- Palladium-Catalyzed Synthesis of α-Methyl Ketones from Allylic Alcohols and Methanol
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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.
- Biswal, Priyabrata,Samser, Shaikh,Meher, Sushanta Kumar,Chandrasekhar, Vadapalli,Venkatasubbaiah, Krishnan
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supporting information
p. 413 - 419
(2021/11/01)
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- Manganese(I) catalyzed cross-coupling of secondary allylic alcohols and primary alcohols
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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.
- Pandia, Biplab Keshari,Pattanaik, Sandip,Gunanathan, Chidambaram
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- Substituent-Controlled Divergent Cascade Cycloaddition Reactions of Chalcones and Arylalkynols: Access to Spiroketals and Oxa-Bridged Fused Heterocycles
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Herein, we report substituent-controlled divergent cascade cycloaddition reactions of chalcones and arylalkynols in the presence of PtI2. Depending on the substituent on the chalcone, either spiroketals or oxa-bridged fused heterocycles could be obtained in the ranges of 86–97% and 87–95% yields under identical reaction conditions. Control experiments were carried out to elucidate the origin of the high chemoselectivity. These provide a method for the synthesis of a diverse array of structurally complex oxygen-containing heterocycles. (Figure presented.).
- Chang, Weixing,Kong, Jingyang,Li, Jing,Liu, Lingyan,Wang, Hongkai,Zeng, Tianlong
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supporting information
p. 4024 - 4032
(2021/07/12)
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- N-para-sulfonium salt substituted pyrazoline derivative, photocurable composition and preparation method
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The invention relates to an N-para-sulfonium salt substituted pyrazoline derivative shown as the following formula (I) in the specification, a photocurable composition, and a preparation method of theN-para-sulfonium salt substituted pyrazoline derivative shown as the following formula (I). The N-para-sulfonium salt substituted pyrazoline derivative shown as formula (I) has good absorption at a wavelength of 350nm or above, and compared with a 5-substituted sulfonium salt, the N-para-sulfonium salt substituted pyrazoline derivative has the advantages of simpler and more convenient molecule synthesis steps and reduced cost of raw materials, and is more suitable for industrial production and application.
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Paragraph 0239-0241; 0245-0246
(2020/07/21)
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- Photoredox β-thiol-α-carbonylation of enones accompanied by unexpected Csp2-C(CO) bond cleavage
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An olefinic difunctionalization method of enones was presented hereviaaerobic visible-light catalysis. A novel reactivity was showcased in conjunction with the selective Csp2-C(CO) bond activation of enones, which provided a convenient method for the preparation of various β-thiolated-α-functionalized compounds. Moreover, the preliminary investigation of the mechanism indicated that a β-peroxysulfide intermediate was formed under the promotion of visible light under an oxygen atmosphere, which finally induced the unexpected C-C bond cleavage.
- Du, Ding,Feng, Jie,Ma, Rui,Zhang, Beichen,Zhang, Kuili
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supporting information
p. 7549 - 7553
(2020/10/13)
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- Palladium-Catalyzed Carbonylative Synthesis of α-Branched Enones from Aryl Iodides and Arylallenes
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In this communication, an interesting carbonylation protocol for the preparation of α-branched enones has been established. Starting from readily available aryl iodides and allenes, with formic acid as the CO source and reductant, moderate to good yields of the desired enones were isolated. Although it is a carbonylation methodology, the use of a CO source can avoid the manipulation of CO gas directly. Notably, this procedure also presents the first example on carbonylative synthesis of α-branched enones.
- Geng, Hui-Qing,Hou, Chen-Yang,Wang, Le-Cheng,Wu, Xiao-Feng
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supporting information
p. 1160 - 1163
(2020/02/26)
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- Proton-Coupled Electron Transfer: Transition-Metal-Free Selective Reduction of Chalcones and Alkynes Using Xanthate/Formic Acid
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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.
- Prasanna, Ramanathan,Guha, Somraj,Sekar, Govindasamy
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supporting information
p. 2650 - 2653
(2019/04/17)
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- Iron-Catalyzed Tandem Three-Component Alkylation: Access to α-Methylated Substituted Ketones
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The borrowing hydrogen strategy has been applied in the synthesis of α-branched methylated ketones via a tandem three-component reaction catalyzed by a diaminocyclopentadienone iron tricarbonyl complex. Various alkyl and aromatic methyl ketones underwent dialkylation with various primary alcohols and methanol as alkylating agents in mild reaction conditions and good yields. Deuterium labeling experiments suggested that the benzylic alcohol was the hydrogen source in this tandem process.
- Bettoni, Léo,Seck, Charlotte,Mbaye, Mbaye DIagne,Gaillard, Sylvain,Renaud, Jean-Luc
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supporting information
p. 3057 - 3061
(2019/05/10)
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- Pd-catalyzed synthesis of α,β-unsaturated ketones by carbonylation of vinyl triflates and nonaflates
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A general and highly chemoselective Pd-catalyzed protocol for the synthesis of α,β-unsaturated ketones by carbonylation of vinyl triflates and nonaflates is presented. Applying the specific monophosphine ligand cataCXium A, the synthesis of various vinyl ketones as well as carbonylated natural product derivatives proceeds in good yields.
