Enantioselective synthesis of chiral heterocycles containing both chroman and pyrazolone derivatives catalysed by a chiral squaramide

2015 ◽  
Vol 13 (20) ◽  
pp. 5636-5645 ◽  
Author(s):  
Jun-Hua Li ◽  
Da-Ming Du
Keyword(s):  
Michael Addition ◽  
Enantioselective Synthesis ◽  
Catalyst Loading ◽  
Pyrazolone Derivatives ◽  
Low Catalyst Loading

An efficient chiral squaramide-catalysed enantioselective Michael addition of pyrazolin-5-ones to 3-nitro-2H-chromenes afforded chiral heterocycles containing both chroman and pyrazolone derivatives in high to excellent yields (up to 98%) with high enantioselectivities (up to 96%) under very low catalyst loading (0.2 mol%).

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 %).

Peptidomimetic organocatalysts: efficient Michael addition of ketones onto nitroolefins with very low catalyst loading

RSC Advances ◽  
2014 ◽  
Vol 4 (57) ◽  
pp. 30325-30331 ◽  
Author(s):  
Srivari Chandrasekhar ◽  
Chintakunta Praveen Kumar ◽  
Togapur Pavan Kumar ◽  
Kothapalli Haribabu ◽  
Bharatam Jagadeesh ◽  
...  
Keyword(s):  
Michael Addition ◽  
Michael Reaction ◽  
Catalyst Loading ◽  
Low Catalyst Loading

The syntheses and applications of peptidomimetic triazole-based catalysts are described as efficient organocatalysts in Michael reaction with low loading.

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.

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.

ChemInform Abstract: Peptidomimetic Organocatalysts: Efficient Michael Addition of Ketones onto Nitroolefins with Very Low Catalyst Loading.

ChemInform ◽  
2015 ◽  
Vol 46 (7) ◽  
pp. no-no ◽  
Author(s):  
Srivari Chandrasekhar ◽  
Chintakunta Praveen Kumar ◽  
Togapur Pavan Kumar ◽  
Kothapalli Haribabu ◽  
Bharatam Jagadeesh ◽  
...  
Keyword(s):  
Michael Addition ◽  
Catalyst Loading ◽  
Low Catalyst Loading

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%...

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...

scholarly journals Enantioselective amination of 4-alkylisoquinoline-1,3(2H,4H)-dione derivatives

RSC Advances ◽  
2020 ◽  
Vol 10 (70) ◽  
pp. 42912-42915
Author(s):  
Cheng Cheng ◽  
Ying-Xian Li ◽  
Xue-Min Jia ◽  
Ji-Quan Zhang ◽  
Yong-Long Zhao ◽  
...  
Keyword(s):  
Catalyst Loading ◽  
Low Catalyst Loading

A mild and efficient enantioselective amination of 4-alkylisoquinoline-1,3(2H,4H)-dione derivatives was established and a broad range of amination products were prepared in excellent yields and ee values with low catalyst loading.

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