- Rhodium-Catalyzed Branched and Enantioselective Direct α-Allylic Alkylation of Simple Ketones with Alkynes
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Herein, we report the first direct branched-selective α-allylic alkylation of simple ketones with alkynes under rhodium and secondary amine cooperative catalysis. Through a rhodium-hydride-catalyzed allylic substitution pathway, a series of valuable γ,δ-unsaturated ketones are obtained with excellent regioselectivity in an atom-economic and byproduct-free manner. With a chiral BIPHEP ligand, high enantioselectivity has been achieved for this transformation.
- Ma, Mingliang,Xie, Liyu,Xing, Dong,Yang, Haijian
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supporting information
(2020/03/10)
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- Gamma-alkenyl ketone and synthesis method thereof
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The invention discloses gamma-alkenyl ketone and a preparation method thereof. Simple cyclic ketones or non-cyclic methyl ketones such as cyclopentanone and 1-phenyl-1-propyne are used as raw materials, and a target product is obtained with high yield, high regioselectivity and high enantioselectivity in the presence of an organic solvent, a catalyst, an additive and a ligand. The gamma-alkenyl ketone has the advantages of atom economy, high regioselectivity, high enantioselectivity and the like, and efficient conversion from cheap basic organic chemicals to high-added-value gamma-alkenyl ketone can be realized. The synthesized gamma-alkenyl ketone is a potential synthesis intermediate, and has potential application prospects in fine chemical synthesis and drug intermediate synthesis.
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Paragraph 0100-0102
(2020/08/27)
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- Regioselective Rhodium-Catalyzed Addition of β-Keto Esters, β-Keto Amides, and 1,3-Diketones to Internal Alkynes
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The first rhodium-catalyzed regioselective addition of 1,3-dicarbonyl compounds, including β-keto esters, β-keto amides, and 1,3-diketones, to internal alkynes furnishes branched allylic compounds. By applying RhI/DPEphos/TFA as the catalytic system, aliphatic as well as aromatic internal methyl-substituted alkynes act as suitable substrates to yield valuable branched α-allylated 1,3-dicarbonyl compounds regioselectively in good to excellent yields. A simple basic saponification–decarboxylation procedure provides access to valuable γ,δ-unsaturated ketones. The reaction shows a broad functional-group tolerance, and numerous structural variations on both reaction partners highlight the synthetic potential and flexibility of this method.
- Beck, Thorsten M.,Breit, Bernhard
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supporting information
p. 5839 - 5844
(2016/12/18)
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- An Organocatalytic Cope Rearrangement
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The first example of an organocatalytic Cope rearrangement is reported. Acyclic and cyclic acyl hydrazides catalyze the rearrangement of 1,5-hexadiene-2-carboxaldehydes via iminium ion formation. A correlation between ring size and catalyst activity was observed for the cyclic hydrazides, with seven- and eight-membered-ring catalysts being the most active. Diazepane carboxylate 5 c (10 mol %) catalyzed the rearrangement of a range of dienes at room temperature in acetonitrile using triflic acid as a co-catalyst. Preliminary proof of principle for asymmetric catalysis was provided by rearrangement of 3,3-dimethyl-7-phenyl-1,5-heptadiene-2-carboxaldehyde in the presence of a novel 7-substituted diazepane carboxylate.
- Kaldre, Dainis,Gleason, James L.
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supporting information
p. 11557 - 11561
(2016/10/24)
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- Rhodium-catalyzed chemo- and regioselective decarboxylative addition of β-ketoacids to alkynes
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A highly efficient rhodium-catalyzed chemo- and regioselective addition of β-ketoacids to alkynes is reported. Applying a Rh(i)/(S,S)-DIOP catalyst system, γ,δ-unsaturated ketones were prepared with exclusively branched selectivity under mild conditions. This demonstrates that readily available alkynes can be an alternative entry to allyl electrophiles in transition-metal catalyzed allylic alkylation reactions.
- Li, Changkun,Grugel, Christian P.,Breit, Bernhard
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supporting information
p. 5840 - 5843
(2016/05/19)
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- Iridium-catalyzed regioselective decarboxylative allylation of β-ketoacids: Efficient construction of γ,δ-unsaturated ketones
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A highly regioselective protocol for the direct synthesis of γ,δ-unsaturated ketones from β-ketoacids and allylic alcohols was proposed and accomplished relying on the combination of [Ir(cod)Cl]2 and 10-camphorsulfonic acid via decarboxylative allylation.
