- Iridium-Catalysed Reductive Deoxygenation of Ketones with Formic Acid as Traceless Hydride Donor
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An iridium-catalysed deoxygenation of ketones and aldehydes is achieved, with formic acid as hydride donor and water as co-solvent. At low catalyst loading, a number of 4-(N,N-disubstituted amino) aryl ketones are readily deoxygenated in excellent yields and chemoselectivity. Numerous functional groups, especially phenolic and alcoholic hydroxyls, secondary amine, carboxylic acid, and alkyl chloride, are well tolerable. Geminally dideuterated alkanes are obtained with up to 90% D incorporation, when DCO2D and D2O are used in place of their hydrogenative counterparts. The activating 4-(N,N-disubstituted amino)aryl groups have been demonstrated to undergo a variety of useful transformations. The deoxygenative deuterations have been used to prepare a deuterated drug molecule Chlorambucil-4,4-d2. (Figure presented.).
- Yang, Zhiheng,Zhu, Xueya,Yang, Shiyi,Cheng, Weiyan,Zhang, Xiaojian,Yang, Zhanhui
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supporting information
p. 5496 - 5505
(2020/10/22)
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- Iridium-Catalyzed Highly Efficient and Site-Selective Deoxygenation of Alcohols
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An iridium-catalyzed, highly efficient, and site-selective deoxygenation of primary, secondary, and tertiary alcohols has been realized, under the assistance of a 4-(N-substituted amino)aryl directing group. Only the hydroxyl adjacent to the directing group can be deoxygenated. The deoxygenation is performed in water, with formic acid as both the promoter and hydride donor. Excellent yields and functionality tolerance, as well as high efficiency (S/C up to 1000 000, TOF up to 445 000 h-1), are obtained. The kinetic isotope effect studies show that hydride formation is the rate-determining step, and the deoxygenation follows an SN1-type pathway. The deoxygenation protocol has been demonstrated useful in the structural modification of naturally occurring ketones and steroids.
- Yang, Shiyi,Tang, Weiping,Yang, Zhanhui,Xu, Jiaxi
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p. 9320 - 9326
(2018/09/21)
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- Efficient N-heterocyclic carbene nickel pincer complexes catalyzed cross coupling of benzylic ammonium salts with boronic acids
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Pyridine-bridged bis-benzimidazolylidene nickel complexes exhibited very high catalytic activity toward cross coupling of inactive (hetero)aryl benzylic ammonium salts with (hetero)aryl and alkenyl boronic acids under mild reaction conditions. Even at 2 mol% catalyst loading, a wide range of substrates for both coupling partners with different steric and electronic properties were well tolerated.
- Liu, Xi-Yu,Zhu, Hai-Bo,Shen, Ya-Jing,Jiang, Jian,Tu, Tao
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p. 350 - 353
(2017/01/28)
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- Disproportionation reaction of diarylmethylisopropyl ethers: a versatile access to diarylmethanes from diarylcarbinols speeded up by the use of microwave irradiation
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An efficient synthesis of diarylmethanes under classical thermal conditions and under microwave heating is described from diarylcarbinols via a new disproportionation reaction. The key step involves a selective hydride transfer of isopropyl ether intermed
- L'Hermite, Nathalie,Giraud, Anne,Provot, Olivier,Peyrat, Jean-Fran?ois,Alami, Mouad,Brion, Jean-Daniel
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p. 11994 - 12002
(2007/10/03)
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- Thermal rearrangement of N-benzylanilinium hexafluoroantimonates
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We prepared p-substituted N-benzylanilinium hexafluoroantimonates, known cationic initiators, and examined their thermal reaction. The thermal reaction produced 2- or 4-benzylanilinium salts as the major products, which resulted from the rearrangement of the benzyl group. The reaction proceeded at lower temperature with higher yield when the substituent in the benzyl group was electron donating.
- Park, Jeongkyu,Shin, Jung-Hyu,Lee, Changjin
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p. 7485 - 7488
(2007/10/03)
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