scholarly journals Synthesis of non-racemic 4-nitro-2-sulfonylbutan-1-ones via Ni(II)-catalyzed asymmetric Michael reaction of β-ketosulfones

2019 ◽  
Vol 15 ◽  
pp. 1289-1297 ◽  
Author(s):  
Alexander N Reznikov ◽  
Anastasiya E Sibiryakova ◽  
Marat R Baimuratov ◽  
Eugene V Golovin ◽  
Victor B Rybakov ◽  
...  

Functionally substituted sulfones with stereogenic centers are valuable reagents in organic synthesis and key motifs in some bioactive compounds. The asymmetric Michael addition of β-ketosulfones to conjugated nitroalkenes in the presence of Ni(II) complexes with various chiral vicinal diamines was studied. This reaction provides convenient access to non-racemic 4-nitro-2-sulfonylbutan-1-ones with two stereocenters with high yield and excellent enantioselectivity (up to 99%). It has been established that the catalytic Michael reaction itself was carried out with high diastereoselectivity, but the Michael adducts may epimerize at the C-2 position at a significant rate. Conditions for the preparation of individual diastereomers were found.

2015 ◽  
Vol 13 (17) ◽  
pp. 5054-5060 ◽  
Author(s):  
Xiaochen Ren ◽  
Chunyan He ◽  
Yingle Feng ◽  
Yonghai Chai ◽  
Wei Yao ◽  
...  

An efficient method was developed to synthesize the ferrocene-based bifunctional amine–thioureas bearing multiple hydrogen-bonding donors. Asymmetric Michael addition of acetylacetone to nitroolefins catalyzed by these novel bifunctional catalysts affords the Michael adducts in high yield and moderate to excellent enantioselectivities.


2020 ◽  
Vol 7 (11) ◽  
pp. 1343-1348
Author(s):  
Luyao Li ◽  
Bo Zhu ◽  
Huihui Fan ◽  
Zhiyong Jiang ◽  
Junbiao Chang

Herein, we report a chiral bifunctional thiourea catalyzed asymmetric Michael addition reaction between 2-(trifluoromethyl)oxazol-5(2H)-one as a direct C-2-position nucleophile to 4-nitro-5-styrylisoxazoles for the first time.


2015 ◽  
Vol 13 (25) ◽  
pp. 7076-7083 ◽  
Author(s):  
Utpal Nath ◽  
Ankush Banerjee ◽  
Bidhan Ghosh ◽  
Subhas Chandra Pan

The first organocatalytic asymmetric Michael reaction between α-branched enones namely 1-acetylcyclohexene, 1-acetylcyclopentene and 1-acetylcyclobutene with nitroolefins has been developed using primary amines as catalysts.


Synthesis ◽  
2018 ◽  
Vol 50 (13) ◽  
pp. 2577-2586 ◽  
Author(s):  
Jia-Ni Yuan ◽  
Hui-Xia Liu ◽  
Qin-Qin Tian ◽  
Nan Ji ◽  
Kuo Shen ◽  
...  

We report a highly efficient asymmetric Michael addition of dithiomalonates to trans-β-nitroolefins catalyzed by versatile cinchona-based bifunctional thioureas, which provides the corresponding adducts in high yields (up to 92%) and with excellent enantioselectivities (up to 99% ee) under mild conditions. Replacement of the catalyst with its pseudo-enantiomer gives the Michael adducts with opposite configuration in similar yields and enantioselectivities.


2007 ◽  
Vol 62 (4) ◽  
pp. 556-560 ◽  
Author(s):  
Jae-Chul Jung ◽  
Oee-Sook Park

A simple synthesis of prostaglandin E1 (PGE1) is described. The key steps are an asymmetric Michael addition to establish the desired (R)-configurations at C8 and C12 of the 2- (trimethylsilyl)ethoxymethyl- (SEM) protected PGE1 and its one-pot deprotection with magnesium bromide in high yield. This method is potentially useful for the preparation of other modified prostaglandins.


2021 ◽  
Vol 17 ◽  
pp. 494-503
Author(s):  
Deniz Tözendemir ◽  
Cihangir Tanyeli

Cinchona alkaloid-derived organocatalysts are widely employed in various asymmetric transformations, yielding products with high enantiopurity. In this respect, a bifunctional quinine-derived sulfonamide organocatalyst was developed to catalyze the asymmetric sulfa-Michael reaction of naphthalene-1-thiol with trans-chalcone derivatives. The target sulfa-Michael adducts were obtained with up to 96% ee under mild conditions and with a low (1 mol %) catalyst loading. Selected enantiomerically enriched sulfa-Michael addition products were subjected to oxidation to obtain the corresponding sulfones.


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