Grignard Addition Reactions to 1,4-Difunctionalized But-2-ynes

1993 ◽  
Vol 46 (11) ◽  
pp. 1657 ◽  
Author(s):  
AN Desilva ◽  
CL Francis ◽  
AD Ward
Keyword(s):  
Good Yield ◽  
Addition Product ◽  
Grignard Reagents ◽  
High Yield ◽  
Addition Reactions ◽  
Grignard Addition ◽  
Trisubstituted Alkenes ◽  
Phenylmagnesium Bromide

Trisubstituted alkenes of E geometry have been prepared by anti addition of Grignard reagents to 1,4-difunctionalized but-2-ynes. Addition of primary, secondary and aromatic Grignard reagents to but-2-yne-1,4-diol provided (E)-2-substituted but-2-ene-1,4-diols as major products along with the corresponding 2-substituted buta-2,3-dien-1-ols. Addition of phenylmagnesium bromide to the mono- and di-methyl ethers of but-2-yne-1,4-diol gave 2,3-diphenyl-1,3-diene. Treatment of 4-dimethylaminobut-2-yn-1-ol with primary alkyl and alkenyl Grignard reagents afforded the 2-substituted anti addition product regiospecifically, stereospecifically and in high yield. Reaction of 1-dimethylamino-4-methoxybut-2-yne with butylmagnesium bromide provided only the 3-substituted anti addition product in good yield.

Study of CuSCN Catalyzed Conjugate Addition Reactions of Grignard Reagents to Substituted Chalcones with Dilithium Tetrachloromanganate and their Biological Activities

2021 ◽  
Vol 6 (2) ◽  
pp. 141-147
Author(s):  
Mohan B. Kale ◽  
Shrikant B. Jagtap ◽  
Santosh S. Devkate
Keyword(s):  
Escherichia Coli ◽  
Grignard Reagent ◽  
Biological Activities ◽  
Homogeneous Solution ◽  
Addition Product ◽  
Conjugate Addition ◽  
Nitrogen Atmosphere ◽  
Grignard Reagents ◽  
Addition Reactions ◽  
Lower Temperature

The regioselective 1,4-addition reactions of copper thiocyanate catalyzed Grignard reagents to the substituted chalcones are reported. The homogeneous solution of dilithium tetrachloromanganate is used to transmetallate magnesium by using manganese. It adds regio-selectively to substituted chalcone derivatives and forms 1,4-addition products with higher yield under nitrogen atmosphere and at a lower temperature. It have been observed that manganese from dilithium tetrachloromanganate reagent replaces magnesium from Grignard reagent and adds regioselectively by 1,4-addition manner utilizing copper thiocyanate as a catalyst. The course of the reaction in the absence of dilithium tetrachloromanganate reagent was also studied and obtained a mixture of 1,2-addition and 1,4-addition products. In presence of dilithium tetrachloromanganate reagent, a good regio-selectivity and higher yield of desired 1,4-addition product were obtained. All the synthesized compounds were also evaluated for their antibacterial activity against Staphylococcus aureus (Gram-positive), Escherichia coli (Gramnegative) and antifungal activity against Aspergillus niger.

Ionic dimerisation of trifluoropropenenitrile and its addition reactions with methyl trifluoropropenoate

1980 ◽  
Vol 45 (2) ◽  
pp. 406-414 ◽  
Author(s):  
Jiří Svoboda ◽  
Oldřich Paleta ◽  
Václav Dědek
Keyword(s):  
Reaction Mechanism ◽  
Proton Transfer ◽  
Substituent Effect ◽  
Solvent Molecule ◽  
Addition Product ◽  
Potassium Fluoride ◽  
Relative Reactivity ◽  
Addition Reactions ◽  
Tertiary Amines ◽  
Optimum Conditions

Dimerisation of trifluoropropenenitrile (I) in the presence of potassium fluoride and tertiary amines afforded a mixture of stereoisomeric perfluoro-4-methyl-pentenedinitriles (II), higher-boiling compounds, and 2,3,3,3-tetrafluoropropanenitrile (III) which arises by proton transfer from the solvent molecule. Under optimum conditions, product II was obtained in about 50% yield. Reaction of the nitrile I with methyl trifluoropropenoate (IV) gave, besides the dimers II and V, the product of addition of the nitrile I to the propenoate, IV, i.e. methyl 4-cyanoperfluoro-2-pentenoate (VI), and the addition product of the propenoate IV to the nitrile I, i.e. methyl 4-cyanoperfluoro-2-methyl-3-butenoate (VII). The relative reactivity if I and IV is discussed. The ratio of stereoisomers in II, V, VI and VII indicates that the magnitude of the steric substituent effect, operating in the reaction mechanism, decreases in the order -CFCF3.(COOCH3) > -CFCF3(CN) > -COOCH3 > -CN.

scholarly journals Recoverable Phospha-Michael Additions Catalyzed by a 4-N,N-Dimethylaminopyridinium Saccharinate Salt or a Fluorous Long-Chained Pyridine: Two Types of Reusable Base Catalysts

Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 1159
Author(s):  
Eskedar Tessema ◽  
Vijayanath Elakkat ◽  
Chiao-Fan Chiu ◽  
Jing-Hung Zheng ◽  
Ka Long Chan ◽  
...  
Keyword(s):  
Michael Addition ◽  
Polar Solvent ◽  
Addition Reaction ◽  
High Yield ◽  
Addition Reactions ◽  
Polar Solvents ◽  
Unsaturated Bond ◽  
Base Catalysts ◽  
Michael Additions

