-scale asymmetric synthesis of bepotastine besilate in 51% total yield and 99.9% ee
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bifunctional oxo tethered ruthenium complex catalyzed asymmetric transfer hydrogenation of aryl n heteroaryl ketones
Organic Letters, 2017Co-Authors: Baigui Wang, Qixing Liu, Haifeng Zhou, Xiaolan JiangAbstract:A facile asymmetric transfer hydrogenation of ortho-substituted aryl N-heteroaryl ketones and non-ortho-substituted N-oxide of aryl N-heteroaryl ketones using a readily available oxo-tethered ruthenium complex as a catalyst and Sodium Formate as a hydrogen source in an aqueous solution has been discovered. A variety of chiral aryl N-heteroaryl methanols were obtained with up to 99.9% ee.
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Bifunctional Oxo-Tethered Ruthenium Complex Catalyzed Asymmetric Transfer Hydrogenation of Aryl N‑Heteroaryl Ketones
2017Co-Authors: Baigui Wang, Qixing Liu, Haifeng Zhou, Xiaolan JiangAbstract:A facile asymmetric transfer hydrogenation of ortho-substituted aryl N-heteroaryl ketones and non-ortho-substituted N-oxide of aryl N-heteroaryl ketones using a readily available oxo-tethered ruthenium complex as a catalyst and Sodium Formate as a hydrogen source in an aqueous solution has been discovered. A variety of chiral aryl N-heteroaryl methanols were obtained with up to 99.9% ee
Qixing Liu - One of the best experts on this subject based on the ideXlab platform.
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Iridium-Catalyzed Highly Enantioselective Transfer Hydrogenation of Aryl N-Heteroaryl Ketones with N-Oxide as a Removable ortho-Substituent
Organic letters, 2018Co-Authors: Qixing Liu, Wang Chunqin, Haifeng Zhou, Baigui Wang, Fu YigangAbstract:A highly enantioselective transfer hydrogenation of non-ortho-substituted aryl N-heteroaryl ketones, using readily available chiral diamine-derived iridium complex (S,S)-1f as a catalyst and Sodium Formate as a hydrogen source in a mixture of H2O/i-PrOH (v/v = 1:1) under ambient conditions, is described. The chiral aryl N-heteroaryl methanols were obtained with up to 98.2% ee by introducing an N-oxide as a removable ortho-substituent. In contrast, no more than 15.1% ee was observed in the absence of an N-oxide moiety. Furthermore, the practical utility of this protocol was also demonstrated by gram-scale asymmetric synthesis of bepotastine besilate in 51% total yield and 99.9% ee.
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Iridium-Catalyzed Highly Enantioselective Transfer Hydrogenation of Aryl N‑Heteroaryl Ketones with N‑Oxide as a Removable ortho-Substituent
2018Co-Authors: Qixing Liu, Haifeng Zhou, Baigui Wang, Chunqin Wang, Lu CaoAbstract:A highly enantioselective transfer hydrogenation of non-ortho-substituted aryl N-heteroaryl ketones, using readily available chiral diamine-derived iridium complex (S,S)-1f as a catalyst and Sodium Formate as a hydrogen source in a mixture of H2O/i-PrOH (v/v = 1:1) under ambient conditions, is described. The chiral aryl N-heteroaryl methanols were obtained with up to 98.2% ee by introducing an N-oxide as a removable ortho-substituent. In contrast, no more than 15.1% ee was observed in the absence of an N-oxide moiety. Furthermore, the practical utility of this protocol was also demonstrated by gram-scale asymmetric synthesis of bepotastine besilate in 51% total yield and 99.9% ee
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bifunctional oxo tethered ruthenium complex catalyzed asymmetric transfer hydrogenation of aryl n heteroaryl ketones
Organic Letters, 2017Co-Authors: Baigui Wang, Qixing Liu, Haifeng Zhou, Xiaolan JiangAbstract:A facile asymmetric transfer hydrogenation of ortho-substituted aryl N-heteroaryl ketones and non-ortho-substituted N-oxide of aryl N-heteroaryl ketones using a readily available oxo-tethered ruthenium complex as a catalyst and Sodium Formate as a hydrogen source in an aqueous solution has been discovered. A variety of chiral aryl N-heteroaryl methanols were obtained with up to 99.9% ee.
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Bifunctional Oxo-Tethered Ruthenium Complex Catalyzed Asymmetric Transfer Hydrogenation of Aryl N‑Heteroaryl Ketones
2017Co-Authors: Baigui Wang, Qixing Liu, Haifeng Zhou, Xiaolan JiangAbstract:A facile asymmetric transfer hydrogenation of ortho-substituted aryl N-heteroaryl ketones and non-ortho-substituted N-oxide of aryl N-heteroaryl ketones using a readily available oxo-tethered ruthenium complex as a catalyst and Sodium Formate as a hydrogen source in an aqueous solution has been discovered. A variety of chiral aryl N-heteroaryl methanols were obtained with up to 99.9% ee
