Michael Addition of Nitroalkanes to CF_3CCl_2COCH=CHPh: A Facile Route to Fluorine-containing γ-Nitro Ketones

Nitroalkanes react smoothly with CF_3CCl_2COCH=CHPh via Michael addition in the presence of inorganic bases such as KF/Al2O3 or K2CO3, giving fluorinecontaining γ-nitro ketones in good yields.

Guanidinium Lactate Ionic Liquid: An Efficient and Recycling Catalyst for Michael Addition Reaction

A facile and efficient 1, 4-conjungate addition（Michael addition） reaction of active methylene compounds to aft-unsaturated compounds, catalyzed by guanidinium lactate ionic liquid（IL9）, has been developed. A range of chalcones and nitroalkenes together with active methylene compounds have been converted smoothly to the corresponding products in high yields.

Modification of Nano-alumina Surface by Michael Addition Reaction

A general method for modification of nano-alumina surface is investigated using Michael addition reaction with α,β-unsaturated carbonyl compounds.

[Bmim]OAc Catalyzed Michael Addition of Active Methylene to α,β-Unsaturated Carboxylic Esters and Nitriles

Michael addition of active methylene compounds to α,β-unsaturated carboxylic esters and nitriles was effectively catalyzed by a basic ionic liquid, 1-butyl-3-methylimidazolium acetate（[Bmim]OAc）. The his-addition products were selectively obtained in high yields under mild reaction conditions.

MICHAEL ADDITION OF NITROALKANE TO α,β-UNSATURATED CARBONYL COMPOUNDS ON KF / Al_2O_3/ PEG4000

Michael addition of nitroalkanes to α,β-unsaturated carbonyl compounds occurs in the presence of KF/AI_2O_3/PEG4000 without solvent.Yields are fair to good and work-ups are easy.

Tetramethylguanidium Lactate Ionic Liquid: Catalyst-free Medium for Michael Addition Reaction

A catalyst-free, facile and efficient Michael addition reaction of active methylene compounds as well as nitromethane with chalcones catalyzed by guanidinium lactate ionic liquid was done. A series of chalcones, nitromethane, and active methylene compounds were converted smoothly to the corresponding products in high yields. The simple procedure, very mild conditions, high yields, and reuse of the IL without any loss of catalytic activity make this protocol considerably attractive for academic researches and practical applications.

Diastereoselective Michael Addition of (4'S)-Ethyl-3-(2',2'-Dimethyl-1',3'- dioxolan-4'-yl) acrylate with Furyl Lithium

Michael addition of the chiral alpha,beta -unsaturated ester 2 with furyl lithium proceeded in syn manner with excellent diastereoselectivity. The diastereoselectivity was not affected by the configuration of the double bond in 2.

Michael Addition of Amines to Activated Alkenes Promoted by Zn/NH_4Cl System

A Zn/NH4Cl system was exploited at room temperature to promote the Michael addition reaction of various primary and secondary amines with α,β-unsaturated esters,nitriles,amides,and ketones to give the corresponding saturated amines under the mild condition in high yield.

Michael Additions of Activated Methylene Compounds to α,β-Unsaturated Esters Promoted by Samarium (Ⅲ) Iodide

Promoted by SmI3 β -diketones， β-ketoesters and α -cyano esters were added to α,β -unsaturated esters to form δ-carbonyl esters in mild conditions in moderate to good yields.

Wood pulp industry by-product valorization for acrylate synthesis and bio-based polymer development via Michael addition reaction

