- A phosphine-free iron complex-catalyzed synthesis of cycloalkanes: Via the borrowing hydrogen strategy
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Herein we report a diaminocyclopentadienone iron tricarbonyl complex catalyzed synthesis of substituted cyclopentane, cyclohexane and cycloheptane compounds using the borrowing hydrogen strategy in the presence of various substituted primary and secondary 1,n diols as alkylating reagents. Deuterium labeling experiments confirm that the diols were the hydride source in this cascade process. This journal is
- Bettoni, Léo,Gaillard, Sylvain,Renaud, Jean-Luc
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supporting information
p. 12909 - 12912
(2020/11/07)
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- Direct Synthesis of Cycloalkanes from Diols and Secondary Alcohols or Ketones Using a Homogeneous Manganese Catalyst
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A method for the synthesis of substituted cycloalkanes was developed using diols and secondary alcohols or ketones via a cascade hydrogen borrowing sequence. A non-noble and air-stable manganese catalyst (2 mol %) was used to perform this transformation. Various substituted 1,5-pentanediols (3-4 equiv) and substituted secondary alcohols (1 equiv) were investigated to prepare a collection of substituted cyclohexanes in a diastereoselective fashion. Similarly, cyclopentane, cyclohexane, and cycloheptane rings were constructed from substituted 1,4-butanediol, 1,5-pentanediol, and 1,6-hexanediol, and sterically hindered ketones following a (4 + 1), (5 + 1), and (6 + 1) strategy, respectively. This reaction provides an atom economic methodology to construct two C-C bonds at a single carbon center generating high-value cycloalkanes from readily available alcohols as feedstock using an earth-abundant metal catalyst.
- Kaithal, Akash,Gracia, Lisa-Lou,Camp, Clément,Quadrelli, Elsje Alessandra,Leitner, Walter
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supporting information
(2019/11/21)
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- Stereoselective synthesis of alicyclic ketones: A hydrogen borrowing approach
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A highly diastereoselective annulation strategy for the synthesis of alicyclic ketones from diols and pentamethylacetophenone is described. This process is mediated by a commercially available iridium(III) catalyst, and provides efficient access to a wide range of cyclopentane and cyclohexane products with high levels of stereoselectivity. The origins of diastereoselectivity in the annulation reaction have been explored by a series of control experiments, which provides an explanation for how each stereocentre around the newly forged ring is controlled.
- Armstrong, Roly J.,Akhtar, Wasim M.,Frost, James R.,Christensen, Kirsten E.,Stevenson, Neil G.,Donohoe, Timothy J.
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supporting information
(2019/11/13)
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- Photochemical Homologation for the Preparation of Aliphatic Aldehydes in Flow
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Cheap and readily available aqueous formaldehyde was used as a formylating reagent in a homologation reaction with nonstabilized diazo compounds, enabled by UV photolysis of bench-stable oxadiazolines in a flow photoreactor. Various aliphatic aldehydes were synthesized along with the corresponding derivatized alcohols and benzimidazoles. No transition-metal catalyst or additive was required to affect the reaction, which proceeded at room temperature in 80 min.
- Chen, Yiding,Leonardi, Marco,Dingwall, Paul,Labes, Ricardo,Pasau, Patrick,Blakemore, David C.,Ley, Steven V.
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p. 15558 - 15568
(2019/01/04)
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- Stereoselective Synthesis of Cyclohexanes via an Iridium Catalyzed (5 + 1) Annulation Strategy
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An iridium catalyzed method for the synthesis of functionalized cyclohexanes from methyl ketones and 1,5-diols is described. This process operates by two sequential hydrogen borrowing reactions, providing direct access to multisubstituted cyclic products with high levels of stereocontrol. This methodology represents a novel (5 + 1) strategy for the stereoselective construction of the cyclohexane core.
- Akhtar, Wasim M.,Armstrong, Roly J.,Frost, James R.,Stevenson, Neil G.,Donohoe, Timothy J.
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supporting information
p. 11916 - 11920
(2018/09/27)
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- METHOD FOR THE PRODUCTION OF 1.6-HEXANEDIOL
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The invention relates to a method for producing 1,6-hexanediol having a purity of > 99.5 wt. % by catalytic dimerisation of acrylic acid esters, catalytic hydrogenation of the thus obtained hexene diacidic diester in order to form 1.6-hexanediol. Said method consists in: a) dimerising C1- C8-acrylic acid esters in the presence of at least one rhodium compound in order to form mixtures predominantly of 2- and 3-hexene diacdic diesters, b) hydrating the obtained dimerisation discharge in the presence of chrome-free catalysts containing mainly copper as a hydrogenation component and c) purifying the thus obtained raw 1.6-hexanediol by fractionating distillation.
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- Dod-S-Me and methyl 6-morpholinohexyl sulfide (MMS) as new odorless borane carriers
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Odorless Dod-S-Me (1) and MMS (3) are developed as efficient borane carriers. The yields of hydroborations and reductions with borane complex 2 of 1 are very high and the recovery of 1 after the reaction is quantitative. The borane complexes 4 and 5 of 3 are also useful. In the latter case chromatographic separation is unnecessary when excess oxidizing agent (alkaline H2O2) is used after hydroboration.
- Patra, Pranab K.,Nishide, Kiyoharu,Fuji, Kaoru,Node, Manabu
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p. 1003 - 1006
(2007/10/03)
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- Lipase-catalyzed monoprotection of 1,4-diols in an organic solvent using vinyl benzoate as acyl transfer agent
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Lipase from Mucor miehei (MML) has been selected as the most suitable enzyme to catalyze the efficient monobenzoylation of 1,4-diols using vinyl benzoate as acyl transfer reagent in tert-butyl methyl ether. The regioselectivity of the monobenzoylation of
- Ciuffreda, Pierangela,Casati, Silvana,Santaniello, Enzo
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p. 3663 - 3665
(2007/10/03)
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- Process for reductive hydrolysis of nitriles
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This invention concerns processes for the reductive hydrolysis of nitriles to alcohols utilizing as a catalyst a transition metal complex of the formula MHZ(CO)Ln (PR3)2 wherein: M is a transition metal selected from the group consisting of: Fe, Ru and Os; Z is an anionic ligand; L is a neutral ligand; n is 0 or 1; and PR3 is a phosphine ligand.
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- The Stereochemistry of Organometallic Compounds. XXXVIII. Regio- and Stereo-control in the Rhodium-Catalysed Hydroformylation of Some Alkenyl Phosphites
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Excellent regiocontrol is achieved in the rhodium-catalysed hydroformylation of some alkenyl phosphites, and good stereocontrol is obtained in the hydroformylation of some cyclohexenyl phosphites.The stereochemical results have implications for the mechanism of these rhodium-catalysed reactions.
- Jackson, W. Roy,Moffat, Mark R.,Perlmutter, Patrick,Tasdelen, E. Elizabeth
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p. 823 - 834
(2007/10/02)
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- TRANSFORMATION OF ALLYLIC EPOXIDES TO TETRAHYDROFURFURYL ALCOHOLS VIA HYDROBORATION
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The allylic epoxides (1)-(4) were transformed to the tetrahydrofurfuryl alcohols (17)-(20), respectively.The formation of (6) and (10) in the hydroboration-oxidation of (4) is interpreted.The monohydroboration-oxidation of (13) and (14) gave (15) and (16), respectively.
- Zaidlewicz, Marek,Sarnowski, Ryszard
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p. 281 - 284
(2007/10/02)
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