- Zhang, Shaoke,Neumann, Helfried,Beller, Matthias
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supporting information
p. 5938 - 5941
(2019/05/27)
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- Nickel-Catalyzed Hydrogen-Borrowing Strategy for α-Alkylation of Ketones with Alcohols: A New Route to Branched gem-Bis(alkyl) Ketones
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The α-alkylation of ketones using an earth-abundant and nonprecious NiBr2/L1 system is reported. This nickel-catalyzed reaction could be performed in gram scale and successfully applied in the synthesis of donepezil (Alzheimer's drug) and functionalization of steroid hormones and fatty acid derivatives. Synthesis of N-heterocycles, methylation of ketones, and one-pot double alkylation to bis-hetero aryl ketones using two different alcohols with a single catalyst broadens the scope of the catalytic protocol. Preliminary mechanistic studies using defined Ni-H species and deuterium-labeling experiments established the participation of the borrowing-hydrogen strategy.
- Das, Jagadish,Singh, Khushboo,Vellakkaran, Mari,Banerjee, Debasis
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supporting information
p. 5587 - 5591
(2018/09/25)
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- Scope and mechanism of the highly stereoselective metal-mediated domino aldol reactions of enolates with aldehydes
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A one-pot transformation, which involves the reaction of ketones with aldehydes in the presence of metal halides to furnish tetrahydro-2H-pyran-2,4-diols in a highly diastereoselective manner, is investigated thoroughly by experiments and computations. Th
- Cinar, M. Emin,Engelen, Bernward,Panth?fer, Martin,Deiseroth, Hans-J?rg,Schlirf, Jens,Schmittel, Michael
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supporting information
p. 813 - 824
(2016/07/06)
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- Synthesis of α,β-unsaturated ketones from alkynes and aldehydes over Hβ zeolite under solvent-free conditions
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A facile Hβ zeolite-catalyzed strategy has been successfully developed for the synthesis of α,β-unsaturated ketones from alkynes and aldehydes under solvent-free conditions. The reaction proceeds via tandem hydration/condensation of alkynes with aldehydes to afford a range of α,β-unsaturated carbonyls in good to excellent yields. This journal is.
- Mameda, Naresh,Peraka, Swamy,Kodumuri, Srujana,Chevella, Durgaiah,Banothu, Rammurthy,Amrutham, Vasu,Nama, Narender
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p. 58137 - 58141
(2016/07/07)
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- Dehydrogenation and oxidative coupling of alcohol and amines catalyzed by organosilicon-supported TiO2@PMHSIPN
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The catalytic dehydrogenation and tandem transformation of aromatic alcohols, including oxidative coupling of alcohols and amines, were achieved successfully using a catalytic amount of organosilicon-supported titania (TiO2@PMHSIPN), which enables the efficient synthesis of aromatic aldehydes, imines, and benzimidazoles in good to excellent yields. This journal is the Partner Organisations 2014.
- Wang, Hu,Zhang, Jin,Cui, Yu-Ming,Yang, Ke-Fang,Zheng, Zhan-Jiang,Xu, Li-Wen
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p. 34681 - 34686
(2014/11/08)
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- Iron(III)-catalyzed cyclization of alkynyl aldehyde acetals: Experimental and computational studies
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FeCl3·6H2O-and FeBr3-catalyzed Prins cyclization/halogenation of alkynyl aldehyde acetals has been realized with acetyl chloride or bromide as halogen source in dichloromethane to afford 2-(1-halobenzylidene or alkylidene)
- Xu, Tongyu,Yang, Qin,Li, Dongpo,Dong, Jinhua,Yu, Zhengkun,Li, Yuxue
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supporting information; experimental part
p. 9264 - 9272
(2010/10/03)
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- SYNTHESIS OF INDENES FROM PHENYLPROPANONES USING ALUMINA CATALYST
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1,3-Diphenylpropan-2-one undergoes dehydration over alumina at around 400 deg C to form 1,3-diphenylallene which cyclizes to 2-phenylindene.Since the parent ketone can be obtained under the reaction conditions from phenylacetic acid, the present reaction forms a one step syntheses of 2-phenylindene from phenylacetic acid. 3- and 4-methylphenylacetic acids also give the corresponding indenes. 1,3-Diphenylpropan-1-ones also give phenylindenes, presumably by a direct cyclodehydration reaction.
- Jayamani, M.,Pant, Nalin,Ananthan, S.,Narayanan, K.,Pillai, C. N.
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p. 4325 - 4332
(2007/10/02)
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- Synthesis of Selenacoumarins
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Selenacoumarin (2a) and 3-methylselenacoumarin (2b) have been synthesized by the cyclisation of selenophenyl cinnamate (1a) and selenophenyl 2-methylcinnamate (1b) respectively in the presence of AlCl3 in chlorobenzene.The compounds have been characterised by elemental analysis and spectral (IR, PMR and mass) data.
- Jayachandran, T.,Manimaran, T.,Ramakrishnan, V. T.
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p. 328 - 330
(2007/10/02)
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- PREPARATION OF 1-PHENYL-3-METHYLISOQUINOLINE AND ITS DERIVATIVES FROM OXIMES OF 3-ARYL-2-METHYL-1-PHENYL-2-PROPEN-1-ONES
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1-Phenyl-3-methylisoquinoline and its derivatives substituted in 5, 6 or 7 positions (4) have been obtained by cyclization reaction of N-α-methylstyrylbenzimidoyl chloride (3) produced by Beckmann rearrangement by appopriate oximes (2) in the presence of PCl5.
- Zielinski, Wojciech
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p. 2209 - 2215
(2007/10/02)
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