It is crucial to adapt the processing of forest bio-resources into biochemicals and bio-based ad-vanced materials in order to transform the current economic climate into a greener economy.Tall oil,as a by-product of the Kraft process of wood pulp manufacture,is a promising resource for the extraction of various value-added products.Tall oil fatty acids-based multifunctional Michael acceptor acrylates were developed.The suitability of developed acrylates for polymerization with tall oil fatty acids-based Michael donor acetoacetates to form a highly cross-linked polymer ma-terial via the Michael addition was investigated.With this novel strategy,valuable chemicals and innovative polymer materials can be produced from tall oil in an entirely new way,making a significant contribution to the development of a forest-based bioeconomy.Two different tall oil-based acrylates were successfully synthesized and characterized.Synthesized acrylates were successfully used in the synthesis of bio-based thermoset polymers.Obtained polymers had a wide variety of mechanical and thermal properties(glass transition temperature from-12.1 to 29.6°C by dynamic mechanical analysis,Young’s modulus from 15 to 1760 MPa,and stress at break from 0.9 to 16.1 MPa).Gel permeation chromatography,Fourier-transform infrared(FT-IR)spectroscopy,matrix-assisted laser desorption/ionization-time of flight mass spectrometry,and nuclear magnetic resonance were used to analyse the chemical structure of synthesized acrylates.In addition,various titration methods and rheology tests were applied to characterize acrylates.The chemical composition and thermal and mechanical properties of the developed polymers were studied by using FT-IR,solid-state nuclear magnetic resonance,thermal gravimetric analy-sis,differential scanning calorimetry,dynamic mechanical analysis,and universal strength testing apparatus.

A novel solid state Michael addition reaction of N-heterocyclic compounds containing active C-H bond

In this paper, a novel solid state Michael-type addition reaction of N-heterocyclic compounds containing the active-CH group was investigated. 3-Methyl-1-phenyl-5-pyrazolone (MPP) and indole (In) reacted with 4-arylmethylene-3-methyl-1-phenyl-5-pyrazolone (1) in the solid state at room temperature to give the corresponding adducts, aryl-4,4'-bis(5-hydroxy-3-methyl-1-phenyl-pyrazolyl) methane (2a-n) and 1-aryl-1-(5'-hydroxy-3'-methyl-1'-phenyl-4'-pyrazolyl)-1-(3 ''-indolyl) methane (3a-n), respectively. This is a feasible method for preparing the compound which contains two heterocyclic groups on the same carbon.

Recent progress in Michael addition-based fluorescent probes for sulfur dioxide and its derivatives

Sulfur dioxide（SO_2） is a harmful environmental pollutant. Inhaled SO_2 can be rapidly hydrated into its derivatives, bisulfite（HSO_3^-） and sulfite（SO_3^（2-））. SO_2 derivatives are well known as preservatives and antioxidants, which are used in food and beverages to prevent oxidation and bacterial growth. Although SO_2 can be endogenously generated in mammals and exhibits unique bioactivities in regulating cardiovascular function, excessive SO_2 and its derivatives have toxic effects on humans and animals for triggering adverse reactions and diseases. A large number of fluorescent probes for SO_2 and its derivatives have been designed and reported due to their high sensitivity and selectivity, high temporal and spatial resolution, non-invasive and non-destructive detection as well as real-time visualization in situ. In this review, we have summarized the recent progress of Michael addition-based fluorescent probes for SO_2 and its derivatives. These probes are categorized and concluded according to the different α,β-unsaturated compounds（i.e., Michael acceptors）. The design strategies, sensing performances, detection mechanisms and applications of these probes are discussed in detailed. Finally, a general overview about the design of probes for SO_2 and its derivatives is provided, which will facilitate the development of ideal probes for SO_2 and its derivatives.

Enantioselective Synthesis of N-Phenyl-dihydropyrano[2,3-c]-pyrazoles via Cascade Michael Addition/Thorpe-Ziegler Type Cyclization Catalyzed by a Chiral Squaramide

Enantioselective synthesis of biologically active dihydropyrano[2,3-c]pyrazoles has been achieved through a squaramide-catalysed Michael addition/Thorpe-Ziegler type cyclization cascade reaction between arylidenepyra-zolones and malononitrile.A series of optically active dihydropyano[2,3-c]pyrazoles were obtained in excellent yields(up to 99%)and moderate to good enantioselectivities(up to 79%ee)under mild reaction conditions.

