62085-78-3Relevant academic research and scientific papers
Nickel-Catalyzed Selective Synthesis of α-Alkylated Ketones via Dehydrogenative Cross-Coupling of Primary and Secondary Alcohols
Bains, Amreen K,Biswas, Ayanangshu,Adhikari, Debashis
supporting information, p. 47 - 52 (2021/10/14)
Herein, we describe an isolable, air-stable, homogeneous, nickel catalyst that performs dehydrogenative cross-coupling reaction between secondary and primary alcohols to result α-alkylated ketone products selectively. The sequence of steps involve in this one-pot reaction is dehydrogenation of both alcohols, condensation between the ketone and the aldehyde, and hydrogenation of the in situ-generated α,β-unsaturated ketone. Preliminary mechanistic investigation hints a radical mechanism following borrowing hydrogen reaction. (Figure presented.).
Asymmetric Hydrogenation of Racemic Allylic Alcohols via an Isomerization-Dynamic Kinetic Resolution Cascade
Guo, Xin,Niu, Saisai,Sun, Huaming,Tang, Weijun,Wang, Chao,Wang, Kun,Xiao, Jianliang,Xue, Dong
, (2022/02/05)
Prochiral racemic allylic alcohols are converted to enantioenriched chiral alcohols bearing adjacent stereocenters catalyzed by a diamine diphosphine Ru complex in the presence of tBuOK. The protocol features a broad substrate scope (56 examples) and high
NNN pincer Ru(II)-complex-catalyzed α-alkylation of ketones with alcohols
Cao, Xiao-Niu,Wan, Xiao-Min,Yang, Fa-Liu,Li, Ke,Hao, Xin-Qi,Shao, Tian,Zhu, Xinju,Song, Mao-Ping
, p. 3657 - 3668 (2018/04/14)
A series of novel ruthenium(II) complexes supported by a symmetrical NNN ligand were prepared and fully characterized. These complexes exhibited good performance in transfer hydrogenation to form new C-C bonds using alcohols as the alkylating agents, generating water as the only byproduct. A broad range of substrates, including (hetero)aryl- or alkyl-ketones and alcohols, were well tolerated under the optimized conditions. Notably, α-substituted methylene ketones were also investigated, which afforded α-branched steric hindrance products. A potential application of α-alkylation of methylene acetone to synthesize donepezil was demonstrated, which provided the desired product in 83% yield. Finally, this catalytic system could be applied to a one-pot double alkylation procedure with sequential addition of two different alcohols. The current protocol is featured with several characteristics, including a broad substrate scope, low catalyst (0.50 mol %) loadings, and environmental benignity.
Isolation and Characterization of Regioisomers of Pyrazole-Based Palladacycles and Their Use in α-Alkylation of Ketones Using Alcohols
Mamidala, Ramesh,Samser, Shaikh,Sharma, Nishant,Lourderaj, Upakarasamy,Venkatasubbaiah, Krishnan
supporting information, p. 3343 - 3351 (2017/09/18)
Regioisomers of 3,5-diphenyl-1-(4-(trifluoromethyl)phenyl)-1H-pyrazole-based palladacycles (1 and 2) were synthesized by the aromatic C-H bond activation of N/3-aryl ring. The application of these regioisomers as catalysts to enable the formation of α-alkylated ketones or quinolines with alcohols using a hydrogen borrowing process is evaluated. Experimental results reveal that palladacycle 2 is superior over palladacycle 1 to catalyze the reaction under similar reaction conditions. The reaction mechanisms for the palladacycles 1 and 2 catalyzed α-alkylation of acetophenone were studied using density functional theoretical (DFT) methods. The DFT studies indicate that palladacycle 2 has an energy barrier lower than that of palladacycle 1 for the alkylation reaction, consistent with the better catalytic activity of palladacycle 2 seen in the experiments. The palladacycle-phosphine system was found to tolerate a wide range of functional groups and serves as an efficient protocol for the synthesis of α-alkylated products under solvent-free conditions. In addition, the synthetic protocol was successfully applied to prepare donepezil, a drug for Alzheimer's disease, from simple starting materials.
Transition-Metal-Free C-H Hydroxylation of Carbonyl Compounds
Chaudhari, Moreshwar B.,Sutar, Yogesh,Malpathak, Shreyas,Hazra, Anirban,Gnanaprakasam, Boopathy
supporting information, p. 3628 - 3631 (2017/07/15)
Transition metal and reductant free α-C(sp3)-H hydroxylation of carbonyl compounds are reported. This method is promoted by commercially available inexpensive KO-t-Bu and atmospheric air as an oxidant at room temperature. This unified strategy is also very facile for hydroxylation of various carbonyl compound derivatives to obtain quaternary hydroxyl compounds in excellent yield. A preliminary mechanistic investigation, supported by isotope labeling and computational studies, suggests the formation of a peroxide bond and its cleavage by in situ generated enolate.
RuHCl(CO)(PPh3)3-catalyzed R-alkylation of ketones with primary alcohols
Kuwahara, Takashi,Fukuyama, Takahide,Ryu, Ilhyong
supporting information, p. 4703 - 4705,3 (2020/09/16)
The α-alkylation reaction of ketones with primary alcohols to give α-alkylated ketones was achieved using RuHCl(CO)(PPh3) 3 as a catalyst in the presence of Cs2CO3 as a base. This reaction proceeds via an aldol condensation of ketones with aldehydes, formed via transfer dehydrogenation of alcohols, to give α,β-unsaturated ketones, which then undergo transfer hydrogenation with primary alcohols to give R-alkylated ketones and aldehydes, the latter of which participate in the next catalytic cycle. While the reaction of aliphatic primary alcohols was sluggish compared with that of benzylic alcohols, a catalytic amount of 1,10-phenanthroline was found to promote the alkylation dramatically.
Cinchona alkaloid catalyzed enantioselective fluorination of allyl silanes, silyl enol ethers, and oxindoles
Ishimaru, Takehisa,Shibata, Norio,Horikawa, Takao,Yasuda, Naomi,Nakamura, Shuichi,Toru, Takeshi,Shiro, Motoo
supporting information; experimental part, p. 4157 - 4161 (2009/03/11)
(Chemical Equation Presented) Catalytic variant: Allyl silanes and silyl enol ethers 1 are good substrates for the catalytic highly enantioselective fluorodesilylation using a combination of a biscinchona alkaloid, N-fluorobenzenesulfonimide (NFSI), and base (see scheme). Pharmaceutically attractive 3-aryl-3-fluorooxindoles such as 3 can also be synthesized with high enantioselectivity.
