4842-43-7Relevant academic research and scientific papers
Stereocontrol of Paterno-Buchi photocycloadditions
Fleming, Steven A.,Gao, J. Jerry
, p. 5407 - 5410 (1997)
Diphenyloxetane was synthesized from photocycloaddition of benzaldehyde and styrene. The oxetane products, 2,3 trans and 2,3 cis isomers, were observed in a 3:1 ratio. Irradiation of 1-phenylpropene and trimethylsilyl cinnamyl ether under the same conditions also gave oxetanes. The silyl group resulted in high stereoselectivity for the oxetane formation.
Palladium-Catalyzed Synthesis of α-Methyl Ketones from Allylic Alcohols and Methanol
Biswal, Priyabrata,Samser, Shaikh,Meher, Sushanta Kumar,Chandrasekhar, Vadapalli,Venkatasubbaiah, Krishnan
, p. 413 - 419 (2021/11/01)
One-pot synthesis of α-methyl ketones starting from 1,3-diaryl propenols or 1-aryl propenols and methanol as a C1 source is demonstrated. This one-pot isomerization-methylation is catalyzed by commercially available Pd(OAc)2 with H2O as the only by-product. Mechanistic studies and deuterium labelling experiments indicate the involvement of isomerization of allyl alcohol followed by methylation through a hydrogen-borrowing pathway in these isomerization-methylation reactions.
Manganese(I) catalyzed cross-coupling of secondary allylic alcohols and primary alcohols
Pandia, Biplab Keshari,Pattanaik, Sandip,Gunanathan, Chidambaram
, (2021/11/01)
Cross-coupling of alcohols to value-added products by using sustainable catalytic reactions has gained attention in recent years. Isomerization of secondary allylic alcohol to the corresponding enolizable ketone is an atom economical and known transformation. Herein, a selective cross-coupling of secondary allylic alcohol and primary alcohol is reported to afford the corresponding α-alkenyl or alkylation products. These catalytic protocols proceed via acceptorless dehydrogenative coupling (ADC) or borrowing hydrogen (BH) strategies, which liberates water and/or hydrogen as the only byproducts. Highly abundant manganese-based pincer catalysts catalyze the reactions.
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.
Neutral-eosin Y-catalyzed regioselective hydroacylation of aryl alkenes under visible-light irradiation
Liu, Haiwang,Xue, Fei,Wang, Mu,Tang, Xinxin,Wu, Jie
supporting information, p. 406 - 410 (2020/12/30)
Styrene derivatives were hydroacylated with exclusive anti-Markovnikov selectivity by using neutral eosin Y as a direct hydrogen-atom-transfer (HAT) catalyst under visible-light irradiation. Aldehydes and styrenes with various substituents were tolerated (>20 examples), giving the corresponding products in moderate to high yields. The key acyl radical intermediate was generated from a direct HAT process induced by photoexcited eosin Y. Subsequent addition to styrenes and a reverse HAT process generated the ketone products.
Application of 4, 6-dimethyl-2-mercaptopyrimidine bivalent nickel complex in preparation of [alpha]-alkyl ketone
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Paragraph 0038-0040, (2021/04/07)
The invention relates to the field of metal organic chemistry, in particular to application of a 4, 6-dimethyl-2-mercaptopyrimidine bivalent nickel complex in preparation of [alpha]-alkyl ketone, which takes a 4, 6-dimethyl-2-mercaptopyrimidine nickel (II) compound as a catalyst and realizes selective preparation of [alpha]-alkyl ketone through cross-coupling reaction of secondary alcohol and primary alcohol by regulating and controlling reaction conditions. The coupling reaction is carried out in anhydrous toluene in the presence of alkali under the protection of inert gas. The application has the advantages of mild reaction system conditions and wide substrate applicability, and effectively avoids the use of organic phosphine ligands and noble metals.
Visible-Light-Promoted Photocatalyst-Free Hydroacylation and Diacylation of Alkenes Tuned by NiCl2·DME
Zhao, Xinxin,Li, Bing,Xia, Wujiong
, p. 1056 - 1061 (2020/02/15)
Herein, we describe a visible light-promoted hydroacylation strategy that facilitates the preparation of ketones from alkenes and 4-acyl-1,4-dihydropyridines via an acyl radical addition and hydrogen atom transfer pathway under photocatalyst-free conditions. The efficiency was highlighted by wide substrate scope, good to high yields, successful scale-up experiments, and expedient preparation of highly functionalized ketone derivatives. In addition, this protocol allows for the synthesis of 1,4-dicarbonyl compounds through alkene diacylation in the presence of NiCl2·DME.
Electrochemical 1,4-reduction of α,β-unsaturated ketones with methanol and ammonium chloride as hydrogen sources
Huang, Binbin,Li, Yanan,Yang, Chao,Xia, Wujiong
supporting information, p. 6731 - 6734 (2019/06/17)
A sustainable, chemoselective 1,4-reduction of α,β-unsaturated ketones by means of an electrochemical method is presented, wherein the extremely inexpensive ammonium chloride (NH4Cl) is applied as the only additive. The reaction proceeds smoothly in the air at ambient temperature. Mechanistic studies reveal that both NH4Cl and solvent methanol work as hydrogen donors.
Proton-Coupled Electron Transfer: Transition-Metal-Free Selective Reduction of Chalcones and Alkynes Using Xanthate/Formic Acid
Prasanna, Ramanathan,Guha, Somraj,Sekar, Govindasamy
supporting information, p. 2650 - 2653 (2019/04/17)
Highly chemoselective reduction of α,β-unsaturated ketones to saturated ketones and stereoselective reduction of alkynes to (E)-alkenes has been developed under a transition-metal-free condition using a xanthate/formic acid mixture through proton-coupled electron transfer (PCET). Mechanistic experiments and DFT calculations support the possibility of a concerted proton electron-transfer (CPET) pathway. This Birch-type reduction demonstrates that a small nucleophilic organic molecule can be used as a single electron-transfer (SET) reducing agent with a proper proton source.
Reaction condition controlled nickel(ii)-catalyzed C-C cross-coupling of alcohols
Zhang, Meng-Juan,Li, Hong-Xi,Young, David J.,Li, Hai-Yan,Lang, Jian-Ping
supporting information, p. 3567 - 3574 (2019/04/14)
The challenge in the C-C cross-coupling of secondary and primary alcohols using acceptorless dehydrogenation coupling (ADC) is the difficulty in accurately controlling product selectivities. Herein, we report a controlled approach to a diverse range of β-alkylated secondary alcohols, α-alkylated ketones and α,β-unsaturated ketones using the ADC methodology employing a Ni(ii) 4,6-dimethylpyrimidine-2-thiolate cluster catalyst under different reaction conditions. This catalyst could tolerate a wide range of substrates and exhibited a high activity for the annulation reaction of secondary alcohols with 2-aminobenzyl alcohols to yield quinolines. This work is an example of precise chemoselectivity control by careful choice of reaction conditions.
