- Nickel(0)-Catalyzed Hydroalkylation of 1,3-Dienes with Simple Ketones
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We developed a highly regioselective addition of 1,3-dienes with simple ketones by nickel-hydride catalyst bearing DTBM-SegPhos ligand. A wide range of aromatic and aliphatic ketones directly coupled with 1,3-dienes, providing synthetically useful γ,δ-unsaturated ketones in high yield and regioselectivity. The asymmetric version of the reaction was also realized in high enantioselectivity by using novel chiral ligand DTBM-HO-BIPHEP. The utility of this hydroalkylation was demonstrated by facile product modification and enantioselective synthesis of (R)-flobufen.
- Cheng, Lei,Li, Ming-Ming,Xiao, Li-Jun,Xie, Jian-Hua,Zhou, Qi-Lin
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supporting information
p. 11627 - 11630
(2018/09/21)
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- Unprecedented alkylation of silicon enolates with alcohols via carbenium ion formations catalyzed by tin hydroxide-embedded montmorillonite
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The solid acid, tin hydroxide-embedded montmorillonite, catalyzes the unprecedented alkylation of various silicon enolates with primary, secondary and tertiary benzylic alcohols as well as secondary allylic alcohols. The acid catalysis of Sn-Mont was not only higher than that of the other ion-exchanged montmorillonites (M-Mont; M?=?H, Ti, Fe and Al), but also higher than that of the typical homogeneous acid catalysts such as BF3·OEt2, TMSOTf and TfOH.
- Tandiary, Michael Andreas,Asano, Masashi,Hattori, Taiki,Takehira, Satoshi,Masui, Yoichi,Onaka, Makoto
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p. 1925 - 1928
(2017/04/27)
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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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p. 11512 - 11514
(2016/01/15)
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- Cyclopentanone as a cation-stabilizing electron-pair donor in the calcium-catalyzed intermolecular carbohydroxylation of alkynes
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Although they have been used as reactivity-controlling additives in cationic polymerizations for decades, Lewis basic electron pair donor (ED) compounds were never used for the stabilization of cationic intermediates in transformations of small molecules. As such an ED, cyclopentanone proved highly efficient for the stabilization of allyl and vinyl cations in combination with our calcium-based catalyst system. Therefore, the first general transition-metal-free intermolecular carbohydroxylation of alkynes with allyl and propargyl alcohols was realized.
- Stopka, Tobias,Niggemann, Meike
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supporting information
p. 1437 - 1440
(2015/03/30)
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- Taming living carbocations in catalytic direct conjugate addition of simple alkenes to α,Enones
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A Lewis acid in the presence of an anionic phosphate ligand enables the addition of alkenes to α,enones. The ligand facilitates selective proton elimination by suppressing competing pathways, thus leading to vinylation adducts in high yields (up to 99%) for a broad range of substrates.
- Lv, Jian,Zhong, Xingren,Luo, Sanzhong
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supporting information
p. 8293 - 8296
(2014/07/08)
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- Trifluoroacetic anhydride - Catalyzed conjugate addition of boronic acids to α,β-unsaturated ketones
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The conjugate addition of boronic acids to α,β-unsaturated ketones catalyzed by acylating reagents has been explored. The results show that trifluoroacetic anhydride catalyzes the addition of vinylboronic acids under experimentally simple and metal-free conditions for a variety of substrates with good yields.
- Roscales, Silvia,Rincón, ángela,Buxaderas, Eduardo,Csák?, Aurelio G.
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experimental part
p. 4721 - 4724
(2012/09/08)
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- Catalytic decarboxylative alkylation of β-keto acids with sulfonamides via the cleavage of carbon-nitrogen and carbon-carbon bonds
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An efficient decarboxylative alkylation reaction of β-keto acids with N-benzylic or N-allylic sulfonamides has been developed, for the first time, through sequential cleavage of carbon-nitrogen and carbon-carbon bonds in the presence of 10 mol% of FeCl3.
- Yang, Cui-Feng,Wang, Jian-Yong,Tian, Shi-Kai
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supporting information; experimental part
p. 8343 - 8345
(2011/09/16)
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- Carbon-carbon bond formation by reactions of allylic alcohol with enoxysilane in the presence of Ir-complex
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Substitution of allylic alcohols to form a carbon-carbon bond is accomplished by a simple reaction of the allylic alcohol itself with an enoxysilane, catalyzed by [Ir(cod)(PPh3)2]X which is activated by H2 molecule. The anion part X of the complexes plays an important role to enhance the rate and product yields of the reactions. The efficacy of the catalyst increases with switching X in the order of PF6-4--.
- Matsuda, Isamu,Wakamatsu, Shogo,Komori, Ken-Ichi,Makino, Tatsuya,Itoh, Kenji
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p. 1043 - 1046
(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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- Molybdenum(II)- and tungsten(II)-catalyzed allylic substitution
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The molybdenum(II) complexes Mo(CO)5(OTf)2 (7a), [Mo(CO)4Br2]2 (8a), their tungsten(II) congeners 7b and 8b, and bimetallic complex Mo(CO)3(MeCN)2(SnCl3)Cl (9a) have been found to catalyze the C-C bond-forming allylic substitution with silyl enol ethers derived from β-dicarbonyls (e.g., 16 + 30 → 46) or from simple ketones (e.g., 16 + 32 → 50), aldehydes, and esters as nucleophiles under mild conditions (room temperature, 1-2 h). Methanol, as a prototype oxygen nucleophile, reacts in a similar fashion (e.g., 16 + MeOH → 43). Mechanistic and stereochemical experiments are indicative of Lewis-acid catalysis rather than a metal template-controlled process.
- Malkov, Andrei V.,Baxendale, Ian R.,Dvorak, Dalimil,Mansfield, Darren J.,Kocovsky, Pavel
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p. 2737 - 2750
(2007/10/03)
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- AN EFFECTIVE ACTIVATION OF ALLYL METHYL ETHERS BY A CATALYTIC AMOUNT OF TRITYL PERCHLORATE IN THE ALLYLATION OF SILYL ENOL ETHERS
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In the presence of a catalytic amount of trityl perchlorate, secondary and tertiary allyl methyl ethers smoothly react with silyl enol ethers to afford the corresponding γ,δ-unsaturated carbonyl compounds in good yields.By the combination of this reaction
- Mukaiyama, Teruaki,Nagaoka, Hitoshi,Ohshima, Masahiro,Murakami, Masahiro
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p. 1009 - 1012
(2007/10/02)
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