Phospha-Michael addition, which is the addition reaction of a phosphorus-based nucleophile to an acceptor-substituted unsaturated bond, certainly represents one of the most versatile and powerful tools for the formation of P-C bonds, since many different electrophiles and P nucleophiles can be combined with each other. This offers the possibility to access many diversely functionalized products. In this work, two kinds of basic pyridine-based organo-catalysts were used to efficiently catalyze phospha-Michael addition reactions, the 4-N,N-dimethylaminopyridinium saccharinate (DMAP·Hsac) salt and a fluorous long-chained pyridine (4-Rf-CH2OCH2-py, where Rf = C11F23). These catalysts have been synthesized and characterized by Lu’s group. The phospha-Michael addition of diisopropyl, dimethyl or triethyl phosphites to α, β-unsaturated malonates in the presence of those catalysts showed very good reactivity with high yield at 80–100 °C in 1–4.5 h with high catalytic recovery and reusability. With regard to significant catalytic recovery, sometimes more than eight cycles were observed for DMAP·Hsac adduct by using non-polar solvents (e.g., ether) to precipitate out the catalyst. In the case of the fluorous long-chained pyridine, the thermomorphic method was used to efficiently recover the catalyst for eight cycles in all the reactions. Thus, the easy separation of the catalysts from the products revealed the outstanding efficacy of our systems. To our knowledge, these are good examples of the application of recoverable organo-catalysts to the DMAP·Hsac adduct by using non-polar solvent and a fluorous long-chained pyridine under the thermomorphic mode in phospha-Michael addition reactions.

Asymmetric Addition Reactions of Grignard Reagents to Chiral 2-Trifluoromethyl tert-Butyl (Ellman) Sulfinimine—Ethanol Adducts.

ChemInform ◽  
2006 ◽  
Vol 37 (29) ◽  
Author(s):  
Scott D. Kuduk ◽  
Christina Ng Di Marco ◽  
Steven M. Pitzenberger ◽  
Nancy Tsou
Keyword(s):  
Grignard Reagents ◽  
Addition Reactions ◽  
Asymmetric Addition ◽  
Tert Butyl

Redoxreaktionen mit cyclopeptidartigen Chinolinderivaten als lipophil-maskierte NAD-Modellverbindungen / Redox Reactions with Cyclopeptide-Like Quinoline Derivatives as Lipophilic NAD Model Compounds

1987 ◽  
Vol 42 (9) ◽  
pp. 1159-1166 ◽  
Author(s):  
Sabine Bohnert ◽  
Wolf-H. Gündel
Keyword(s):  
Amino Acids ◽  
Redox Reactions ◽  
Model Compound ◽  
Addition Product ◽  
High Yield ◽  
Quinoline Derivatives ◽  
Model Compounds ◽  
Quaternary Salts

Quaternary salts of the amides of N-(3-quinolinecarbonyl) amino acids (7) cyclise under the influence of base to give fourteen membered rings (9). This dimerisation is a reaction with high diastereoselectivity. The addition product 9 can be regarded as lipophilic, masked NAD model compound: 9 oxidizes 2-propanol under ZnCl2 catalysis to give in high yield acetone and the 1.4-dihydroquinoline.

scholarly journals Cross-Coupling Reaction of Allylic Ethers with Aryl Grignard Reagents Catalyzed by a Nickel Pincer Complex

Molecules ◽  
2019 ◽  
Vol 24 (12) ◽  
pp. 2296 ◽  
Author(s):  
Toru Hashimoto ◽  
Kei Funatsu ◽  
Atsufumi Ohtani ◽  
Erika Asano ◽  
Yoshitaka Yamaguchi
Keyword(s):  
Coupling Reaction ◽  
Cross Coupling ◽  
Grignard Reagents ◽  
High Yield ◽  
Pincer Complex ◽  
Cross Coupling Reaction ◽  
Allylic Aryl Ethers ◽  
Aryl Ethers ◽  
Type Nickel ◽  
Allylic Ethers

A cross-coupling reaction of allylic aryl ethers with arylmagnesium reagents was investigated using β-aminoketonato- and β-diketiminato-based pincer-type nickel(II) complexes as catalysts. An β-aminoketonato nickel(II) complex bearing a diphenylphosphino group as a third donor effectively catalyzed the reaction to afford the target cross-coupled products, allylbenzene derivatives, in high yield. The regioselective reaction of a variety of substituted cinnamyl ethers proceeded to give the corresponding linear products. In contrast, α- and γ-alkyl substituted allylic ethers afforded a mixture of the linear and branched products. These results indicated that the coupling reaction proceeded via a π-allyl nickel intermediate.

scholarly journals The monoblocking of symmetrical diketones on insoluble polymer supports

1983 ◽  
Vol 61 (7) ◽  
pp. 1405-1409 ◽  
Author(s):  
Zhang-Huang Xu ◽  
Colin R. McArthur ◽  
Clifford C. Leznoff
Keyword(s):  
Acid Hydrolysis ◽  
Nmr Spectra ◽  
High Yield ◽  
Styrene Copolymer ◽  
Polymer Supports ◽  
Vicinal Diol ◽  
Insoluble Polymer ◽  
C Nmr ◽  
Phenylmagnesium Bromide

A 1% crosslinked divinylbenzene–styrene copolymer, incorporating vicinal diol groups or their isopropylidenc precursors, was used to form the monoacetals of the symmetrical diketones, p-diacetylbenzene, 1,2-cyclohexanedione, 1,3-cyclohexanedionc, 1,4-cyclohexanedione, and 2,5-hexanedione. The free ketone groups reacted with phenylmagnesium bromide to give, in high yield, after acid hydrolysis from the polymer, the expected products such as 3-phenyl-2-cyclohexen-1-one from 1,3-cyclohexanedione. The 13C nmr spectra of some polymer-bound substrates and simple analogs are described.

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