20913-05-7Relevant articles and documents
Silica gel-promoted synthesis of multisubstituted spiroindolenines from tryptamines and γ-chloro-α,β-unsaturated ketones
Liu, Qiang-Qiang,Zheng, Chao,You, Shu-Li
, (2021)
Here we report a one-pot synthesis of multisubstituted spiroindolenines from a series of tryptamine derivatives with γ-chloro-α,β-unsaturated ketones. The reaction sequence consists of base-induced condensation and silica gel-promoted intramolecular Michael addition. The target molecules are afforded in up to 90% yield with up to >20:1 diastereoselectivity.
An efficient keim-type catalyst based on an electron-poor P,O-chelate; tuning the selectivity of ethylene oligomerisation towards short α-olefins
Kuhn, Pierre,Semeril, David,Jeunesse, Catherine,Matt, Dominique,Lutz, Pierre,Welter, Richard
, p. 1477 - 1481 (2005)
The tertiary phosphane Ph2P-pzONa, in which the phosphorus atom is substituted by an electron-withdrawing pyrazolonato unit, reacts with trans-[NiPhCl(PPh3)2] to afford quantitatively trans-P,P′-[NiPh(Ph2P-pzO)(
Formation of epoxychromeno[4,3-c]isoquinolines through diastereoselective one-pot IMDA reaction of 4-chloro-3-[(1E)-3-oxo-3-phenyl-1-propen-1-yl]-2H-chromen-2-one and furfurylamine
Alizadeh, Abdolali,Amir Ashjei Asalemi, Kaveh,Farajpour, Behnaz,Halvagar, Mohammad Reza
, p. 3393 - 3399 (2020)
Abstract: An intramolecular Diels–Alder mediated reaction of (2E)-3-(4-chloro-2-methylene-2H-chromen-3-yl)-1-phenyl-2-propen-1-one, which was obtained in situ from the reaction of 4-chloro-2-oxo-2H-chromene-3-carbaldehyde and Wittig reagent, with furfuryl
Benzoylmethylenetriphenylphosphorane, C26H21OP
Kalyanasundari, M.,Panchanatheswaran, K.,Parthasarathi, V.,Robinson, Ward T.,Wen, Huo
, p. 1738 - 1741 (1994)
The air-stable phosphorane (2-oxo-2-phenyltriphenylphosphoniumethylide) is shown to be a resonance hybrid of an ylene, ylidic and enolate canonical assembly.The geometry around the P atom is nearly tetrahedral.The O atom is oriented cis to the P atom.The phenyl ring of the benzoyl group is twisted with respect to the plane containing the carbonyl group.
Stereoselective Visible-Light Catalyzed Cyclization of Bis(enones): A Viable Approach to the Synthesis of Enantiomerically Enriched Cyclopentane Rings
Medici, Fabrizio,Resta, Simonetta,Presenti, Piero,Caruso, Lucia,Puglisi, Alessandra,Raimondi, Laura,Rossi, Sergio,Benaglia, Maurizio
supporting information, p. 4521 - 4524 (2021/06/12)
Photoredox catalytic cyclization of aryl enones in the presence of visible light, promoted either by metals or organic dyes, represent a valuable strategy for the synthesis of cycloalkanes. The development of a stereoselective version of such transformation, in the presence of the metal-free catalyst Eosin Y was studied, with the aim to realize an efficient protocol for the in-flow synthesis of enantiomerically enriched functionalized cyclopentane rings, taking advantage of the flow reactors technology. The use of a chiral auxiliary on the bisenone to be cyclized offers a straightforward and convenient option to exert a stereocontrol on the light-driven cyclization. By exploiting Evans’ oxazolidinones, the stereoselective light-driven cyclization affords, after the removal of the chiral auxiliary, a functionalized 1,2-trans cyclopentane ring in up to 83/17 enantiomeric ratio. When the reaction was performed in continuo, in a homemade coil photoreactor, high yields were observed. The cyclization was also successfully realized in a 3D-printed mesoreactor, without any change in the diastereoseletctivity of the process.
