Michael Addition of Indoles to Enones Catalyzed by a Cationic Iron Salt

Synthesis ◽  
2021 ◽  
Author(s):  
Takashi Nishikata ◽  
Tsukasa Inishi ◽  
Goki Hirata
Keyword(s):  
Lewis Acid ◽  
Michael Addition ◽  
Iron Catalyst ◽  
Unsaturated Ester ◽  
Iron Salt ◽  
Michael Additions ◽  
The Michael Addition

AbstractIndoles are one of the most valuable nucleophiles in Michael additions catalyzed by a proper Lewis acid. In this paper, we found that a cationic iron salt is effective to carry out the Michael addition of indoles. β-Mono- and disubstituted enones reacted smoothly with indoles under our conditions. The cationic iron catalyst is very active, and the maximum TON was up to 425. Moreover, cationic iron-catalyzed conditions enabled a chemoselective Michael addition of a substrate possessing both enone and α,β-unsaturated ester moieties.

scholarly journals Post-polymerisation modification of bio-derived unsaturated polyester resins via Michael additions of 1,3-dicarbonyls

2016 ◽  
Vol 7 (8) ◽  
pp. 1650-1658 ◽  
Author(s):  
T. J. Farmer ◽  
J. H. Clark ◽  
D. J. Macquarrie ◽  
J. K. Ogunjobi ◽  
R. L. Castle
Keyword(s):  
Michael Addition ◽  
Unsaturated Polyester ◽  
Polyester Resins ◽  
Unsaturated Polyesters ◽  
Unsaturated Polyester Resins ◽  
Michael Additions ◽  
First Time ◽  
The Michael Addition

A rapid (5 min), solventless and heterogeneously catalysed methodology is demonstrated for the first time for the Michael addition of 1,3-dicarbonyls to biomass derived unsaturated polyesters.

Catalytic Enantioselective Michael Additions to Unsaturated Ester Derivatives Using Chiral Copper(II) Lewis Acid Complexes

1999 ◽  
Vol 1 (6) ◽  
pp. 865-868 ◽  
Author(s):  
David A. Evans ◽  
Michael C. Willis ◽  
Jeffrey N. Johnston
Keyword(s):  
Lewis Acid ◽  
Unsaturated Ester ◽  
Michael Additions

Carcinogenicity of lactones. V. The reactions of 4-hydroxypent-2-enoic acid lactone with α-toluenethiol, benzylamine, methylamine, imidazole, and guanidine

1970 ◽  
Vol 48 (10) ◽  
pp. 1574-1578 ◽  
Author(s):  
J. Bryan Jones ◽  
Jill N. Barker
Keyword(s):  
Michael Addition ◽  
Ring Opening ◽  
Lactone Ring ◽  
Addition Product ◽  
Enoic Acid ◽  
Michael Additions ◽  
Ring Opening Reactions ◽  
Acid Lactone ◽  
Ph Range ◽  
The Michael Addition

The Michael additions of α-toluenethiol, methylamine, and benzylamine to 4-hydroxypent-2-enoic acid lactone have been confirmed to be facile. The analogous additions of imidazole and glycine amide are much less readily accomplished and no stable Michael addition product could be detected with guanidine as the base. In the pH range 6–9, subsequent lactone ring opening reactions of the Michael addition products were observed only when methylamine (pKa 9.3) and benzylamine (pKa 10.6) were used as nucleophiles.

scholarly journals Importance of the N-terminal proline for the promiscuous activity of 4-oxalocrotonate tautomerase (4-OT)

2016 ◽  
Vol 81 (8) ◽  
pp. 871-881 ◽  
Author(s):  
Jelena Lazic ◽  
Jelena Spasic ◽  
Djordje Francuski ◽  
Zorana Tokic-Vujosevic ◽  
Jasmina Nikodinovic-Runic ◽  
...  
Keyword(s):  
Michael Addition ◽  
Structural Changes ◽  
In Silico Analysis ◽  
Cell System ◽  
Michael Additions ◽  
Lysine Residues ◽  
Negative Effect ◽  
Michael Acceptors ◽  
Organocatalytic Reactions ◽  
The Michael Addition

