20795-51-1Relevant articles and documents
NOVEL METHOD FOR OXIDATION OF SECONDARY ALCOHOLS INTO KETONES WITH MOLECULAR OXIGEN BY USING COBALT(II) COMPLEX CATALYST
Yamada, Tohru,Mukaiyama, Teruaki
, p. 519 - 522 (1989)
The oxidation of secondary alcohols into the corresponding ketones using a catalytic amount of cobalt(II) complex under an oxygen atmosphere is described.The effect of additives shows that Molecular Sieves is effective to improve the yield of ketones.
Sulfonium ion-promoted traceless Schmidt reaction of alkyl azides
Ardiansah, Bayu,Kakiuchi, Kiyomi,Morimoto, Tsumoru,Tanimoto, Hiroki,Tomohiro, Takenori
, p. 8738 - 8741 (2021/09/08)
Schmidt reaction by sulfonium ions is described. General primary, secondary, and tertiary alkyl azides were converted to the corresponding carbonyl or imine compounds without any trace of the activators. This bond scission reaction through 1,2-migration of C-H and C-C bonds was accessible to the one-pot substitution reaction.
Chemoselective reduction of ?,￠-unsaturated carbonyl and carboxylic compounds by hydrogen iodide
Matsumoto, Shoji,Marumoto, Hayato,Akazome, Motohiro,Otani, Yasuhiko,Kaiho, Tatsuo
, p. 590 - 599 (2021/03/29)
The selective reduction of ?,￠-unsaturated carbonyl compounds was achieved to produce saturated carbonyl compounds with aqueous HI solution. The introduction of an aryl group at an ? or ￠ position efficiently facilitated the reduction with good yield. The reaction was applicable to compounds bearing carboxylic acids and halogen atoms. Through the investigation of the reaction mechanism, it was found that Michael-type addition of iodide occurred to produce ￠-iodo compounds followed by the reduction of C-I bond via anionic and radical paths.
Scope and Mechanism of the Redox-Active 1,2-Benzoquinone Enabled Ruthenium-Catalyzed Deaminative α-Alkylation of Ketones with Amines
Kirinde Arachchige, Pandula T.,Handunneththige, Suhashini,Talipov, Marat R.,Kalutharage, Nishantha,Yi, Chae S.
, p. 13962 - 13972 (2021/11/20)
The catalytic system formed in situ from the reaction of a cationic Ru-H complex with 3,4,5,6-tetrachloro-1,2-benzoquinone was found to mediate a regioselective deaminative coupling reaction of ketones with amines to form the α-alkylated ketone products. Both benzylic and aliphatic primary amines were found to be suitable substrates for the coupling reaction with ketones in forming the α-alkylated ketone products. The coupling reaction of PhCOCD3 with 4-methoxybenzylamine showed an extensive H/D exchange on both α-CH2 (41% D) and β-CH2 (21%) positions on the alkylation product. The Hammett plot obtained from the reaction of acetophenone with para-substituted benzylamines p-X-C6H4CH2NH2 (X = OMe, Me, H, F, Cl, CF3) showed a strong promotional effect by the amine substrates with electron-releasing groups (ρ = -0.49 ± 0.1). The most significant carbon isotope effect was observed on the α-carbon of the alkylation product (Cα = 1.020) from the coupling reaction of acetophenone with 4-methoxybenzylamine. The kinetics of the alkylation reaction from an isolated imine substrate led to the empirical rate law: rate = k[Ru][imine]. A catalytically active Ru-catecholate complex was synthesized from the reaction of the cationic Ru-H complex with 3,5-di-tert-butyl-1,2-benzoquinone and PCy3. The DFT computational study was performed on the alkylation reaction, which revealed a stepwise mechanism of the [1,3]-carbon migration step via the formation of a Ru(IV)-alkyl species with a moderate energy of activation (ΔG? = 32-42 kcal/mol). A plausible mechanism of the catalytic alkylation reaction via an intramolecular [1,3]-alkyl migration of an Ru-enamine intermediate has been compiled on the basis of these experimental and computational data.
Cobalt-Catalyzed Asymmetric 1,4-Reduction of β,β-Dialkyl α,β-Unsaturated Esters with PMHS
Lu, Dongpo,Lu, Peng,Lu, Zhan
supporting information, p. 4861 - 4864 (2021/09/22)
A cobalt-catalyzed asymmetric reduction of β,β-dialkyl α,β-unsaturated esters with polymethylhydrosiloxane (PMHS) was reported to deliver the corresponding esters containing a chiral trialkyl carbon center at β-position with up to 97 % yield and 98 % ee. The chiral tridentate ligand oxazoline iminopyridine (OIP) could perform well for the asymmetric reduction instead of chiral bidentate ligands. This operationally simple protocol shows a broad scope of substrates using one equivalent of readily available PMHS as a cheap and easy-to-handle reductive reagent.