Synthesis of tertiary phosphine oxides by alkaline hydrolysis of quaternary phosphonium zwitterions using excess t-BuOK and stoichiometric water
Zhong, Chun-Hong,Huang, Wenhua
supporting information, p. 1537 - 1546 (2021/01/07)
Hydrolysis of quaternary arylphosphonium zwitterions bearing COO? and those in situ generated from the corresponding salts bearing Ac or OH at the aryl ring by using excess t-BuOK and stoichiometric water affords tertiary arylphosphine oxides in moderate to excellent yield, in contrast to hydrolysis of these zwittertion or salts in aqueous NaOH that mainly provides phosphine oxides with the loss of the aryl group. Under the t-BuOK/water conditions, hydrolysis of carbonyl stabilized ylides Ph3P = CHCOR (R = Ph, Me, and OEt), which partially exist as phosphonium enolates, prefers to produce Ph2P(O)CH2COR. Further reduction of Ph2P(O)CH2COMe by PhSiH3 allows the preparation of Ph2PCH2COMe in 43% yield.
Substituent effects in the formation of a few acenaphthenone-2-ylidene ketones and their molecular docking studies and in silico ADME profile
A, Jesna,Jacob, Jomon P.,Kuriakose, Daly,Thumpakara, Roshini K.
, (2020/09/15)
We observed intriguing substituent effects in the reaction between 4-substituted acetophenones and acenaphthenequinone in the presence of KOH in methanol. In all cases, expected Claisen-Schimdt condensation was the first step. However, depending on the nature of 4-substituent on acetophenone, the initially formed condensation product remain unchanged or underwent Domino sequence of reactions to give three different 2:2 adducts arising through three distinct pathways. The interactions of acenaphthenone-2-ylidene ketones with the target proteins were performed by molecular docking studies. The prediction of in silico ADME belongings of the synthesized compounds revealed substantial drug-likeness characters based on Lipinski's rules.
Selective Construction of C?C and C=C Bonds by Manganese Catalyzed Coupling of Alcohols with Phosphorus Ylides
Liu, Xin,Werner, Thomas
supporting information, p. 1096 - 1104 (2020/12/31)
Herein, we report the manganese catalyzed coupling of alcohols with phosphorus ylides. The selectivity in the coupling of primary alcohols with phosphorus ylides to form carbon-carbon single (C?C) and carbon-carbon double (C=C) bonds can be controlled by the ligands. In the conversion of more challenging secondary alcohols with phosphorus ylides the selectivity towards the formation of C?C vs. C=C bonds can be controlled by the reaction conditions, namely the amount of base. The scope and limitations of the coupling reactions were thoroughly evaluated by the conversion of 21 alcohols and 15 ylides. Notably, compared to existing methods, which are based on precious metal complexes as catalysts, the present catalytic system is based on earth abundant manganese catalysts. The reaction can also be performed in a sequential one-pot reaction generating the phosphorus ylide in situ followed manganese catalyzed C?C and C=C bond formation. Mechanistic studies suggest that the C?C bond was generated via a borrowing hydrogen pathway and the C=C bond formation followed an acceptorless dehydrogenative coupling pathway. (Figure presented.).
A Convenient Formal [4+2] Heterocylization Route to Bis(triflyl)tetrahydroquinolines
Lázaro-Milla, Carlos,Almendros, Pedro
supporting information, p. 13534 - 13538 (2021/08/13)
We report the sustainable and efficient synthesis of a new type of quinoline derivatives bearing one or two SO2CF3 groups. The protocol is metal-, catalyst- and irradiation-free, involves the use of readily available and stable precursors, and avoids the formation of side products. Also, the mild conditions of the process allow the tolerance of a wide range of functional groups.
Rh(iii)-catalyzed diastereoselective cascade annulation of enone-tethered cyclohexadienonesviaC(sp2)-H bond activation
Chegondi, Rambabu,Jadhav, Sandip B.,Maurya, Sundaram,Navaneetha, N.
supporting information, p. 13598 - 13601 (2021/12/23)
Herein, we report highly diastereoselective arylative cyclization of enone-tethered cyclohexadienonesviaRh(iii)-catalyzed C-H activation ofN-methoxybenzamides. This reaction proceeds through the formation of a five-membered rhodacycle followed by bis-Michael cascade annulation to access functionalized bicyclic scaffolds with four contiguous stereocenters with a broad substrate scope. These products have excellent functional handles, allowing further synthetic transformation to increase the structural complexity. Furthermore, mechanistic studies of arylative cyclization and a gram-scale experiment are also presented.
