Highly Enantioselective Michael Addition of Cyclic Diketones to β,γ-Unsaturated α-Keto Esters Catalyzed by Squaramide Organocatalyst

Synthesis ◽  
2022 ◽  
Author(s):  
Zhi-Wei Ma ◽  
Chuan-Chuan Wang ◽  
Quan-Jian Lv ◽  
Xiao-Pei Chen ◽  
Ai-Qin Li ◽  
...  
Keyword(s):  
Michael Addition ◽  
Large Scale ◽  
Catalyst System ◽  
Catalyst Loading ◽  
Reaction Conditions ◽  
Keto Esters ◽  
Bicyclic Compounds ◽  
Asymmetric Michael Addition ◽  
High Yields ◽  
Low Catalyst Loading

AbstractA new tertiary amine-squaramide organocatalyst has been developed and applied to the asymmetric Michael addition of cyclic diketones to β,γ-unsaturated α-keto esters. The catalyst system performed well with a low catalyst loading of 1 mol% under mild reaction conditions. A series of synthetically and pharmaceutically useful chiral bicyclic compounds were obtained in high yields (up to 97%) with excellent enantioselectivities (up to 99 % ee). Furthermore, this catalytic system can be used efficiently in large-scale reactions with the yields and enantioselectivities being maintained.

scholarly journals Enantioselective Michael addition of 2-hydroxy-1,4-naphthoquinones to nitroalkenes catalyzed by binaphthyl-derived organocatalysts

2012 ◽  
Vol 8 ◽  
pp. 699-704 ◽  
Author(s):  
Saet Byeol Woo ◽  
Dae Young Kim
Keyword(s):  
Michael Addition ◽  
Catalyst Loading ◽  
High Yields ◽  
Low Catalyst Loading

The highly enantioselective Michael addition of 2-hydroxy-1,4-naphthoquinones to nitroalkenes, promoted by binaphthyl-modified chiral bifunctional organocatalysts is described. This reaction afforded the chiral functionalized naphthoquinones in high yields (81–95%) and excellent enantioselectivities (91–98% ee) under low catalyst loading (1 mol %).

Potassium Hydroxide Catalysed Intermolecular Aza-Michael Addition of 3-Cyanoindole to Aromatic Enones

Synlett ◽  
2017 ◽  
Vol 28 (10) ◽  
pp. 1227-1231 ◽  
Author(s):  
Jingya Yang ◽  
Tianyuan Li ◽  
Hongyan Zhou ◽  
Nana Li ◽  
Dongtai Xie ◽  
...  
Keyword(s):  
Reaction Temperature ◽  
Michael Addition ◽  
Potassium Hydroxide ◽  
Michael Reaction ◽  
Pharmaceutical Compounds ◽  
Catalyst Loading ◽  
Good Substrate ◽  
Substrate Tolerance ◽  
High Yields ◽  
Low Catalyst Loading

Indole is one of the utmost important heterocycles as it is an essential nucleus of many pharmaceutical compounds. Its aza-Michael reaction, however, is underdeveloped because of the moiety’s inherent characteristics. Here, a potassium hydroxide catalysed intermolecular aza-Michael reaction of 3-cyanoindole with aromatic enones is described. A variety of chalcone derivatives are well tolerated and afford the corresponding N-adducts in moderate to high yields. The use of a cheap catalyst, low catalyst loading, mild reaction temperature, and good substrate tolerance make this procedure a direct and facile method for the preparation of N1-functionalized indoles.

scholarly journals Asymmetric Michael Addition of Malononitrile with Chalcones via Rosin-Derived Bifunctional Squaramide

Catalysts ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 14
Author(s):  
Ning Lin ◽  
Qiu-Xiang Wei ◽  
Li-Hua Jiang ◽  
Yan-Qiu Deng ◽  
Zhen-Wei Zhang ◽  
...  
Keyword(s):  
Michael Addition ◽  
Carbonyl Compounds ◽  
Catalyst Loading ◽  
Facile Synthesis ◽  
Asymmetric Michael Addition ◽  
High Yields ◽  
Experimental Findings

A rosin-derived bifunctional squaramide catalyzed asymmetric Michael addition of malononitrile with chalcones was discovered. This protocol provides a methodology for the facile synthesis of chiral γ-cyano carbonyl compounds in high yields and enantioselectivities (up to 99% yield and 90% ee) with a lower catalyst loading (0.3 mol%). The predominant R-configured adducts were obtained by this organocatalystic reaction, according to the experimental findings.

scholarly journals Asymmetric Synthesis of Tetrahydrobenzofurans and Annulated Dihydropyrans via Cooperative One-Pot Organo- and Silver-Catalysis

Synthesis ◽  
2016 ◽  
Vol 48 (19) ◽  
pp. 3207-3216 ◽  
Author(s):  
Uğur Kaya ◽  
Pankaj Chauhan ◽  
Kristina Deckers ◽  
Rakesh Puttreddy ◽  
Kari Rissanen ◽  
...  
Keyword(s):  
Asymmetric Synthesis ◽  
Michael Addition ◽  
Catalyst Loading ◽  
One Pot ◽  
Silver Catalysis ◽  
Asymmetric Michael Addition ◽  
Low Catalyst Loading

A low catalyst loading of a squaramide (0.5 mol%) and a silver(I) salt (1 mol%) efficiently catalyzes a one-pot asymmetric Michael addition/hydroalkoxylation reaction between 1,3-diketones and alkyne-tethered nitroalkenes. Depending on the 1,3-dicarbonyl substrate this cooperative catalytic approach opens access to tetrahydrobenzofurans or annulated dihydropyrans in moderate to excellent yields and very good to excellent enantioselectivities.