Visible-Light-Promoted Catalytic Ring-Opening Isomerization of 1,2-Disubstituted Cyclopropanols to Linear Ketones
Laktsevich-Iskryk, Marharyta V.,Varabyeva, Nastassia A.,Kazlova, Volha V.,Zhabinskii, Vladimir N.,Khripach, Vladimir A.,Hurski, Alaksiej L.
supporting information, p. 2431 - 2434 (2020/04/20)
Isomerization to linear ketones is a valuable transformation of 1,2-disubstituted cyclopropanols proceeding through radical intermediates. Despite simplicity of this reaction, the known protocol required stoichiometric amounts of both an oxidant and a reducing agent. In this article, we report a catalytic isomerization of 1,2-disubstituted cyclopropanols to linear ketones enabled by the photoredox catalytic system consisting of an acridinium photocatalyst and diphenyl disulfide under irradiation with blue LEDs.
Ligand-Controlled Regiodivergent Silylation of Allylic Alcohols by Ni/Cu Catalysis for the Synthesis of Functionalized Allylsilanes
Gan, Yi,Xu, Wei,Liu, Yuanhong
supporting information, p. 9652 - 9657 (2019/11/28)
The first Ni/Cu-catalyzed regiodivergent synthesis of allylsilanes directly from allylic alcohols through modulating the steric and electronic properties of the ligands on the nickel catalyst has been developed. Good yields and excellent selectivity were obtained regardless of whether linear or α-branched allylic alcohols were utilized. Mechanistic studies indicate that an allyloxyboronate species is formed during the reaction, which likely serves as an activated intermediate toward the oxidative addition of the C(allyl)-O bond.
Palladium-catalyzed room temperature acylative cross-coupling of activated amides with trialkylboranes
Shi, Weijia,Zou, Gang
, (2018/10/02)
A highly efficient acylative cross-coupling of trialkylboranes with activated amides has been effected at room temperature to give the corresponding alkyl ketones in good to excellent yields by using 1,3-bis(2,6-diisopropyl)phenylimidazolylidene and 3-chloropyridine co-supported palladium chloride, the PEPPSI catalyst, in the presence of K2CO3 in methyl tert-butyl ether. The scope and limitations of the protocol were investigated, showing good tolerance of acyl, cyano, and ester functional groups in the amide counterpart while halo group competed via the classical Suzuki coupling. The trialkylboranes generated in situ by hydroboration of olefins with BH3 or 9-BBN performed similarly to those separately prepared, making this protocol more practical.
Chelation-Assisted C-H and C-C Bond Activation of Allylic Alcohols by a Rh(I) Catalyst under Microwave Irradiation
Lee, Chang-Hee,Jun, Chul-Ho
, p. 736 - 741 (2017/11/27)
Chelation-assisted Rh(I)-catalyzed ketone synthesis from allylic alcohols and alkenes through C-H and C-C bond activations under microwave irradiation was developed. Aldimine is formed via olefin isomerization of allyl alcohol under Rh(I) catalysis and condensation with 2-amino-3-picoline, followed by continuous C-H and C-C bond activations to produce a dialkyl ketone. The addition of piperidine accelerates the reaction rate by promoting aldimine formation under microwave conditions.
Dinuclear Pathways for the Activation of Strained Three-Membered Rings
Rounds, Heather R.,Zeller, Matthias,Uyeda, Christopher
, p. 545 - 550 (2018/03/08)
Dinuclear, strain-induced ring-opening reactions of vinylaziridines and vinylcyclopropanes are described. The previously reported [NDI]Ni2(C6H6) complex (NDI = naphthyridine-diimine) reacts with N-tosyl-2-vinylaziridine via C-N oxidative addition to generate a dinickel metallacyclic product. On the basis of this stoichiometric reactivity, the [NDI]Ni2(C6H6) complex is shown to be a highly active catalyst for the rearrangement of vinylcyclopropane to cyclopentene. Notably, 2-phenyl-1-vinylcyclopropane undergoes regioselective activation at the less hindered C-C bond in contrast to the noncatalytic thermal rearrangement. DFT calculations provide insight into the ability of the Ni-Ni bond to stabilize key intermediates and transition states along the catalytic pathway.