Michael addition of aldehydes to nitroolefins is an effective method to obtain useful chiral ?-nitroaldehydes. ?-Nitroaldehydes are precursors for chiral ?-aminobytiric acid analogues which have numerous pharmacological activities and are used for treatment of neurological disorders. A whole-cell system based on recombinantly expressed 4-oxalocrotonate tautomerase (4-OT) has been developed and shown to be an effective biocatalyst for Michael addition of branched aldehydes to ?-nitrostyrenes. The aim of this study was to investigate the influence of the substitution of the N-terminal proline with lysine and arginine both containing the reactive ?-amino group, on the Michael addition catalyzed by 4-OT. Firstly, the effect of these mutations was examined by in silico analysis, followed by generation of three terminal ly-sine mutants. The generated mutants, 4-OT_K, 4-OT_PK and 4-OT_KK were tested for the ability to utilise ?-nitrostyrene (1), (E)-2-(thiophene-2-yl)nitroethen (2) and p-chloro-trans-?-nitrostyrene (3) as Michael acceptors with isobutanal as the donor. For comparison, the lithium salt of lysine was used in the same organocatalytic reactions. In general, the introduction of lysine had a negative effect on Michael additions based on overall product yields. However, additional lysine residues at the N-terminus of the protein resulted in structural changes that enhanced the activity towards 2 and 3. Therefore, the N-terminal proline is important for the 4-OT catalysed Michael-additons, but it is not essential.

Enantioselective Michael Addition of Malonates to Enones

2020 ◽  
Vol 24 (7) ◽  
pp. 746-773
Author(s):  
Péter Bakó ◽  
Tamás Nemcsok ◽  
Zsolt Rapi ◽  
György Keglevich
Keyword(s):  
Michael Addition ◽  
Activity Relationship ◽  
Chalcone Derivatives ◽  
Michael Additions ◽  
Michael Reactions ◽  
Structure Activity ◽  
Cyclic Enones ◽  
Michael Acceptors ◽  
Relationship Of ◽  
Enantioselective Catalysts

: Many catalysts were tested in asymmetric Michael additions in order to synthesize enantioenriched products. One of the most common reaction types among the Michael reactions is the conjugated addition of malonates to enones making it possible to investigate the structure–activity relationship of the catalysts. The most commonly used Michael acceptors are chalcone, substituted chalcones, chalcone derivatives, cyclic enones, while typical donors may be dimethyl, diethyl, dipropyl, diisopropyl, dibutyl, di-tert-butyl and dibenzyl malonates. This review summarizes the most important enantioselective catalysts applied in these types of reactions.

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.

Chemoselective Double Michael Addition: Synthesis of 2,6-Diarylspiro[Cyclohexane-1,3′-Indoline]-2′,4-Diones via Addition of Indolin-2-One to Divinyl Ketones

2017 ◽  
Vol 41 (3) ◽  
pp. 168-171 ◽  
Author(s):  
Zheng Li ◽  
Jiasheng Li ◽  
Jingya Yang
Keyword(s):  
Michael Addition ◽  
High Yield ◽  
Reaction Conditions ◽  
Michael Additions

Seventeen examples of 2,6-diarylspiro[cyclohexane-1,3′-indoline]-2′4-diones were efficiently prepared by the Cs2CO3-catalysed chemoselective double Michael additions of indolin-2-one to divinyl ketones. This method has the advantage of high chemoselectivity, mild reaction conditions, high yield and atom- and step-economy.

Study of the Michael addition of β-cyclodextrin–thiol complexes to conjugated alkenes in water

2005 ◽  
pp. 669-671 ◽  
Author(s):  
N. Srilakshmi Krishnaveni ◽  
K. Surendra ◽  
K. Rama Rao
Keyword(s):  
Michael Addition ◽  
The Michael Addition
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