- Chen, Shu-Jie,Lu, Guo-Ping,Cai, Chun
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supporting information
p. 11512 - 11514
(2016/01/15)
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- Iridium-catalyzed enantioselective allyl-alkene coupling
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The direct Ir-catalyzed cross-coupling between branched, racemic allylic alcohols and simple olefins is described. This transformation is catalyzed by an Ir-(P,olefin) complex and proceeds with high site selectivity and excellent enantioselectivity. The m
- Hamilton, James Y.,Sarlah, David,Carreira, Erick M.
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supporting information
p. 3006 - 3009
(2014/03/21)
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- Rhodium-catalyzed chemo- and regioselective decarboxylative addition of β-ketoacids to allenes: Efficient construction of tertiary and quaternary carbon centers
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A rhodium-catalyzed chemo- and regioselective intermolecular decarboxylative addition of β-ketoacids to terminal allenes is reported. Using a Rh(I)/DPPF system, tertiary and quaternary carbon centers were formed with exclusively branched selectivity under mild conditions. Preliminary mechanism studies support that the carbon-carbon bond formation precedes the decarboxylation and the reaction occurs in an outer-sphere mechanism.
- Li, Changkun,Breit, Bernhard
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supporting information
p. 862 - 865
(2014/02/14)
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- Catalytic enantioselective allyl-allyl cross-coupling with a borylated allylboronate
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Catalytic enantioselective allyl-allyl cross-coupling of a borylated allylboronate reagent gives versatile borylated chiral 1,5-hexadienes. These compounds may be manipulated in a number of useful ways to give functionalized chiral building blocks for asymmetric synthesis.
- Le, Hai,Kyne, Robert E.,Brozek, Laura A.,Morken, James P.
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supporting information
p. 1432 - 1435
(2013/07/05)
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- Chemo- and regioselectivity-tunable Pd-catalyzed allylic alkylation of imines
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α-Carbanions of cyclic and acyclic imines have been successfully applied as nucleophiles in the Pd-catalyzed allylic alkylation reaction. Tuning of chemo- and regioselectivity has been realized by using t-BuOK/THF and LDA/toluene to give branched and line
- Chen, Jian-Ping,Peng, Qian,Lei, Bai-Lin,Hou, Xue-Long,Wu, Yun-Dong
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supporting information; experimental part
p. 14180 - 14183
(2011/10/13)
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- Highly regioselective [3,3] rearrangement of aliphatic allyl vinyl ethers catalyzed by a metalloporphyrin complex, Cr(TPP)Cl
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The Claisen rearrangement of simple aliphatic allyl vinyl ethers catalyzed by a metalloporphyrin, Cr(TPP)Cl, is described. The porphyrin-based Lewis acid catalyst can effectively accelerate the rearrangement via a concerted [3,3] pathway with a minimal degree of bond ionization of the substrates, providing the corresponding Claisen products in moderate to high yields and almost perfect regioselectivity at low catalyst loading.
- Takanami, Toshikatsu,Hayashi, Mikiko,Iso, Kazuhiro,Nakamoto, Hirose,Suda, Kohji
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p. 9467 - 9474
(2007/10/03)
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- Ruthenium-catalyzed decarboxylative allylation of nonstabilized ketone enolates
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(Matrix Presented) Bipyridyl(pentamethylcyclopentadienyl)ruthenium chloride is an efficient catalyst for the formal [3,3] rearrangement of allyl β-ketoesters. The mechanism of the transformation involves formation of π-allyl ruthenium intermediates, which
- Burger, Erin C.,Tunge, Jon A.
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p. 2603 - 2605
(2007/10/03)
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- Rhodium-catalyzed substitution of allylic carbonates with enoxysilanes
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Substitution at the allylic position proceeds smoothly in rhodium-catalyzed reactions of allyl carbonates with enoxysilanes under almost neutral conditions to give γ,δ-unsaturated ketones in good to excellent yields. (C) 2000 Elsevier Science Ltd.
- Muraoka,Matsuda,Itoh
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p. 8807 - 8811
(2007/10/03)
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