- Asymmetric synthesis of unnatural amino acids and tamsulosin chiral intermediate
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An efficient and enantioselective hydrogenation of N-acetylamino phenyl acrylic acids was successfully developed by using ruthenium catalyst. This methodology is important in the field of pharmaceuticals and provides a new process for the preparation of unnatural amino acids and tamsulosin chiral intermediate.
- Arava, Veera Reddy,Amasa, Srinivasulu Reddy,Goud Bhatthula, Bharat Kumar,Kompella, Laxmi Srinivas,Matta, Venkata Prasad,Subha
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p. 2892 - 2897
(2013/09/02)
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- Synthesis of a novel spiro bisphosphinite ligand and its application in Rh-catalyzed asymmetric hydrogenation
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A novel, chiral bisphosphinite ligand (R)-SpiroBIP has been synthesized. The rhodium complex of the ligand was found to be highly enantioselective in the asymmetric hydrogenation of α-dehydroamino acid derivatives.
- Guo, Zhenqiu,Guan, Xiaoyu,Chen, Zhiyong
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p. 468 - 473
(2007/10/03)
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- Electronic and steric effects of ligands as control elements for rhodium-catalyzed asymmetric hydrogenation
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Chiral diphosphine ligands analogous to bdpp have been synthesized and tested in order to study the effect of the electronic nature of the ligands in Rh-catalyzed asymmetric hydrogenation of some prochiral olefins. The results are compared with those obtained with the analogous unsubstituted ligand (bdpp). The rhodium-catalyzed asymmetric hydrogenation of olefins was influenced by ligand-based electronic effects, as well as substrate based ones. Excellent ee's (up to 98.3%) have been obtained in the rhodium-catalyzed hydrogenation of (Z)-α-acetamidocinnamic acids and esters.
- Herseczki, Zsanett,Gergely, Ildiko,Hegedues, Csaba,Szoellosy, Aron,Bakos, Jozsef
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p. 1673 - 1676
(2007/10/03)
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- A chiral 1,2-bisphospholane ligand with a novel structural motif: Applications in highly enantioselective Rh-catalyzed hydrogenations
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TangPhos (1) is a highly efficient and practical ligand for asymmetric hydrogenations. High enantioselectivities and turnover numbers were observed in the Rh-catalyzed hydrogenation of α-(acylamino) acrylic acids and α-arylenamides.
- Tang, Wenjun,Zhang, Xumu
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p. 1612 - 1614
(2007/10/03)
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- Synthesis and application of (3R,4R)-3,4-bis(diphenylphosphino)tetrahydrofuran as ligand for asymmetric hydrogenation of acrylic acids
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A new, chiral bisphosphine, (3R,4R)-3,4-bis(diphenylphosphino)tetrahydrofuran (4), is synthesized in three steps from (R,R)-tartaric acid esters. With rhodium(I) complexes of 4 enantiomeric excesses of 54 to 97% are obtained on catalytic hydrogenation of 2-(acetylamino)acrylic acid, 2-(acetylamino)cinnamic acids and itaconic acid. The applied substrate/catalyst ratios were between 250:1 and 11,000:1.
- Terfort
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p. 951 - 953
(2007/10/02)
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- Efficient Asymmetric Hydrogenations of (Z)-2-Acetamidoacrylic Acid Derivatives with the Cationic Rhodium Complex of (2S,4S)-MOD-BPPM
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The preparation of (2S,4S)-MOD-BPPM ((2S,4S)-N-(t-butoxycarbonyl)-4-phosphino>-2-phosphino>methyl>pyrrolidine) and its application to highly effective asymmetric hydrogenations of (Z)-2-acetamidoacrylic acid derivatives are described.
- Takahashi, Hisashi,Achiwa, Kazuo
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p. 305 - 308
(2007/10/02)
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