- Selective Rhodium-Catalyzed Hydroformylation of Terminal Arylalkynes and Conjugated Enynes to (Poly)enals Enabled by a π-Acceptor Biphosphoramidite Ligand
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The hydroformylation of terminal arylalkynes and enynes offers a straightforward synthetic route to the valuable (poly)enals. However, the hydroformylation of terminal alkynes has remained a long-standing challenge. Herein, an efficient and selective Rh-catalyzed hydroformylation of terminal arylalkynes and conjugated enynes has been achieved by using a new stable biphosphoramidite ligand with strong π-acceptor capacity, which affords various important E-(poly)enals in good yields with excellent chemo- and regioselectivity at low temperatures and low syngas pressures.
- Zhao, Jiangui,Zheng, Xueli,Tao, Shaokun,Zhu, Yuxin,Yi, Jiwei,Tang, Songbai,Li, Ruixiang,Chen, Hua,Fu, Haiyan,Yuan, Maolin
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supporting information
p. 6067 - 6072
(2021/08/16)
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- Preparation method of biphenyl tetradentate phosphite ligand
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The invention discloses a preparation method of a novel biphenyl tetradentate phosphite ligand 2,2',6,6'-tetra [(1,1'-biphenyl-2,2'-diyl) phosphite]-3,3',5,5'-tetra-tert-butyl-1,1'-biphenyl and derivatives thereof. The novel biphenyl tetradentate phosphite ligand has a structure as shown in a general formula I, wherein a substituent R in the general formula I can be a cyclic phosphine structure. The novel biphenyl tetradentate phosphite ligand has good conversion rate and normal-to-isomeric ratio in a mixed/etherified C4 (butylene) hydroformylation reaction system.
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Paragraph 0022-0025
(2020/11/23)
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- Hydroxylated biphenyls as tyrosinase inhibitor: A spectrophotometric and electrochemical study
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A small collection of C2-symmetry hydroxylated biphenyls was prepared by straightforward methods and the capability to act as inhibitors of tyrosinase has been evaluated by both spectrophotometric and electrochemical assays. Our attention was f
- Ruzza, Paolo,Serra, Pier Andrea,Fabbri, Davide,Dettori, Maria Antonietta,Rocchitta, Gaia,Delogu, Giovanna
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supporting information
p. 1034 - 1038
(2016/12/26)
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- New tetraphosphite ligands for regioselective linear hydroformylation of terminal and internal olefins
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We successfully developed new tetraphosphite ligands L1-L5 and applied them to the rhodium-catalyzed hydroformylation of terminal and internal olefins. High catalytic reactivities and excellent regioselectivities for linear aldehydes were obtained in the rhodium-catalyzed hydroformylation of simple olefins (l/b ratio up to 90, 98.9% linear selectivity, 99.2% conversion) using the tetraphosphite ligand L2. And the tetraphosphite ligand L2 also displayed moderate to good linear regioselectivities for challenging substrates styrene and internal olefin 2-octene.
- Zhang, Zongpeng,Chen, Caiyou,Wang, Qian,Han, Zhengyu,Dong, Xiu-Qin,Zhang, Xumu
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p. 14559 - 14562
(2016/02/19)
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- P(O)R2-directed Pd-catalyzed C-H functionalization of biaryl derivatives to synthesize chiral phosphorous ligands
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Chiral phosphorus ligands have been widely used in transition metal-catalyzed asymmetric reactions. Herein, we report a new synthesis approach of chiral biaryls containing a phosphorus moiety using P(O)R 2-directed Pd-catalyzed C-H activation; the functionalized products are produced with good enantioselectivity.
- Hu, Rong-Bin,Wang, Hong-Li,Zhang, Hong-Yu,Zhang, Heng,Ma, Yan-Na,Yang, Shang-Dong
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supporting information
p. 2071 - 2076
(2014/11/08)
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- Highly enantioselective copper-catalyzed allylic alkylation with atropos phosphoramidites bearing a D2-symmetric biphenyl backbone
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A novel class of atropos dibridged biphenyl phosphoramidites bearing a D2-symmetric biphenyl backbone was prepared and applied as chiral ligands in the copper-catalyzed allylic alkylation with Grignard reagent. The alkylation products were obtained in quantitative yields with high regioselectivities up to 94:6 of SN2′/SN2 ratio and enantiomeric excesses up to 91.1% for SN2′ products. The unique D2-symmetric backbone ligands have the advantages of easy preparation and sufficient reusability of their key intermediates from the undesired isomers.
- Fang, Fang,Zhang, Hui,Xie, Fang,Yang, Guoqiang,Zhang, Wanbin
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experimental part
p. 3593 - 3598
(2010/06/21)
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- Highly regioselective isomerization - Hydroformylation of internal olefins to linear aldehyde using rh complexes with tetraphosphorus ligands
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(Figure Presented) A series of new pyrrole-based tetraphosphorus ligands were synthesized and used for Rh-catalyzed isomerization-hydroformylation of internal olefins. It was found that the substituents at the 3,3′,5, 5′-positions of the biphenyl greatly effected the linear selectivity, and the alkyl-substituted tetraphosphorus ligands gave the best results (for 2-octene, n:i up to 207, for 2-hexene, n:i up to 362).
- Yu, Shichao,Chie, Yu-Ming,Guan, Zheng-Hui,Zhang, Xumu
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scheme or table
p. 3469 - 3472
(2009/05/07)
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- Chiral Biphenyl Bis(crown ethers): Synthesis and Resolution
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New chiral bis(crown ethers) with a central 2,2',6,6'-tetraoxybiphenyl unit have been prepared and resolved.Their complexing properties and absolute configuration are discussed.
- Lindsten, Goeran,Wennerstroem, Olof,Isaksson, Roland
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p. 547 - 554
(2007/10/02)
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