Bismuth trichloride-catalyzed oxy-Michael addition of water and alcohol to α,β-unsaturated ketones

An efficient method was developed for the conjugate addition of water to various a,β-unsaturated ketones by using bismuth(Ⅲ)chlo ride as a catalyst.The reactions proceeded smoothly in the presence of a catalytic amount of BiCl3(20 mol%)in aqueous media to furnish a variety of synthetically usefulβ-hydroxyl ketones in moderate to good yields.Apart from water molecule,various alcohols could also be employed as nucleophiles to react withα,β-unsaturated ketones,leading toβ-alkoxyl ketones in modest to high yields.In addition,the mild reaction conditions also entailed the conjugate addition reactions to proceed with the tolerance to a range of functional groups.

Computational studies of cinchona alkaloid-catalyzed asymmetric Michael additions

Cinchona alkaloid is one of the most effective organocatalysts that facilitate a wide range of transformations. To elucidate the mechanistic details and especially the origins of the observed high enantio- and diastereoselectivities, computational chemists have contributed dramatic efforts in this important area. This review covers the recent computational studies on the cinchona alkaloid-catalyzed asymmetric Michael additions, including both C-C and C-S bond formations, to present a general viewpoint of these fruitful advances. Based on the types of bond formation and the cinchona alkaloid catalysts, key information regarding the activation model and the origins of enantioselectivities is discussed.

Organophosphine bearing multiple hydrogen-bond donors for asymmetric Michael addition reaction of 1-oxoindane-2-carboxylic acid ester via dual-reagent catalysis

Multiple hydrogen bonds containing nucleophilic phosphines derived from dipeptide dual-reagents catalyzed asymmetric Michael addition reactions between indene esters and activated olefins in high yields and good to excellent enantioselectivities under mild reaction conditions.The success of current highly selective reactions should provide inspiration for expansion to other reactions and would open up new paradigms for the synthesis of indanone derivatives bearing chiral quaternary carbon centers.

A simple,efficient and green procedure for Michael addition catalyzed by [C_4dabco]OH ionic liquid

A dabco-based basic ionic liquid,1-butyl-4-aza-1-azaniabicyclo[2.2.2]octane hydroxide,has been developed as a catalyst for a convenient and rapid method for the Michael addition of active methylene compounds to a b-unsaturated carboxylic esters and nitriles.The method is very simple,and the yields are very high.The catalyst can be recycled several times without much loss of activity.

Colorimetric and fluorimetric detection of cysteine: Unexpected Michael addition–elimination reaction

The synthesis of three isomers based on Michael addition mechanism for the detection of sulfurcontaining species in aqueous solution is described. These compounds are constructed by conjugating an enone to a coumarin fluorophore. A substituted-phenyl（o, m, or p-） was appended at the carbonyl carbon to adjust the reactivity. The experimental results showed that（E）-7-（diethylamino）-3-（3-（3-hydroxyphenyl）-3-oxoprop-1-en-1-yl）-2H-chromen-2-one（m-QPS） and（E）-7-（diethylamino）-3-（3-（4-hydroxyphenyl）-3-oxoprop-1-en-1-yl）-2H-chromen-2-one（p-QPS） barely react with sulfur-containing nucleophiles, while（E）-7-（diethylamino）-3-（3-（2-hydroxyphenyl）-3-oxoprop-1-en-1-yl）-2H-chromen-2-one（o-QPS） exhibited a fast response toward sulfite, sulfide and thiols in DMSO/phosphate buffer（2：1）. The above results are probably due to the intramolecular H-bonding activated Michael addition.More interestingly, cysteine triggered unusual photophysical responses of o-QPS： the original absorption（488 nm） and emission peaks（573 nm） underwent significant blue shifts initially and then recovered,which might be caused by the Michael addition and elimination reaction, respectively.

Enantioselective Construction of Functionalized Thiochromans via Squaramide-Catalyzed Asymmetric Cascade Sulfa-Michael/Michael Addition

An efficient enantioselective cascade sulfa-Michael/Michael addition reaction of trans-3-(2-mercaptophenyl)-2-propenoic acid ethyl ester with nitroalkenes catalyzed by a chiral squaramide catalyst was disclosed.This cascade reaction afforded thiochroman derivatives with three contiguous stereocenters in high yields(up to 94%),excellent diastereoselectivities(up to>25∶1 dr)and enantioselectivities(up to 99% ee).