- Monohydride-Dichloro Rhodium(III) Complexes with Chiral Diphosphine Ligands as Catalysts for Asymmetric Hydrogenation of Olefinic Substrates
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We report full details of the synthesis and characterization of monohydride-dichloro rhodium(III) complexes bearing chiral diphosphine ligands, such as (S)-BINAP, (S)-DM-SEGPHOS, and (S)-DTBM-SEGPHOS, producing cationic triply chloride bridged dinuclear rhodium(III) complexes (1 a: (S)-BINAP; 1 b: (S)-DM-SEGPHOS) and a neutral mononuclear monohydride-dichloro rhodium(III) complex (1 c: (S)-DTBM-SEGPHOS) in high yield and high purity. Their solid state structure and solution behavior were determined by crystallographic studies as well as full spectral data, including DOSY NMR spectroscopy. Among these three complexes, 1 c has a rigid pocket surrounded by two chloride atoms bound to the rhodium atom together with one tBu group of (S)-DTBM-SEGPHOS for fitting to simple olefins without any coordinating functional groups. Complex 1 c exhibited superior catalytic activity and enantioselectivity for asymmetric hydrogenation of exo-olefins and olefinic substrates. The catalytic activity of 1 c was compared with that of well-demonstrated dihydride species derived in situ from rhodium(I) precursors such as [Rh(cod)Cl]2 and [Rh(cod)2]+[BF4]? upon mixing with (S)-DTBM-SEGPHOS under dihydrogen.
- Higashida, Kosuke,Brüning, Fabian,Tsujimoto, Nagataka,Higashihara, Kenya,Nagae, Haruki,Togni, Antonio,Mashima, Kazushi
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p. 8749 - 8759
(2020/07/04)
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- PtCl4-catalyzed cyclization of N-acetyl-2-alkynylanilines: A mild and efficient synthesis of N-acetyl-2-substituted indoles
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An efficient synthesis of N-acetyl-2-substituted indole derivatives via direct intramolecular hydroamination of N-acetyl-2-alkynylaniline derivatives was developed. The reaction could be applied to a wide range of substrates employing only 1–2 mol% of PtCl4 as the catalyst to furnish the desired indole products in moderate to excellent yields. The current protocol is efficient, reliable and scalable, and could serve as an important tool for convenient and rapid access to this important class of N-heterocyclic skeleton from readily available substrates.
- Chaisan, Nattawadee,Kaewsri, Wilailak,Thongsornkleeb, Charnsak,Tummatorn, Jumreang,Ruchirawat, Somsak
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p. 675 - 680
(2018/01/18)
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- Multicatalytic one-pot reaction of 1-(2-alkynylphenyl)ketoximes for generation of indole derivatives
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Multicatalytic one-pot Beckmann rearrangement/intramolecular cyclization/halogenation reaction of 1-(2-alkynylphenyl)ketoxime is reported, leading to the expected indole derivatives in good yield.
- Qiu, Guanyinsheng,Ding, Qiuping,Ren, Hui,Peng, Yiyuan,Wu, Jie
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supporting information; experimental part
p. 3975 - 3977
(2010/11/04)
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- Methods and systems for preparing fused heterocyclic compounds using copper(I) catalysts
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A copper(I)-catalyzed procedure for the synthesis of benzo[b]heterocycles. This protocol can be used to synthesize a variety of 2-arylbenzo[b]furans and indoles in good to excellent yields. This method can tolerate a variety of functional groups, does not require the use of expensive additives and is palladium-free.
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Page/Page column 13; 27-28
(2009/01/24)
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- Copper(I)-catalyzed coupling of terminal acetylenes with aryl or vinyl halides
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Synthetic protocols using copper(I) catalysts for the formation of diaryl acetylenes, 1,3-enynes, benzofurans and indoles are described. Georg Thieme Verlag Stuttgart.
- Saejueng, Pranorm,Bates, Craig G.,Venkataraman
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p. 1706 - 1712
(2007/10/03)
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- New synthesis of benzo[b]furan and indole derivatives from 1,1-dibromo-1-alkenes using a tandem Pd-assisted cyclization-coupling reaction
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We report a new flexible method for the synthesis of 2-functionalized benzo[b]furans and indoles from readily available o-(2,2-dibromovinyl)-phenol, -aniline or -acetanilide using a tandem Pd-assisted cyclization-coupling reaction.
- Thielges, Sabine,Meddah, Emilie,Bisseret, Philippe,Eustache, Jacques
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p. 907 - 910
(2007/10/03)
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