Low catalyst loading enabled organocatalytic synthesis of chiral bis-heterocyclic frameworks containing pyrazole and isoxazole

2021 ◽  
Author(s):  
BanniPreet Kaur ◽  
Vivek Sharma ◽  
Subash Chandra Sahoo ◽  
Swapandeep Singh Chimni
Keyword(s):  
Michael Addition ◽  
Addition Reaction ◽  
Catalyst Loading ◽  
Pyrazole Derivatives ◽  
Michael Addition Reaction ◽  
Reaction Conditions ◽  
Low Catalyst Loading

A low-catalyst loading Michael addition reaction of pyrazolyl nitroalkenes with 1,3-dicarbonyl derivatives has been carried out under mild reaction conditions to afford 4-substituted pyrazole derivatives in 60-87% yields and 82-96%...

scholarly journals Asymmetric Michael addition reactions catalyzed by calix[4]thiourea cyclohexanediamine derivatives

2018 ◽  
Vol 14 ◽  
pp. 1901-1907 ◽  
Author(s):  
Zheng-Yi Li ◽  
Hong-Xiao Tong ◽  
Yuan Chen ◽  
Hong-Kui Su ◽  
Tangxin Xiao ◽  
...  
Keyword(s):  
Michael Addition ◽  
Addition Reactions ◽  
Reaction Conditions ◽  
Catalytic Center ◽  
Asymmetric Michael Addition ◽  
Thiourea Group ◽  
High Yields ◽  
Upper Rim ◽  
Optimal Reaction

A number of upper rim-functionalized calix[4]thiourea cyclohexanediamine derivatives have been designed, synthesized and used as catalysts for enantioselective Michael addition reactions between nitroolefins and acetylacetone. The optimal catalyst 2 with a mono-thiourea group exhibited good performance in the presence of water/toluene (v/v = 1:2). Under the optimal reaction conditions, high yields of up to 99% and moderate to good enantioselectivities up to 94% ee were achieved. Detailed experiments clearly showed that the upper rim-functionalized hydrophobic calixarene scaffold played an important role in cooperation with the catalytic center to the good reactivities and enantioselectivities.

Y(OTf)3-catalyzed Phosphorylation of 2H-Chromene Hemiacetals with P(O)-H compounds to 2-Phosphorylated 2H-Chromenes

2021 ◽  
Author(s):  
Long Chen ◽  
Shi-Lu Zheng ◽  
Yun-Xiang Zou ◽  
Zhong Wen ◽  
Jiafu Lin ◽  
...  
Keyword(s):  
Catalyst Loading ◽  
Facile Synthesis ◽  
Reaction Conditions ◽  
Low Catalyst Loading

Facile synthesis of 2-phosphorylated 2H-chromenes has been accomplished herein via a Y(OTf)3-catalyzed dehydrative coupling of 2H-chromene hemiacetals with P(O)-H compounds. This protocol features low catalyst loading, mild reaction conditions, broad...

Three-Component Synthesis of 4-Arylidene-3-alkylisoxazol-5(4H)-ones in the presence of potassium 2,5-dioxoimidazolidin-1-ide

2021 ◽  
Vol 25 ◽  
Author(s):  
Neda Reihani ◽  
Hamzeh Kiyani
Keyword(s):  
Ethylene Glycol ◽  
Ethyl Acetoacetate ◽  
Reaction Medium ◽  
Hydroxylamine Hydrochloride ◽  
Aromatic Aldehydes ◽  
Catalyst Loading ◽  
Efficient Synthesis ◽  
Current Process ◽  
High Yields ◽  
Low Catalyst Loading

: An efficient synthesis of 4-arylidene-3-alkylisoxazole-5(4H)-ones has been implemented via the three-component cyclocondensation of aryl(heteroaryl)aldehydes with hydroxylamine hydrochloride and β-ketoesters. The potassium 2,5-dioxoimidazolidin-1-ide has been introduced as the new organocatalyst to facilitate of this heterocyclization. In the current process, three starting materials, including substituted benzaldehydes/heterocyclic aromatic aldehydes, hydroxylamine hydrochloride, and ethyl acetoacetate/propyl acetoacetate/butyryl acetoacetate have been successfully used for the synthesize of the number of substituted isoxazole-5(4H)-ones in good to high yields in ethylene glycol as a green reaction medium at 80 ºC. The low catalyst loading is also a main advantage over the some reported catalysts.

Synthesis of 4-arylethyl-6-arylpyrimidine-2-thiols through aza-Michael addition/nucleophilic addition/aromatization tandem reactions

2018 ◽  
Vol 24 (1) ◽  
pp. 23-26
Author(s):  
Zheng Li ◽  
Wenli Song ◽  
Jiaojiao He ◽  
Yan Du ◽  
Jingya Yang
Keyword(s):  
Efficient Method ◽  
Michael Addition ◽  
Nucleophilic Addition ◽  
Tandem Reactions ◽  
Reaction Conditions ◽  
High Yields ◽  
Work Up

Abstract An efficient method for the synthesis of the title compounds by reactions of divinyl ketones with thiourea is described. This protocol has the advantages of high yields, mild reaction conditions and simple work-up procedure.

Sugar Based γ-Amino Alcohol Organocatalyst for Asymmetric Michael Addition of β-Keto Esters with Nitroolefins

Heterocycles ◽  
2019 ◽  
Vol 98 (11) ◽  
pp. 1536 ◽  
Author(s):  
Hiroto Nakano ◽  
Divakar Ganesan ◽  
Madhu Chennapuram ◽  
Zubeda Begum ◽  
Chigusa Seki ◽  
...  
Keyword(s):  
Michael Addition ◽  
Amino Alcohol ◽  
Keto Esters ◽  
Asymmetric Michael Addition
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