- Nickel-catalyzed reduction of ketones with water and triethylsilane
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The acetophenone (1a) reduction using catalytically active nickel complexes and water is an efficient and sustainable method to access a new methodology of transfer hydrogenation of ketones. When triethylsilane (Et3SiH) was used as sacrificial agent to promote the transfer hydrogenation from water, 1-phenylethanol (2a) was obtained in excellent yield along with silanol (Et3SiOH) as the reaction's driving force. Deuterium labeling studies were made using Et3SiD or D2O and these studies showed that both compounds participate as hydride sources for the ketone reduction. A scope of substrates was assessed, including a variety of mono/diketones, and α,β-unsaturated ketones, to yield the corresponding secondary alcohols and saturated ketones. Additionally, asymmetric transfer hydrogenation of mono-ketones was studied for the mixture of nickel/(bisphosphine or phospholane) as catalyst precursor, using H2O/Et3SiO system and ethanol as hydrogen sources.
- Castellanos-Blanco, Nahury,Flores-Alamo, Marcos,García, Juventino J.
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- Tandem hydrogenation and condensation of fluorinated α,β-unsaturated ketones with primary amines, catalyzed by nickel
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A simple homogeneous catalytic system based on nickel phosphine complexes has been developed for the transfer hydrogenation and condensation of α,β-unsaturated ketones to yield saturated ones and saturated imines using primary amines as hydrogen donors. Thus, a wide range of fluorinated 1,5-diaryl-1,4-pentadiene-3-ones were allowed to react with substituted benzylamines in the presence of [(dippe)Ni(μ-H)]2 (dippe = 1,2-bis-(diisopropylphosphino)-ethane) using ethanol as a solvent at 180 °C to give the corresponding saturated carbonyl compounds; here hydrogenation of the CC bond was preferred over the CO bond. Under the same reaction conditions but using an excess of benzylamine, a tandem process is then favoured, starting also with the reduction of the CC bond followed by a nucleophilic addition of the primary amine to yield valuable saturated imines with good to excellent yields (62%-91%).
- Castellanos-Blanco, Nahury,Flores-Alamo, Marcos,García, Juventino J.
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p. 15653 - 15663
(2015/09/07)
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- Anti-neoplastic activity of 1,3-diaza-2-functionalized-adamantan-6-one compounds against melanoma cells
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Four series of 1,3-diaza-2-functionalized-adamantan-6-one derivatives, bearing at the 2 position SO, SO2, POCl and PO2H functional groups, were synthesized via a key quadruple Mannich reaction, followed by transformation of an aminal functionality into th
- Sharabi-Ronen, Yifat,Levinger, Shlomo,Lellouche, Miri Ben-Dahan,Albeck, Amnon
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- Structural and spatial considerations in the N,N′-diacyl- and bis(alkoxycarbonyl)bispidinone series
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(Chemical Equation Presented) Diamidic and dicarbamic bispidinones show trans-cis isomerism, the relative population in solution of the cis form increasing with solvent polarity. The mutual proximity of the two amide functions in 4a has no impact on the b
- Levinger, Shlomo,Sharabi-Ronen, Yifat,Mainfeld, Alexander,Albeck, Amnon
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p. 7793 - 7796
(2008/12/22)
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